1 Booting the Linux/ppc kernel without Open Firmware 2 -------------------------------------------------- 3 4(c) 2005 Benjamin Herrenschmidt <benh at kernel.crashing.org>, 5 IBM Corp. 6(c) 2005 Becky Bruce <becky.bruce at freescale.com>, 7 Freescale Semiconductor, FSL SOC and 32-bit additions 8(c) 2006 MontaVista Software, Inc. 9 Flash chip node definition 10 11Table of Contents 12================= 13 14 I - Introduction 15 1) Entry point for arch/powerpc 16 2) Board support 17 18 II - The DT block format 19 1) Header 20 2) Device tree generalities 21 3) Device tree "structure" block 22 4) Device tree "strings" block 23 24 III - Required content of the device tree 25 1) Note about cells and address representation 26 2) Note about "compatible" properties 27 3) Note about "name" properties 28 4) Note about node and property names and character set 29 5) Required nodes and properties 30 a) The root node 31 b) The /cpus node 32 c) The /cpus/* nodes 33 d) the /memory node(s) 34 e) The /chosen node 35 f) the /soc<SOCname> node 36 37 IV - "dtc", the device tree compiler 38 39 V - Recommendations for a bootloader 40 41 VI - System-on-a-chip devices and nodes 42 1) Defining child nodes of an SOC 43 2) Representing devices without a current OF specification 44 a) PHY nodes 45 b) Interrupt controllers 46 c) 4xx/Axon EMAC ethernet nodes 47 d) Xilinx IP cores 48 e) USB EHCI controllers 49 f) MDIO on GPIOs 50 g) SPI busses 51 52 VII - Specifying interrupt information for devices 53 1) interrupts property 54 2) interrupt-parent property 55 3) OpenPIC Interrupt Controllers 56 4) ISA Interrupt Controllers 57 58 VIII - Specifying device power management information (sleep property) 59 60 Appendix A - Sample SOC node for MPC8540 61 62 63Revision Information 64==================== 65 66 May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet. 67 68 May 19, 2005: Rev 0.2 - Add chapter III and bits & pieces here or 69 clarifies the fact that a lot of things are 70 optional, the kernel only requires a very 71 small device tree, though it is encouraged 72 to provide an as complete one as possible. 73 74 May 24, 2005: Rev 0.3 - Precise that DT block has to be in RAM 75 - Misc fixes 76 - Define version 3 and new format version 16 77 for the DT block (version 16 needs kernel 78 patches, will be fwd separately). 79 String block now has a size, and full path 80 is replaced by unit name for more 81 compactness. 82 linux,phandle is made optional, only nodes 83 that are referenced by other nodes need it. 84 "name" property is now automatically 85 deduced from the unit name 86 87 June 1, 2005: Rev 0.4 - Correct confusion between OF_DT_END and 88 OF_DT_END_NODE in structure definition. 89 - Change version 16 format to always align 90 property data to 4 bytes. Since tokens are 91 already aligned, that means no specific 92 required alignment between property size 93 and property data. The old style variable 94 alignment would make it impossible to do 95 "simple" insertion of properties using 96 memmove (thanks Milton for 97 noticing). Updated kernel patch as well 98 - Correct a few more alignment constraints 99 - Add a chapter about the device-tree 100 compiler and the textural representation of 101 the tree that can be "compiled" by dtc. 102 103 November 21, 2005: Rev 0.5 104 - Additions/generalizations for 32-bit 105 - Changed to reflect the new arch/powerpc 106 structure 107 - Added chapter VI 108 109 110 ToDo: 111 - Add some definitions of interrupt tree (simple/complex) 112 - Add some definitions for PCI host bridges 113 - Add some common address format examples 114 - Add definitions for standard properties and "compatible" 115 names for cells that are not already defined by the existing 116 OF spec. 117 - Compare FSL SOC use of PCI to standard and make sure no new 118 node definition required. 119 - Add more information about node definitions for SOC devices 120 that currently have no standard, like the FSL CPM. 121 122 123I - Introduction 124================ 125 126During the recent development of the Linux/ppc64 kernel, and more 127specifically, the addition of new platform types outside of the old 128IBM pSeries/iSeries pair, it was decided to enforce some strict rules 129regarding the kernel entry and bootloader <-> kernel interfaces, in 130order to avoid the degeneration that had become the ppc32 kernel entry 131point and the way a new platform should be added to the kernel. The 132legacy iSeries platform breaks those rules as it predates this scheme, 133but no new board support will be accepted in the main tree that 134doesn't follows them properly. In addition, since the advent of the 135arch/powerpc merged architecture for ppc32 and ppc64, new 32-bit 136platforms and 32-bit platforms which move into arch/powerpc will be 137required to use these rules as well. 138 139The main requirement that will be defined in more detail below is 140the presence of a device-tree whose format is defined after Open 141Firmware specification. However, in order to make life easier 142to embedded board vendors, the kernel doesn't require the device-tree 143to represent every device in the system and only requires some nodes 144and properties to be present. This will be described in detail in 145section III, but, for example, the kernel does not require you to 146create a node for every PCI device in the system. It is a requirement 147to have a node for PCI host bridges in order to provide interrupt 148routing informations and memory/IO ranges, among others. It is also 149recommended to define nodes for on chip devices and other busses that 150don't specifically fit in an existing OF specification. This creates a 151great flexibility in the way the kernel can then probe those and match 152drivers to device, without having to hard code all sorts of tables. It 153also makes it more flexible for board vendors to do minor hardware 154upgrades without significantly impacting the kernel code or cluttering 155it with special cases. 156 157 1581) Entry point for arch/powerpc 159------------------------------- 160 161 There is one and one single entry point to the kernel, at the start 162 of the kernel image. That entry point supports two calling 163 conventions: 164 165 a) Boot from Open Firmware. If your firmware is compatible 166 with Open Firmware (IEEE 1275) or provides an OF compatible 167 client interface API (support for "interpret" callback of 168 forth words isn't required), you can enter the kernel with: 169 170 r5 : OF callback pointer as defined by IEEE 1275 171 bindings to powerpc. Only the 32-bit client interface 172 is currently supported 173 174 r3, r4 : address & length of an initrd if any or 0 175 176 The MMU is either on or off; the kernel will run the 177 trampoline located in arch/powerpc/kernel/prom_init.c to 178 extract the device-tree and other information from open 179 firmware and build a flattened device-tree as described 180 in b). prom_init() will then re-enter the kernel using 181 the second method. This trampoline code runs in the 182 context of the firmware, which is supposed to handle all 183 exceptions during that time. 184 185 b) Direct entry with a flattened device-tree block. This entry 186 point is called by a) after the OF trampoline and can also be 187 called directly by a bootloader that does not support the Open 188 Firmware client interface. It is also used by "kexec" to 189 implement "hot" booting of a new kernel from a previous 190 running one. This method is what I will describe in more 191 details in this document, as method a) is simply standard Open 192 Firmware, and thus should be implemented according to the 193 various standard documents defining it and its binding to the 194 PowerPC platform. The entry point definition then becomes: 195 196 r3 : physical pointer to the device-tree block 197 (defined in chapter II) in RAM 198 199 r4 : physical pointer to the kernel itself. This is 200 used by the assembly code to properly disable the MMU 201 in case you are entering the kernel with MMU enabled 202 and a non-1:1 mapping. 203 204 r5 : NULL (as to differentiate with method a) 205 206 Note about SMP entry: Either your firmware puts your other 207 CPUs in some sleep loop or spin loop in ROM where you can get 208 them out via a soft reset or some other means, in which case 209 you don't need to care, or you'll have to enter the kernel 210 with all CPUs. The way to do that with method b) will be 211 described in a later revision of this document. 212 213 2142) Board support 215---------------- 216 21764-bit kernels: 218 219 Board supports (platforms) are not exclusive config options. An 220 arbitrary set of board supports can be built in a single kernel 221 image. The kernel will "know" what set of functions to use for a 222 given platform based on the content of the device-tree. Thus, you 223 should: 224 225 a) add your platform support as a _boolean_ option in 226 arch/powerpc/Kconfig, following the example of PPC_PSERIES, 227 PPC_PMAC and PPC_MAPLE. The later is probably a good 228 example of a board support to start from. 229 230 b) create your main platform file as 231 "arch/powerpc/platforms/myplatform/myboard_setup.c" and add it 232 to the Makefile under the condition of your CONFIG_ 233 option. This file will define a structure of type "ppc_md" 234 containing the various callbacks that the generic code will 235 use to get to your platform specific code 236 237 c) Add a reference to your "ppc_md" structure in the 238 "machines" table in arch/powerpc/kernel/setup_64.c if you are 239 a 64-bit platform. 240 241 d) request and get assigned a platform number (see PLATFORM_* 242 constants in arch/powerpc/include/asm/processor.h 243 24432-bit embedded kernels: 245 246 Currently, board support is essentially an exclusive config option. 247 The kernel is configured for a single platform. Part of the reason 248 for this is to keep kernels on embedded systems small and efficient; 249 part of this is due to the fact the code is already that way. In the 250 future, a kernel may support multiple platforms, but only if the 251 platforms feature the same core architecture. A single kernel build 252 cannot support both configurations with Book E and configurations 253 with classic Powerpc architectures. 254 255 32-bit embedded platforms that are moved into arch/powerpc using a 256 flattened device tree should adopt the merged tree practice of 257 setting ppc_md up dynamically, even though the kernel is currently 258 built with support for only a single platform at a time. This allows 259 unification of the setup code, and will make it easier to go to a 260 multiple-platform-support model in the future. 261 262NOTE: I believe the above will be true once Ben's done with the merge 263of the boot sequences.... someone speak up if this is wrong! 264 265 To add a 32-bit embedded platform support, follow the instructions 266 for 64-bit platforms above, with the exception that the Kconfig 267 option should be set up such that the kernel builds exclusively for 268 the platform selected. The processor type for the platform should 269 enable another config option to select the specific board 270 supported. 271 272NOTE: If Ben doesn't merge the setup files, may need to change this to 273point to setup_32.c 274 275 276 I will describe later the boot process and various callbacks that 277 your platform should implement. 278 279 280II - The DT block format 281======================== 282 283 284This chapter defines the actual format of the flattened device-tree 285passed to the kernel. The actual content of it and kernel requirements 286are described later. You can find example of code manipulating that 287format in various places, including arch/powerpc/kernel/prom_init.c 288which will generate a flattened device-tree from the Open Firmware 289representation, or the fs2dt utility which is part of the kexec tools 290which will generate one from a filesystem representation. It is 291expected that a bootloader like uboot provides a bit more support, 292that will be discussed later as well. 293 294Note: The block has to be in main memory. It has to be accessible in 295both real mode and virtual mode with no mapping other than main 296memory. If you are writing a simple flash bootloader, it should copy 297the block to RAM before passing it to the kernel. 298 299 3001) Header 301--------- 302 303 The kernel is entered with r3 pointing to an area of memory that is 304 roughly described in arch/powerpc/include/asm/prom.h by the structure 305 boot_param_header: 306 307struct boot_param_header { 308 u32 magic; /* magic word OF_DT_HEADER */ 309 u32 totalsize; /* total size of DT block */ 310 u32 off_dt_struct; /* offset to structure */ 311 u32 off_dt_strings; /* offset to strings */ 312 u32 off_mem_rsvmap; /* offset to memory reserve map 313 */ 314 u32 version; /* format version */ 315 u32 last_comp_version; /* last compatible version */ 316 317 /* version 2 fields below */ 318 u32 boot_cpuid_phys; /* Which physical CPU id we're 319 booting on */ 320 /* version 3 fields below */ 321 u32 size_dt_strings; /* size of the strings block */ 322 323 /* version 17 fields below */ 324 u32 size_dt_struct; /* size of the DT structure block */ 325}; 326 327 Along with the constants: 328 329/* Definitions used by the flattened device tree */ 330#define OF_DT_HEADER 0xd00dfeed /* 4: version, 331 4: total size */ 332#define OF_DT_BEGIN_NODE 0x1 /* Start node: full name 333 */ 334#define OF_DT_END_NODE 0x2 /* End node */ 335#define OF_DT_PROP 0x3 /* Property: name off, 336 size, content */ 337#define OF_DT_END 0x9 338 339 All values in this header are in big endian format, the various 340 fields in this header are defined more precisely below. All 341 "offset" values are in bytes from the start of the header; that is 342 from the value of r3. 343 344 - magic 345 346 This is a magic value that "marks" the beginning of the 347 device-tree block header. It contains the value 0xd00dfeed and is 348 defined by the constant OF_DT_HEADER 349 350 - totalsize 351 352 This is the total size of the DT block including the header. The 353 "DT" block should enclose all data structures defined in this 354 chapter (who are pointed to by offsets in this header). That is, 355 the device-tree structure, strings, and the memory reserve map. 356 357 - off_dt_struct 358 359 This is an offset from the beginning of the header to the start 360 of the "structure" part the device tree. (see 2) device tree) 361 362 - off_dt_strings 363 364 This is an offset from the beginning of the header to the start 365 of the "strings" part of the device-tree 366 367 - off_mem_rsvmap 368 369 This is an offset from the beginning of the header to the start 370 of the reserved memory map. This map is a list of pairs of 64- 371 bit integers. Each pair is a physical address and a size. The 372 list is terminated by an entry of size 0. This map provides the 373 kernel with a list of physical memory areas that are "reserved" 374 and thus not to be used for memory allocations, especially during 375 early initialization. The kernel needs to allocate memory during 376 boot for things like un-flattening the device-tree, allocating an 377 MMU hash table, etc... Those allocations must be done in such a 378 way to avoid overriding critical things like, on Open Firmware 379 capable machines, the RTAS instance, or on some pSeries, the TCE 380 tables used for the iommu. Typically, the reserve map should 381 contain _at least_ this DT block itself (header,total_size). If 382 you are passing an initrd to the kernel, you should reserve it as 383 well. You do not need to reserve the kernel image itself. The map 384 should be 64-bit aligned. 385 386 - version 387 388 This is the version of this structure. Version 1 stops 389 here. Version 2 adds an additional field boot_cpuid_phys. 390 Version 3 adds the size of the strings block, allowing the kernel 391 to reallocate it easily at boot and free up the unused flattened 392 structure after expansion. Version 16 introduces a new more 393 "compact" format for the tree itself that is however not backward 394 compatible. Version 17 adds an additional field, size_dt_struct, 395 allowing it to be reallocated or moved more easily (this is 396 particularly useful for bootloaders which need to make 397 adjustments to a device tree based on probed information). You 398 should always generate a structure of the highest version defined 399 at the time of your implementation. Currently that is version 17, 400 unless you explicitly aim at being backward compatible. 401 402 - last_comp_version 403 404 Last compatible version. This indicates down to what version of 405 the DT block you are backward compatible. For example, version 2 406 is backward compatible with version 1 (that is, a kernel build 407 for version 1 will be able to boot with a version 2 format). You 408 should put a 1 in this field if you generate a device tree of 409 version 1 to 3, or 16 if you generate a tree of version 16 or 17 410 using the new unit name format. 411 412 - boot_cpuid_phys 413 414 This field only exist on version 2 headers. It indicate which 415 physical CPU ID is calling the kernel entry point. This is used, 416 among others, by kexec. If you are on an SMP system, this value 417 should match the content of the "reg" property of the CPU node in 418 the device-tree corresponding to the CPU calling the kernel entry 419 point (see further chapters for more informations on the required 420 device-tree contents) 421 422 - size_dt_strings 423 424 This field only exists on version 3 and later headers. It 425 gives the size of the "strings" section of the device tree (which 426 starts at the offset given by off_dt_strings). 427 428 - size_dt_struct 429 430 This field only exists on version 17 and later headers. It gives 431 the size of the "structure" section of the device tree (which 432 starts at the offset given by off_dt_struct). 433 434 So the typical layout of a DT block (though the various parts don't 435 need to be in that order) looks like this (addresses go from top to 436 bottom): 437 438 439 ------------------------------ 440 r3 -> | struct boot_param_header | 441 ------------------------------ 442 | (alignment gap) (*) | 443 ------------------------------ 444 | memory reserve map | 445 ------------------------------ 446 | (alignment gap) | 447 ------------------------------ 448 | | 449 | device-tree structure | 450 | | 451 ------------------------------ 452 | (alignment gap) | 453 ------------------------------ 454 | | 455 | device-tree strings | 456 | | 457 -----> ------------------------------ 458 | 459 | 460 --- (r3 + totalsize) 461 462 (*) The alignment gaps are not necessarily present; their presence 463 and size are dependent on the various alignment requirements of 464 the individual data blocks. 465 466 4672) Device tree generalities 468--------------------------- 469 470This device-tree itself is separated in two different blocks, a 471structure block and a strings block. Both need to be aligned to a 4 472byte boundary. 473 474First, let's quickly describe the device-tree concept before detailing 475the storage format. This chapter does _not_ describe the detail of the 476required types of nodes & properties for the kernel, this is done 477later in chapter III. 478 479The device-tree layout is strongly inherited from the definition of 480the Open Firmware IEEE 1275 device-tree. It's basically a tree of 481nodes, each node having two or more named properties. A property can 482have a value or not. 483 484It is a tree, so each node has one and only one parent except for the 485root node who has no parent. 486 487A node has 2 names. The actual node name is generally contained in a 488property of type "name" in the node property list whose value is a 489zero terminated string and is mandatory for version 1 to 3 of the 490format definition (as it is in Open Firmware). Version 16 makes it 491optional as it can generate it from the unit name defined below. 492 493There is also a "unit name" that is used to differentiate nodes with 494the same name at the same level, it is usually made of the node 495names, the "@" sign, and a "unit address", which definition is 496specific to the bus type the node sits on. 497 498The unit name doesn't exist as a property per-se but is included in 499the device-tree structure. It is typically used to represent "path" in 500the device-tree. More details about the actual format of these will be 501below. 502 503The kernel powerpc generic code does not make any formal use of the 504unit address (though some board support code may do) so the only real 505requirement here for the unit address is to ensure uniqueness of 506the node unit name at a given level of the tree. Nodes with no notion 507of address and no possible sibling of the same name (like /memory or 508/cpus) may omit the unit address in the context of this specification, 509or use the "@0" default unit address. The unit name is used to define 510a node "full path", which is the concatenation of all parent node 511unit names separated with "/". 512 513The root node doesn't have a defined name, and isn't required to have 514a name property either if you are using version 3 or earlier of the 515format. It also has no unit address (no @ symbol followed by a unit 516address). The root node unit name is thus an empty string. The full 517path to the root node is "/". 518 519Every node which actually represents an actual device (that is, a node 520which isn't only a virtual "container" for more nodes, like "/cpus" 521is) is also required to have a "device_type" property indicating the 522type of node . 523 524Finally, every node that can be referenced from a property in another 525node is required to have a "linux,phandle" property. Real open 526firmware implementations provide a unique "phandle" value for every 527node that the "prom_init()" trampoline code turns into 528"linux,phandle" properties. However, this is made optional if the 529flattened device tree is used directly. An example of a node 530referencing another node via "phandle" is when laying out the 531interrupt tree which will be described in a further version of this 532document. 533 534This "linux, phandle" property is a 32-bit value that uniquely 535identifies a node. You are free to use whatever values or system of 536values, internal pointers, or whatever to generate these, the only 537requirement is that every node for which you provide that property has 538a unique value for it. 539 540Here is an example of a simple device-tree. In this example, an "o" 541designates a node followed by the node unit name. Properties are 542presented with their name followed by their content. "content" 543represents an ASCII string (zero terminated) value, while <content> 544represents a 32-bit hexadecimal value. The various nodes in this 545example will be discussed in a later chapter. At this point, it is 546only meant to give you a idea of what a device-tree looks like. I have 547purposefully kept the "name" and "linux,phandle" properties which 548aren't necessary in order to give you a better idea of what the tree 549looks like in practice. 550 551 / o device-tree 552 |- name = "device-tree" 553 |- model = "MyBoardName" 554 |- compatible = "MyBoardFamilyName" 555 |- #address-cells = <2> 556 |- #size-cells = <2> 557 |- linux,phandle = <0> 558 | 559 o cpus 560 | | - name = "cpus" 561 | | - linux,phandle = <1> 562 | | - #address-cells = <1> 563 | | - #size-cells = <0> 564 | | 565 | o PowerPC,970@0 566 | |- name = "PowerPC,970" 567 | |- device_type = "cpu" 568 | |- reg = <0> 569 | |- clock-frequency = <5f5e1000> 570 | |- 64-bit 571 | |- linux,phandle = <2> 572 | 573 o memory@0 574 | |- name = "memory" 575 | |- device_type = "memory" 576 | |- reg = <00000000 00000000 00000000 20000000> 577 | |- linux,phandle = <3> 578 | 579 o chosen 580 |- name = "chosen" 581 |- bootargs = "root=/dev/sda2" 582 |- linux,phandle = <4> 583 584This tree is almost a minimal tree. It pretty much contains the 585minimal set of required nodes and properties to boot a linux kernel; 586that is, some basic model informations at the root, the CPUs, and the 587physical memory layout. It also includes misc information passed 588through /chosen, like in this example, the platform type (mandatory) 589and the kernel command line arguments (optional). 590 591The /cpus/PowerPC,970@0/64-bit property is an example of a 592property without a value. All other properties have a value. The 593significance of the #address-cells and #size-cells properties will be 594explained in chapter IV which defines precisely the required nodes and 595properties and their content. 596 597 5983) Device tree "structure" block 599 600The structure of the device tree is a linearized tree structure. The 601"OF_DT_BEGIN_NODE" token starts a new node, and the "OF_DT_END_NODE" 602ends that node definition. Child nodes are simply defined before 603"OF_DT_END_NODE" (that is nodes within the node). A 'token' is a 32 604bit value. The tree has to be "finished" with a OF_DT_END token 605 606Here's the basic structure of a single node: 607 608 * token OF_DT_BEGIN_NODE (that is 0x00000001) 609 * for version 1 to 3, this is the node full path as a zero 610 terminated string, starting with "/". For version 16 and later, 611 this is the node unit name only (or an empty string for the 612 root node) 613 * [align gap to next 4 bytes boundary] 614 * for each property: 615 * token OF_DT_PROP (that is 0x00000003) 616 * 32-bit value of property value size in bytes (or 0 if no 617 value) 618 * 32-bit value of offset in string block of property name 619 * property value data if any 620 * [align gap to next 4 bytes boundary] 621 * [child nodes if any] 622 * token OF_DT_END_NODE (that is 0x00000002) 623 624So the node content can be summarized as a start token, a full path, 625a list of properties, a list of child nodes, and an end token. Every 626child node is a full node structure itself as defined above. 627 628NOTE: The above definition requires that all property definitions for 629a particular node MUST precede any subnode definitions for that node. 630Although the structure would not be ambiguous if properties and 631subnodes were intermingled, the kernel parser requires that the 632properties come first (up until at least 2.6.22). Any tools 633manipulating a flattened tree must take care to preserve this 634constraint. 635 6364) Device tree "strings" block 637 638In order to save space, property names, which are generally redundant, 639are stored separately in the "strings" block. This block is simply the 640whole bunch of zero terminated strings for all property names 641concatenated together. The device-tree property definitions in the 642structure block will contain offset values from the beginning of the 643strings block. 644 645 646III - Required content of the device tree 647========================================= 648 649WARNING: All "linux,*" properties defined in this document apply only 650to a flattened device-tree. If your platform uses a real 651implementation of Open Firmware or an implementation compatible with 652the Open Firmware client interface, those properties will be created 653by the trampoline code in the kernel's prom_init() file. For example, 654that's where you'll have to add code to detect your board model and 655set the platform number. However, when using the flattened device-tree 656entry point, there is no prom_init() pass, and thus you have to 657provide those properties yourself. 658 659 6601) Note about cells and address representation 661---------------------------------------------- 662 663The general rule is documented in the various Open Firmware 664documentations. If you choose to describe a bus with the device-tree 665and there exist an OF bus binding, then you should follow the 666specification. However, the kernel does not require every single 667device or bus to be described by the device tree. 668 669In general, the format of an address for a device is defined by the 670parent bus type, based on the #address-cells and #size-cells 671properties. Note that the parent's parent definitions of #address-cells 672and #size-cells are not inherited so every node with children must specify 673them. The kernel requires the root node to have those properties defining 674addresses format for devices directly mapped on the processor bus. 675 676Those 2 properties define 'cells' for representing an address and a 677size. A "cell" is a 32-bit number. For example, if both contain 2 678like the example tree given above, then an address and a size are both 679composed of 2 cells, and each is a 64-bit number (cells are 680concatenated and expected to be in big endian format). Another example 681is the way Apple firmware defines them, with 2 cells for an address 682and one cell for a size. Most 32-bit implementations should define 683#address-cells and #size-cells to 1, which represents a 32-bit value. 684Some 32-bit processors allow for physical addresses greater than 32 685bits; these processors should define #address-cells as 2. 686 687"reg" properties are always a tuple of the type "address size" where 688the number of cells of address and size is specified by the bus 689#address-cells and #size-cells. When a bus supports various address 690spaces and other flags relative to a given address allocation (like 691prefetchable, etc...) those flags are usually added to the top level 692bits of the physical address. For example, a PCI physical address is 693made of 3 cells, the bottom two containing the actual address itself 694while the top cell contains address space indication, flags, and pci 695bus & device numbers. 696 697For busses that support dynamic allocation, it's the accepted practice 698to then not provide the address in "reg" (keep it 0) though while 699providing a flag indicating the address is dynamically allocated, and 700then, to provide a separate "assigned-addresses" property that 701contains the fully allocated addresses. See the PCI OF bindings for 702details. 703 704In general, a simple bus with no address space bits and no dynamic 705allocation is preferred if it reflects your hardware, as the existing 706kernel address parsing functions will work out of the box. If you 707define a bus type with a more complex address format, including things 708like address space bits, you'll have to add a bus translator to the 709prom_parse.c file of the recent kernels for your bus type. 710 711The "reg" property only defines addresses and sizes (if #size-cells is 712non-0) within a given bus. In order to translate addresses upward 713(that is into parent bus addresses, and possibly into CPU physical 714addresses), all busses must contain a "ranges" property. If the 715"ranges" property is missing at a given level, it's assumed that 716translation isn't possible, i.e., the registers are not visible on the 717parent bus. The format of the "ranges" property for a bus is a list 718of: 719 720 bus address, parent bus address, size 721 722"bus address" is in the format of the bus this bus node is defining, 723that is, for a PCI bridge, it would be a PCI address. Thus, (bus 724address, size) defines a range of addresses for child devices. "parent 725bus address" is in the format of the parent bus of this bus. For 726example, for a PCI host controller, that would be a CPU address. For a 727PCI<->ISA bridge, that would be a PCI address. It defines the base 728address in the parent bus where the beginning of that range is mapped. 729 730For a new 64-bit powerpc board, I recommend either the 2/2 format or 731Apple's 2/1 format which is slightly more compact since sizes usually 732fit in a single 32-bit word. New 32-bit powerpc boards should use a 7331/1 format, unless the processor supports physical addresses greater 734than 32-bits, in which case a 2/1 format is recommended. 735 736Alternatively, the "ranges" property may be empty, indicating that the 737registers are visible on the parent bus using an identity mapping 738translation. In other words, the parent bus address space is the same 739as the child bus address space. 740 7412) Note about "compatible" properties 742------------------------------------- 743 744These properties are optional, but recommended in devices and the root 745node. The format of a "compatible" property is a list of concatenated 746zero terminated strings. They allow a device to express its 747compatibility with a family of similar devices, in some cases, 748allowing a single driver to match against several devices regardless 749of their actual names. 750 7513) Note about "name" properties 752------------------------------- 753 754While earlier users of Open Firmware like OldWorld macintoshes tended 755to use the actual device name for the "name" property, it's nowadays 756considered a good practice to use a name that is closer to the device 757class (often equal to device_type). For example, nowadays, ethernet 758controllers are named "ethernet", an additional "model" property 759defining precisely the chip type/model, and "compatible" property 760defining the family in case a single driver can driver more than one 761of these chips. However, the kernel doesn't generally put any 762restriction on the "name" property; it is simply considered good 763practice to follow the standard and its evolutions as closely as 764possible. 765 766Note also that the new format version 16 makes the "name" property 767optional. If it's absent for a node, then the node's unit name is then 768used to reconstruct the name. That is, the part of the unit name 769before the "@" sign is used (or the entire unit name if no "@" sign 770is present). 771 7724) Note about node and property names and character set 773------------------------------------------------------- 774 775While open firmware provides more flexible usage of 8859-1, this 776specification enforces more strict rules. Nodes and properties should 777be comprised only of ASCII characters 'a' to 'z', '0' to 778'9', ',', '.', '_', '+', '#', '?', and '-'. Node names additionally 779allow uppercase characters 'A' to 'Z' (property names should be 780lowercase. The fact that vendors like Apple don't respect this rule is 781irrelevant here). Additionally, node and property names should always 782begin with a character in the range 'a' to 'z' (or 'A' to 'Z' for node 783names). 784 785The maximum number of characters for both nodes and property names 786is 31. In the case of node names, this is only the leftmost part of 787a unit name (the pure "name" property), it doesn't include the unit 788address which can extend beyond that limit. 789 790 7915) Required nodes and properties 792-------------------------------- 793 These are all that are currently required. However, it is strongly 794 recommended that you expose PCI host bridges as documented in the 795 PCI binding to open firmware, and your interrupt tree as documented 796 in OF interrupt tree specification. 797 798 a) The root node 799 800 The root node requires some properties to be present: 801 802 - model : this is your board name/model 803 - #address-cells : address representation for "root" devices 804 - #size-cells: the size representation for "root" devices 805 - device_type : This property shouldn't be necessary. However, if 806 you decide to create a device_type for your root node, make sure it 807 is _not_ "chrp" unless your platform is a pSeries or PAPR compliant 808 one for 64-bit, or a CHRP-type machine for 32-bit as this will 809 matched by the kernel this way. 810 811 Additionally, some recommended properties are: 812 813 - compatible : the board "family" generally finds its way here, 814 for example, if you have 2 board models with a similar layout, 815 that typically get driven by the same platform code in the 816 kernel, you would use a different "model" property but put a 817 value in "compatible". The kernel doesn't directly use that 818 value but it is generally useful. 819 820 The root node is also generally where you add additional properties 821 specific to your board like the serial number if any, that sort of 822 thing. It is recommended that if you add any "custom" property whose 823 name may clash with standard defined ones, you prefix them with your 824 vendor name and a comma. 825 826 b) The /cpus node 827 828 This node is the parent of all individual CPU nodes. It doesn't 829 have any specific requirements, though it's generally good practice 830 to have at least: 831 832 #address-cells = <00000001> 833 #size-cells = <00000000> 834 835 This defines that the "address" for a CPU is a single cell, and has 836 no meaningful size. This is not necessary but the kernel will assume 837 that format when reading the "reg" properties of a CPU node, see 838 below 839 840 c) The /cpus/* nodes 841 842 So under /cpus, you are supposed to create a node for every CPU on 843 the machine. There is no specific restriction on the name of the 844 CPU, though It's common practice to call it PowerPC,<name>. For 845 example, Apple uses PowerPC,G5 while IBM uses PowerPC,970FX. 846 847 Required properties: 848 849 - device_type : has to be "cpu" 850 - reg : This is the physical CPU number, it's a single 32-bit cell 851 and is also used as-is as the unit number for constructing the 852 unit name in the full path. For example, with 2 CPUs, you would 853 have the full path: 854 /cpus/PowerPC,970FX@0 855 /cpus/PowerPC,970FX@1 856 (unit addresses do not require leading zeroes) 857 - d-cache-block-size : one cell, L1 data cache block size in bytes (*) 858 - i-cache-block-size : one cell, L1 instruction cache block size in 859 bytes 860 - d-cache-size : one cell, size of L1 data cache in bytes 861 - i-cache-size : one cell, size of L1 instruction cache in bytes 862 863(*) The cache "block" size is the size on which the cache management 864instructions operate. Historically, this document used the cache 865"line" size here which is incorrect. The kernel will prefer the cache 866block size and will fallback to cache line size for backward 867compatibility. 868 869 Recommended properties: 870 871 - timebase-frequency : a cell indicating the frequency of the 872 timebase in Hz. This is not directly used by the generic code, 873 but you are welcome to copy/paste the pSeries code for setting 874 the kernel timebase/decrementer calibration based on this 875 value. 876 - clock-frequency : a cell indicating the CPU core clock frequency 877 in Hz. A new property will be defined for 64-bit values, but if 878 your frequency is < 4Ghz, one cell is enough. Here as well as 879 for the above, the common code doesn't use that property, but 880 you are welcome to re-use the pSeries or Maple one. A future 881 kernel version might provide a common function for this. 882 - d-cache-line-size : one cell, L1 data cache line size in bytes 883 if different from the block size 884 - i-cache-line-size : one cell, L1 instruction cache line size in 885 bytes if different from the block size 886 887 You are welcome to add any property you find relevant to your board, 888 like some information about the mechanism used to soft-reset the 889 CPUs. For example, Apple puts the GPIO number for CPU soft reset 890 lines in there as a "soft-reset" property since they start secondary 891 CPUs by soft-resetting them. 892 893 894 d) the /memory node(s) 895 896 To define the physical memory layout of your board, you should 897 create one or more memory node(s). You can either create a single 898 node with all memory ranges in its reg property, or you can create 899 several nodes, as you wish. The unit address (@ part) used for the 900 full path is the address of the first range of memory defined by a 901 given node. If you use a single memory node, this will typically be 902 @0. 903 904 Required properties: 905 906 - device_type : has to be "memory" 907 - reg : This property contains all the physical memory ranges of 908 your board. It's a list of addresses/sizes concatenated 909 together, with the number of cells of each defined by the 910 #address-cells and #size-cells of the root node. For example, 911 with both of these properties being 2 like in the example given 912 earlier, a 970 based machine with 6Gb of RAM could typically 913 have a "reg" property here that looks like: 914 915 00000000 00000000 00000000 80000000 916 00000001 00000000 00000001 00000000 917 918 That is a range starting at 0 of 0x80000000 bytes and a range 919 starting at 0x100000000 and of 0x100000000 bytes. You can see 920 that there is no memory covering the IO hole between 2Gb and 921 4Gb. Some vendors prefer splitting those ranges into smaller 922 segments, but the kernel doesn't care. 923 924 e) The /chosen node 925 926 This node is a bit "special". Normally, that's where open firmware 927 puts some variable environment information, like the arguments, or 928 the default input/output devices. 929 930 This specification makes a few of these mandatory, but also defines 931 some linux-specific properties that would be normally constructed by 932 the prom_init() trampoline when booting with an OF client interface, 933 but that you have to provide yourself when using the flattened format. 934 935 Recommended properties: 936 937 - bootargs : This zero-terminated string is passed as the kernel 938 command line 939 - linux,stdout-path : This is the full path to your standard 940 console device if any. Typically, if you have serial devices on 941 your board, you may want to put the full path to the one set as 942 the default console in the firmware here, for the kernel to pick 943 it up as its own default console. If you look at the function 944 set_preferred_console() in arch/ppc64/kernel/setup.c, you'll see 945 that the kernel tries to find out the default console and has 946 knowledge of various types like 8250 serial ports. You may want 947 to extend this function to add your own. 948 949 Note that u-boot creates and fills in the chosen node for platforms 950 that use it. 951 952 (Note: a practice that is now obsolete was to include a property 953 under /chosen called interrupt-controller which had a phandle value 954 that pointed to the main interrupt controller) 955 956 f) the /soc<SOCname> node 957 958 This node is used to represent a system-on-a-chip (SOC) and must be 959 present if the processor is a SOC. The top-level soc node contains 960 information that is global to all devices on the SOC. The node name 961 should contain a unit address for the SOC, which is the base address 962 of the memory-mapped register set for the SOC. The name of an soc 963 node should start with "soc", and the remainder of the name should 964 represent the part number for the soc. For example, the MPC8540's 965 soc node would be called "soc8540". 966 967 Required properties: 968 969 - device_type : Should be "soc" 970 - ranges : Should be defined as specified in 1) to describe the 971 translation of SOC addresses for memory mapped SOC registers. 972 - bus-frequency: Contains the bus frequency for the SOC node. 973 Typically, the value of this field is filled in by the boot 974 loader. 975 976 977 Recommended properties: 978 979 - reg : This property defines the address and size of the 980 memory-mapped registers that are used for the SOC node itself. 981 It does not include the child device registers - these will be 982 defined inside each child node. The address specified in the 983 "reg" property should match the unit address of the SOC node. 984 - #address-cells : Address representation for "soc" devices. The 985 format of this field may vary depending on whether or not the 986 device registers are memory mapped. For memory mapped 987 registers, this field represents the number of cells needed to 988 represent the address of the registers. For SOCs that do not 989 use MMIO, a special address format should be defined that 990 contains enough cells to represent the required information. 991 See 1) above for more details on defining #address-cells. 992 - #size-cells : Size representation for "soc" devices 993 - #interrupt-cells : Defines the width of cells used to represent 994 interrupts. Typically this value is <2>, which includes a 995 32-bit number that represents the interrupt number, and a 996 32-bit number that represents the interrupt sense and level. 997 This field is only needed if the SOC contains an interrupt 998 controller. 999 1000 The SOC node may contain child nodes for each SOC device that the 1001 platform uses. Nodes should not be created for devices which exist 1002 on the SOC but are not used by a particular platform. See chapter VI 1003 for more information on how to specify devices that are part of a SOC. 1004 1005 Example SOC node for the MPC8540: 1006 1007 soc8540@e0000000 { 1008 #address-cells = <1>; 1009 #size-cells = <1>; 1010 #interrupt-cells = <2>; 1011 device_type = "soc"; 1012 ranges = <00000000 e0000000 00100000> 1013 reg = <e0000000 00003000>; 1014 bus-frequency = <0>; 1015 } 1016 1017 1018 1019IV - "dtc", the device tree compiler 1020==================================== 1021 1022 1023dtc source code can be found at 1024<http://git.jdl.com/gitweb/?p=dtc.git> 1025 1026WARNING: This version is still in early development stage; the 1027resulting device-tree "blobs" have not yet been validated with the 1028kernel. The current generated bloc lacks a useful reserve map (it will 1029be fixed to generate an empty one, it's up to the bootloader to fill 1030it up) among others. The error handling needs work, bugs are lurking, 1031etc... 1032 1033dtc basically takes a device-tree in a given format and outputs a 1034device-tree in another format. The currently supported formats are: 1035 1036 Input formats: 1037 ------------- 1038 1039 - "dtb": "blob" format, that is a flattened device-tree block 1040 with 1041 header all in a binary blob. 1042 - "dts": "source" format. This is a text file containing a 1043 "source" for a device-tree. The format is defined later in this 1044 chapter. 1045 - "fs" format. This is a representation equivalent to the 1046 output of /proc/device-tree, that is nodes are directories and 1047 properties are files 1048 1049 Output formats: 1050 --------------- 1051 1052 - "dtb": "blob" format 1053 - "dts": "source" format 1054 - "asm": assembly language file. This is a file that can be 1055 sourced by gas to generate a device-tree "blob". That file can 1056 then simply be added to your Makefile. Additionally, the 1057 assembly file exports some symbols that can be used. 1058 1059 1060The syntax of the dtc tool is 1061 1062 dtc [-I <input-format>] [-O <output-format>] 1063 [-o output-filename] [-V output_version] input_filename 1064 1065 1066The "output_version" defines what version of the "blob" format will be 1067generated. Supported versions are 1,2,3 and 16. The default is 1068currently version 3 but that may change in the future to version 16. 1069 1070Additionally, dtc performs various sanity checks on the tree, like the 1071uniqueness of linux, phandle properties, validity of strings, etc... 1072 1073The format of the .dts "source" file is "C" like, supports C and C++ 1074style comments. 1075 1076/ { 1077} 1078 1079The above is the "device-tree" definition. It's the only statement 1080supported currently at the toplevel. 1081 1082/ { 1083 property1 = "string_value"; /* define a property containing a 0 1084 * terminated string 1085 */ 1086 1087 property2 = <1234abcd>; /* define a property containing a 1088 * numerical 32-bit value (hexadecimal) 1089 */ 1090 1091 property3 = <12345678 12345678 deadbeef>; 1092 /* define a property containing 3 1093 * numerical 32-bit values (cells) in 1094 * hexadecimal 1095 */ 1096 property4 = [0a 0b 0c 0d de ea ad be ef]; 1097 /* define a property whose content is 1098 * an arbitrary array of bytes 1099 */ 1100 1101 childnode@addresss { /* define a child node named "childnode" 1102 * whose unit name is "childnode at 1103 * address" 1104 */ 1105 1106 childprop = "hello\n"; /* define a property "childprop" of 1107 * childnode (in this case, a string) 1108 */ 1109 }; 1110}; 1111 1112Nodes can contain other nodes etc... thus defining the hierarchical 1113structure of the tree. 1114 1115Strings support common escape sequences from C: "\n", "\t", "\r", 1116"\(octal value)", "\x(hex value)". 1117 1118It is also suggested that you pipe your source file through cpp (gcc 1119preprocessor) so you can use #include's, #define for constants, etc... 1120 1121Finally, various options are planned but not yet implemented, like 1122automatic generation of phandles, labels (exported to the asm file so 1123you can point to a property content and change it easily from whatever 1124you link the device-tree with), label or path instead of numeric value 1125in some cells to "point" to a node (replaced by a phandle at compile 1126time), export of reserve map address to the asm file, ability to 1127specify reserve map content at compile time, etc... 1128 1129We may provide a .h include file with common definitions of that 1130proves useful for some properties (like building PCI properties or 1131interrupt maps) though it may be better to add a notion of struct 1132definitions to the compiler... 1133 1134 1135V - Recommendations for a bootloader 1136==================================== 1137 1138 1139Here are some various ideas/recommendations that have been proposed 1140while all this has been defined and implemented. 1141 1142 - The bootloader may want to be able to use the device-tree itself 1143 and may want to manipulate it (to add/edit some properties, 1144 like physical memory size or kernel arguments). At this point, 2 1145 choices can be made. Either the bootloader works directly on the 1146 flattened format, or the bootloader has its own internal tree 1147 representation with pointers (similar to the kernel one) and 1148 re-flattens the tree when booting the kernel. The former is a bit 1149 more difficult to edit/modify, the later requires probably a bit 1150 more code to handle the tree structure. Note that the structure 1151 format has been designed so it's relatively easy to "insert" 1152 properties or nodes or delete them by just memmoving things 1153 around. It contains no internal offsets or pointers for this 1154 purpose. 1155 1156 - An example of code for iterating nodes & retrieving properties 1157 directly from the flattened tree format can be found in the kernel 1158 file arch/ppc64/kernel/prom.c, look at scan_flat_dt() function, 1159 its usage in early_init_devtree(), and the corresponding various 1160 early_init_dt_scan_*() callbacks. That code can be re-used in a 1161 GPL bootloader, and as the author of that code, I would be happy 1162 to discuss possible free licensing to any vendor who wishes to 1163 integrate all or part of this code into a non-GPL bootloader. 1164 1165 1166 1167VI - System-on-a-chip devices and nodes 1168======================================= 1169 1170Many companies are now starting to develop system-on-a-chip 1171processors, where the processor core (CPU) and many peripheral devices 1172exist on a single piece of silicon. For these SOCs, an SOC node 1173should be used that defines child nodes for the devices that make 1174up the SOC. While platforms are not required to use this model in 1175order to boot the kernel, it is highly encouraged that all SOC 1176implementations define as complete a flat-device-tree as possible to 1177describe the devices on the SOC. This will allow for the 1178genericization of much of the kernel code. 1179 1180 11811) Defining child nodes of an SOC 1182--------------------------------- 1183 1184Each device that is part of an SOC may have its own node entry inside 1185the SOC node. For each device that is included in the SOC, the unit 1186address property represents the address offset for this device's 1187memory-mapped registers in the parent's address space. The parent's 1188address space is defined by the "ranges" property in the top-level soc 1189node. The "reg" property for each node that exists directly under the 1190SOC node should contain the address mapping from the child address space 1191to the parent SOC address space and the size of the device's 1192memory-mapped register file. 1193 1194For many devices that may exist inside an SOC, there are predefined 1195specifications for the format of the device tree node. All SOC child 1196nodes should follow these specifications, except where noted in this 1197document. 1198 1199See appendix A for an example partial SOC node definition for the 1200MPC8540. 1201 1202 12032) Representing devices without a current OF specification 1204---------------------------------------------------------- 1205 1206Currently, there are many devices on SOCs that do not have a standard 1207representation pre-defined as part of the open firmware 1208specifications, mainly because the boards that contain these SOCs are 1209not currently booted using open firmware. This section contains 1210descriptions for the SOC devices for which new nodes have been 1211defined; this list will expand as more and more SOC-containing 1212platforms are moved over to use the flattened-device-tree model. 1213 1214VII - Specifying interrupt information for devices 1215=================================================== 1216 1217The device tree represents the busses and devices of a hardware 1218system in a form similar to the physical bus topology of the 1219hardware. 1220 1221In addition, a logical 'interrupt tree' exists which represents the 1222hierarchy and routing of interrupts in the hardware. 1223 1224The interrupt tree model is fully described in the 1225document "Open Firmware Recommended Practice: Interrupt 1226Mapping Version 0.9". The document is available at: 1227<http://playground.sun.com/1275/practice>. 1228 12291) interrupts property 1230---------------------- 1231 1232Devices that generate interrupts to a single interrupt controller 1233should use the conventional OF representation described in the 1234OF interrupt mapping documentation. 1235 1236Each device which generates interrupts must have an 'interrupt' 1237property. The interrupt property value is an arbitrary number of 1238of 'interrupt specifier' values which describe the interrupt or 1239interrupts for the device. 1240 1241The encoding of an interrupt specifier is determined by the 1242interrupt domain in which the device is located in the 1243interrupt tree. The root of an interrupt domain specifies in 1244its #interrupt-cells property the number of 32-bit cells 1245required to encode an interrupt specifier. See the OF interrupt 1246mapping documentation for a detailed description of domains. 1247 1248For example, the binding for the OpenPIC interrupt controller 1249specifies an #interrupt-cells value of 2 to encode the interrupt 1250number and level/sense information. All interrupt children in an 1251OpenPIC interrupt domain use 2 cells per interrupt in their interrupts 1252property. 1253 1254The PCI bus binding specifies a #interrupt-cell value of 1 to encode 1255which interrupt pin (INTA,INTB,INTC,INTD) is used. 1256 12572) interrupt-parent property 1258---------------------------- 1259 1260The interrupt-parent property is specified to define an explicit 1261link between a device node and its interrupt parent in 1262the interrupt tree. The value of interrupt-parent is the 1263phandle of the parent node. 1264 1265If the interrupt-parent property is not defined for a node, its 1266interrupt parent is assumed to be an ancestor in the node's 1267_device tree_ hierarchy. 1268 12693) OpenPIC Interrupt Controllers 1270-------------------------------- 1271 1272OpenPIC interrupt controllers require 2 cells to encode 1273interrupt information. The first cell defines the interrupt 1274number. The second cell defines the sense and level 1275information. 1276 1277Sense and level information should be encoded as follows: 1278 1279 0 = low to high edge sensitive type enabled 1280 1 = active low level sensitive type enabled 1281 2 = active high level sensitive type enabled 1282 3 = high to low edge sensitive type enabled 1283 12844) ISA Interrupt Controllers 1285---------------------------- 1286 1287ISA PIC interrupt controllers require 2 cells to encode 1288interrupt information. The first cell defines the interrupt 1289number. The second cell defines the sense and level 1290information. 1291 1292ISA PIC interrupt controllers should adhere to the ISA PIC 1293encodings listed below: 1294 1295 0 = active low level sensitive type enabled 1296 1 = active high level sensitive type enabled 1297 2 = high to low edge sensitive type enabled 1298 3 = low to high edge sensitive type enabled 1299 1300VIII - Specifying Device Power Management Information (sleep property) 1301=================================================================== 1302 1303Devices on SOCs often have mechanisms for placing devices into low-power 1304states that are decoupled from the devices' own register blocks. Sometimes, 1305this information is more complicated than a cell-index property can 1306reasonably describe. Thus, each device controlled in such a manner 1307may contain a "sleep" property which describes these connections. 1308 1309The sleep property consists of one or more sleep resources, each of 1310which consists of a phandle to a sleep controller, followed by a 1311controller-specific sleep specifier of zero or more cells. 1312 1313The semantics of what type of low power modes are possible are defined 1314by the sleep controller. Some examples of the types of low power modes 1315that may be supported are: 1316 1317 - Dynamic: The device may be disabled or enabled at any time. 1318 - System Suspend: The device may request to be disabled or remain 1319 awake during system suspend, but will not be disabled until then. 1320 - Permanent: The device is disabled permanently (until the next hard 1321 reset). 1322 1323Some devices may share a clock domain with each other, such that they should 1324only be suspended when none of the devices are in use. Where reasonable, 1325such nodes should be placed on a virtual bus, where the bus has the sleep 1326property. If the clock domain is shared among devices that cannot be 1327reasonably grouped in this manner, then create a virtual sleep controller 1328(similar to an interrupt nexus, except that defining a standardized 1329sleep-map should wait until its necessity is demonstrated). 1330 1331Appendix A - Sample SOC node for MPC8540 1332======================================== 1333 1334 soc@e0000000 { 1335 #address-cells = <1>; 1336 #size-cells = <1>; 1337 compatible = "fsl,mpc8540-ccsr", "simple-bus"; 1338 device_type = "soc"; 1339 ranges = <0x00000000 0xe0000000 0x00100000> 1340 bus-frequency = <0>; 1341 interrupt-parent = <&pic>; 1342 1343 ethernet@24000 { 1344 #address-cells = <1>; 1345 #size-cells = <1>; 1346 device_type = "network"; 1347 model = "TSEC"; 1348 compatible = "gianfar", "simple-bus"; 1349 reg = <0x24000 0x1000>; 1350 local-mac-address = [ 00 E0 0C 00 73 00 ]; 1351 interrupts = <29 2 30 2 34 2>; 1352 phy-handle = <&phy0>; 1353 sleep = <&pmc 00000080>; 1354 ranges; 1355 1356 mdio@24520 { 1357 reg = <0x24520 0x20>; 1358 compatible = "fsl,gianfar-mdio"; 1359 1360 phy0: ethernet-phy@0 { 1361 interrupts = <5 1>; 1362 reg = <0>; 1363 device_type = "ethernet-phy"; 1364 }; 1365 1366 phy1: ethernet-phy@1 { 1367 interrupts = <5 1>; 1368 reg = <1>; 1369 device_type = "ethernet-phy"; 1370 }; 1371 1372 phy3: ethernet-phy@3 { 1373 interrupts = <7 1>; 1374 reg = <3>; 1375 device_type = "ethernet-phy"; 1376 }; 1377 }; 1378 }; 1379 1380 ethernet@25000 { 1381 device_type = "network"; 1382 model = "TSEC"; 1383 compatible = "gianfar"; 1384 reg = <0x25000 0x1000>; 1385 local-mac-address = [ 00 E0 0C 00 73 01 ]; 1386 interrupts = <13 2 14 2 18 2>; 1387 phy-handle = <&phy1>; 1388 sleep = <&pmc 00000040>; 1389 }; 1390 1391 ethernet@26000 { 1392 device_type = "network"; 1393 model = "FEC"; 1394 compatible = "gianfar"; 1395 reg = <0x26000 0x1000>; 1396 local-mac-address = [ 00 E0 0C 00 73 02 ]; 1397 interrupts = <41 2>; 1398 phy-handle = <&phy3>; 1399 sleep = <&pmc 00000020>; 1400 }; 1401 1402 serial@4500 { 1403 #address-cells = <1>; 1404 #size-cells = <1>; 1405 compatible = "fsl,mpc8540-duart", "simple-bus"; 1406 sleep = <&pmc 00000002>; 1407 ranges; 1408 1409 serial@4500 { 1410 device_type = "serial"; 1411 compatible = "ns16550"; 1412 reg = <0x4500 0x100>; 1413 clock-frequency = <0>; 1414 interrupts = <42 2>; 1415 }; 1416 1417 serial@4600 { 1418 device_type = "serial"; 1419 compatible = "ns16550"; 1420 reg = <0x4600 0x100>; 1421 clock-frequency = <0>; 1422 interrupts = <42 2>; 1423 }; 1424 }; 1425 1426 pic: pic@40000 { 1427 interrupt-controller; 1428 #address-cells = <0>; 1429 #interrupt-cells = <2>; 1430 reg = <0x40000 0x40000>; 1431 compatible = "chrp,open-pic"; 1432 device_type = "open-pic"; 1433 }; 1434 1435 i2c@3000 { 1436 interrupts = <43 2>; 1437 reg = <0x3000 0x100>; 1438 compatible = "fsl-i2c"; 1439 dfsrr; 1440 sleep = <&pmc 00000004>; 1441 }; 1442 1443 pmc: power@e0070 { 1444 compatible = "fsl,mpc8540-pmc", "fsl,mpc8548-pmc"; 1445 reg = <0xe0070 0x20>; 1446 }; 1447 }; 1448