1.. SPDX-License-Identifier: GPL-2.0+
2
3M68K / ColdFire
4===============
5
6History
7-------
8* November 02, 2017	Angelo Dureghello <angelo@kernel-space.org>
9* August   08, 2005	Jens Scharsig <esw@bus-elektronik.de>
10  MCF5282 implementation without preloader
11* January  12, 2004	<josef.baumgartner@telex.de>
12
13This file contains status information for the port of U-Boot to the
14Motorola ColdFire series of CPUs.
15
16Overview
17--------
18
19The ColdFire instruction set is "assembly source" compatible but an evolution
20of the original 68000 instruction set. Some not much used instructions has
21been removed. The instructions are only 16, 32, or 48 bits long, a
22simplification compared to the 68000 series.
23
24Bernhard Kuhn ported U-Boot 0.4.0 to the Motorola ColdFire architecture.
25The patches of Bernhard support the MCF5272 and MCF5282. A great disadvantage
26of these patches was that they needed a pre-bootloader to start U-Boot.
27Because of this, a new port was created which no longer needs a first stage
28booter.
29
30Thanks mainly to Freescale but also to several other contributors, U-Boot now
31supports nearly the entire range of ColdFire processors and their related
32development boards.
33
34
35Supported CPU families
36----------------------
37
38Please "make menuconfig" and select "m68k" or check arch/m68k/cpu to see the
39currently supported processor and families.
40
41
42Supported boards
43----------------
44
45U-Boot supports actually more than 40 ColdFire based boards.
46Board configuration can be done trough include/configs/<boardname>.h but the
47current recommended method is to use the new and more friendly approach as
48the "make menuconfig" way, very similar to the Linux way.
49
50To know details as memory map, build targets, default setup, etc, of a
51specific board please check:
52
53* include/configs/<boardname>.h
54
55and/or
56
57* configs/<boardname>_defconfig
58
59It is possible to build all ColdFire boards in a single command-line command,
60from u-boot root directory, as::
61
62   ./tools/buildman/buildman m68k
63
64Build U-Boot for a specific board
65^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
66
67A bash script similar to the one below may be used:
68
69.. code-block:: shell
70
71   #!/bin/bash
72
73   export CROSS_COMPILE=/opt/toolchains/m68k/gcc-4.9.0-nolibc/bin/m68k-linux-
74
75   board=M5249EVB
76
77   make distclean
78   make ${board}_defconfig
79   make KBUILD_VERBOSE=1
80
81
82Adopted toolchains
83------------------
84
85Please check:
86https://www.denx.de/wiki/U-Boot/ColdFireNotes
87
88
89ColdFire specific configuration options/settings
90------------------------------------------------
91
92Configuration to use a pre-loader
93^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
94
95If U-Boot should be loaded to RAM and started by a pre-loader
96CONFIG_MONITOR_IS_IN_RAM must be enabled. If it is enabled the
97initial vector table and basic processor initialization will not
98be compiled in. The start address of U-Boot must be adjusted in
99the boards defconfig file (CONFIG_SYS_MONITOR_BASE) and Makefile
100(CONFIG_TEXT_BASE) to the load address.
101
102ColdFire CPU specific options/settings
103^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
104
105To specify a CPU model, some defines shoudl be used, i.e.:
106
107CONFIG_MCF52x2:
108  defined for all MCF52x2 CPUs
109CONFIG_M5272:
110  defined for all Motorola MCF5272 CPUs
111
112Other options, generally set inside include/configs/<boardname>.h, they may
113apply to one or more cpu for the ColdFire family:
114
115CFG_SYS_MBAR:
116  defines the base address of the MCF5272 configuration registers
117CFG_SYS_SCR:
118  defines the contents of the System Configuration Register
119CFG_SYS_SPR:
120  defines the contents of the System Protection Register
121CFG_SYS_MFD:
122  defines the PLL Multiplication Factor Divider
123  (see table 9-4 of MCF user manual)
124CFG_SYS_RFD:
125  defines the PLL Reduce Frequency Devider
126  (see table 9-4 of MCF user manual)
127CONFIG_SYS_CSx_BASE:
128  defines the base address of chip select x
129CONFIG_SYS_CSx_SIZE:
130  defines the memory size (address range) of chip select x
131CONFIG_SYS_CSx_WIDTH:
132  defines the bus with of chip select x
133CONFIG_SYS_CSx_MASK:
134  defines the mask for the related chip select x
135CONFIG_SYS_CSx_RO:
136  if set to 0 chip select x is read/write else chip select is read only
137CONFIG_SYS_CSx_WS:
138  defines the number of wait states  of chip select x
139CFG_SYS_CACHE_ICACR:
140  cache-related registers config
141CFG_SYS_CACHE_DCACR:
142  cache-related registers config
143CONFIG_SYS_CACHE_ACRX:
144  cache-related registers config
145CFG_SYS_SDRAM_BASE:
146  SDRAM config for SDRAM controller-specific registers
147CFG_SYS_SDRAM_SIZE:
148  SDRAM config for SDRAM controller-specific registers
149CFG_SYS_SDRAM_BASEX:
150  SDRAM config for SDRAM controller-specific registers
151CFG_SYS_SDRAM_CFG1:
152  SDRAM config for SDRAM controller-specific registers
153CFG_SYS_SDRAM_CFG2:
154  SDRAM config for SDRAM controller-specific registers
155CFG_SYS_SDRAM_CTRL:
156  SDRAM config for SDRAM controller-specific registers
157CFG_SYS_SDRAM_MODE:
158  SDRAM config for SDRAM controller-specific registers
159CFG_SYS_SDRAM_EMOD:
160  SDRAM config for SDRAM controller-specific registers, please
161  see arch/m68k/cpu/<specific_cpu>/start.S files to see how
162  these options are used.
163CONFIG_MCFUART:
164  defines enabling of ColdFire UART driver
165CFG_SYS_UART_PORT:
166  defines the UART port to be used (only a single UART can be actually enabled)
167CFG_SYS_SBFHDR_SIZE:
168  size of the prepended SBF header, if any
169