1/* 2 * Rescue code, made to reside at the beginning of the 3 * flash-memory. when it starts, it checks a partition 4 * table at the first sector after the rescue sector. 5 * the partition table was generated by the product builder 6 * script and contains offsets, lengths, types and checksums 7 * for each partition that this code should check. 8 * 9 * If any of the checksums fail, we assume the flash is so 10 * corrupt that we cant use it to boot into the ftp flash 11 * loader, and instead we initialize the serial port to 12 * receive a flash-loader and new flash image. we dont include 13 * any flash code here, but just accept a certain amount of 14 * bytes from the serial port and jump into it. the downloaded 15 * code is put in the cache. 16 * 17 * The partitiontable is designed so that it is transparent to 18 * code execution - it has a relative branch opcode in the 19 * beginning that jumps over it. each entry contains extra 20 * data so we can add stuff later. 21 * 22 * Partition table format: 23 * 24 * Code transparency: 25 * 26 * 2 bytes [opcode 'nop'] 27 * 2 bytes [opcode 'di'] 28 * 4 bytes [opcode 'ba <offset>', 8-bit or 16-bit version] 29 * 2 bytes [opcode 'nop', delay slot] 30 * 31 * Table validation (at +10): 32 * 33 * 2 bytes [magic/version word for partitiontable - 0xef, 0xbe] 34 * 2 bytes [length of all entries plus the end marker] 35 * 4 bytes [checksum for the partitiontable itself] 36 * 37 * Entries, each with the following format, last has offset -1: 38 * 39 * 4 bytes [offset in bytes, from start of flash] 40 * 4 bytes [length in bytes of partition] 41 * 4 bytes [checksum, simple longword sum] 42 * 2 bytes [partition type] 43 * 2 bytes [flags, only bit 0 used, ro/rw = 1/0] 44 * 16 bytes [reserved for future use] 45 * 46 * End marker 47 * 48 * 4 bytes [-1] 49 * 50 * 10 bytes [0, padding] 51 * 52 * Bit 0 in flags signifies RW or RO. The rescue code only bothers 53 * to check the checksum for RO partitions, since the others will 54 * change their data without updating the checksums. A 1 in bit 0 55 * means RO, 0 means RW. That way, it is possible to set a partition 56 * in RO mode initially, and later mark it as RW, since you can always 57 * write 0's to the flash. 58 * 59 * During the wait for serial input, the status LED will flash so the 60 * user knows something went wrong. 61 * 62 * Copyright (C) 1999-2007 Axis Communications AB 63 */ 64 65#ifdef CONFIG_ETRAX_AXISFLASHMAP 66 67#define ASSEMBLER_MACROS_ONLY 68#include <arch/sv_addr_ag.h> 69 70 ;; The partitiontable is looked for at the first sector after the boot 71 ;; sector. Sector size is 65536 bytes in all flashes we use. 72 73#define PTABLE_START CONFIG_ETRAX_PTABLE_SECTOR 74#define PTABLE_MAGIC 0xbeef 75 76 ;; The normal Etrax100 on-chip boot ROM does serial boot at 0x380000f0. 77 ;; That is not where we put our downloaded serial boot-code. 78 ;; The length is enough for downloading code that loads the rest 79 ;; of itself (after having setup the DRAM etc). 80 ;; It is the same length as the on-chip ROM loads, so the same 81 ;; host loader can be used to load a rescued product as well as 82 ;; one booted through the Etrax serial boot code. 83 84#define CODE_START 0x40000000 85#define CODE_LENGTH 784 86 87#ifdef CONFIG_ETRAX_RESCUE_SER0 88#define SERXOFF R_SERIAL0_XOFF 89#define SERBAUD R_SERIAL0_BAUD 90#define SERRECC R_SERIAL0_REC_CTRL 91#define SERRDAT R_SERIAL0_REC_DATA 92#define SERSTAT R_SERIAL0_STATUS 93#endif 94#ifdef CONFIG_ETRAX_RESCUE_SER1 95#define SERXOFF R_SERIAL1_XOFF 96#define SERBAUD R_SERIAL1_BAUD 97#define SERRECC R_SERIAL1_REC_CTRL 98#define SERRDAT R_SERIAL1_REC_DATA 99#define SERSTAT R_SERIAL1_STATUS 100#endif 101#ifdef CONFIG_ETRAX_RESCUE_SER2 102#define SERXOFF R_SERIAL2_XOFF 103#define SERBAUD R_SERIAL2_BAUD 104#define SERRECC R_SERIAL2_REC_CTRL 105#define SERRDAT R_SERIAL2_REC_DATA 106#define SERSTAT R_SERIAL2_STATUS 107#endif 108#ifdef CONFIG_ETRAX_RESCUE_SER3 109#define SERXOFF R_SERIAL3_XOFF 110#define SERBAUD R_SERIAL3_BAUD 111#define SERRECC R_SERIAL3_REC_CTRL 112#define SERRDAT R_SERIAL3_REC_DATA 113#define SERSTAT R_SERIAL3_STATUS 114#endif 115 116#define NOP_DI 0xf025050f 117#define RAM_INIT_MAGIC 0x56902387 118 119 .text 120 121 ;; This is the entry point of the rescue code 122 ;; 0x80000000 if loaded in flash (as it should be) 123 ;; Since etrax actually starts at address 2 when booting from flash, we 124 ;; put a nop (2 bytes) here first so we dont accidentally skip the di 125 126 nop 127 di 128 129 jump in_cache ; enter cached area instead 130in_cache: 131 132 133 ;; First put a jump test to give a possibility of upgrading the 134 ;; rescue code without erasing/reflashing the sector. 135 ;; We put a longword of -1 here and if it is not -1, we jump using 136 ;; the value as jump target. Since we can always change 1's to 0's 137 ;; without erasing the sector, it is possible to add new 138 ;; code after this and altering the jumptarget in an upgrade. 139 140jtcd: move.d [jumptarget], $r0 141 cmp.d 0xffffffff, $r0 142 beq no_newjump 143 nop 144 145 jump [$r0] 146 147jumptarget: 148 .dword 0xffffffff ; can be overwritten later to insert new code 149 150no_newjump: 151#ifdef CONFIG_ETRAX_ETHERNET 152 ;; Start MII clock to make sure it is running when tranceiver is reset 153 move.d 0x3, $r0 ; enable = on, phy = mii_clk 154 move.d $r0, [R_NETWORK_GEN_CONFIG] 155#endif 156 157 ;; We need to setup the bus registers before we start using the DRAM 158#include "../../../arch-v10/lib/dram_init.S" 159 160 ;; we now should go through the checksum-table and check the listed 161 ;; partitions for errors. 162 163 move.d PTABLE_START, $r3 164 move.d [$r3], $r0 165 cmp.d NOP_DI, $r0 ; make sure the nop/di is there... 166 bne do_rescue 167 nop 168 169 ;; skip the code transparency block (10 bytes). 170 171 addq 10, $r3 172 173 ;; check for correct magic 174 175 move.w [$r3+], $r0 176 cmp.w PTABLE_MAGIC, $r0 177 bne do_rescue ; didn't recognize - trig rescue 178 nop 179 180 ;; check for correct ptable checksum 181 182 movu.w [$r3+], $r2 ; ptable length 183 move.d $r2, $r8 ; save for later, length of total ptable 184 addq 28, $r8 ; account for the rest 185 move.d [$r3+], $r4 ; ptable checksum 186 move.d $r3, $r1 187 jsr checksum ; r1 source, r2 length, returns in r0 188 189 cmp.d $r0, $r4 190 bne do_rescue ; didn't match - trig rescue 191 nop 192 193 ;; ptable is ok. validate each entry. 194 195 moveq -1, $r7 196 197ploop: move.d [$r3+], $r1 ; partition offset (from ptable start) 198 bne notfirst ; check if it is the partition containing ptable 199 nop ; yes.. 200 move.d $r8, $r1 ; for its checksum check, skip the ptable 201 move.d [$r3+], $r2 ; partition length 202 sub.d $r8, $r2 ; minus the ptable length 203 ba bosse 204 nop 205notfirst: 206 cmp.d -1, $r1 ; the end of the ptable ? 207 beq flash_ok ; if so, the flash is validated 208 move.d [$r3+], $r2 ; partition length 209bosse: move.d [$r3+], $r5 ; checksum 210 move.d [$r3+], $r4 ; type and flags 211 addq 16, $r3 ; skip the reserved bytes 212 btstq 16, $r4 ; check ro flag 213 bpl ploop ; rw partition, skip validation 214 nop 215 btstq 17, $r4 ; check bootable flag 216 bpl 1f 217 nop 218 move.d $r1, $r7 ; remember boot partition offset 2191: 220 add.d PTABLE_START, $r1 221 222 jsr checksum ; checksum the partition 223 224 cmp.d $r0, $r5 225 beq ploop ; checksums matched, go to next entry 226 nop 227 228 ;; otherwise fall through to the rescue code. 229 230do_rescue: 231 ;; setup port PA and PB default initial directions and data 232 ;; (so we can flash LEDs, and so that DTR and others are set) 233 234 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0 235 move.b $r0, [R_PORT_PA_DIR] 236 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0 237 move.b $r0, [R_PORT_PA_DATA] 238 239 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0 240 move.b $r0, [R_PORT_PB_DIR] 241 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0 242 move.b $r0, [R_PORT_PB_DATA] 243 244 ;; setup the serial port at 115200 baud 245 246 moveq 0, $r0 247 move.d $r0, [SERXOFF] 248 249 move.b 0x99, $r0 250 move.b $r0, [SERBAUD] ; 115.2kbaud for both transmit and receive 251 252 move.b 0x40, $r0 ; rec enable 253 move.b $r0, [SERRECC] 254 255 moveq 0, $r1 ; "timer" to clock out a LED red flash 256 move.d CODE_START, $r3 ; destination counter 257 movu.w CODE_LENGTH, $r4; length 258 259wait_ser: 260 addq 1, $r1 261#ifndef CONFIG_ETRAX_NO_LEDS 262#ifdef CONFIG_ETRAX_PA_LEDS 263 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2 264#endif 265#ifdef CONFIG_ETRAX_PB_LEDS 266 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2 267#endif 268 move.d (1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0 269 btstq 16, $r1 270 bpl 1f 271 nop 272 or.d $r0, $r2 ; set bit 273 ba 2f 274 nop 2751: not $r0 ; clear bit 276 and.d $r0, $r2 2772: 278#ifdef CONFIG_ETRAX_PA_LEDS 279 move.b $r2, [R_PORT_PA_DATA] 280#endif 281#ifdef CONFIG_ETRAX_PB_LEDS 282 move.b $r2, [R_PORT_PB_DATA] 283#endif 284#ifdef CONFIG_ETRAX_90000000_LEDS 285 move.b $r2, [0x90000000] 286#endif 287#endif 288 289 ;; check if we got something on the serial port 290 291 move.b [SERSTAT], $r0 292 btstq 0, $r0 ; data_avail 293 bpl wait_ser 294 nop 295 296 ;; got something - copy the byte and loop 297 298 move.b [SERRDAT], $r0 299 move.b $r0, [$r3+] 300 301 subq 1, $r4 ; decrease length 302 bne wait_ser 303 nop 304 305 ;; jump into downloaded code 306 307 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is 308 ; initialized 309 jump CODE_START 310 311flash_ok: 312 ;; check r7, which contains either -1 or the partition to boot from 313 314 cmp.d -1, $r7 315 bne 1f 316 nop 317 move.d PTABLE_START, $r7; otherwise use the ptable start 3181: 319 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is 320 ; initialized 321 jump $r7 ; boot! 322 323 324 ;; Helper subroutines 325 326 ;; Will checksum by simple addition 327 ;; r1 - source 328 ;; r2 - length in bytes 329 ;; result will be in r0 330checksum: 331 moveq 0, $r0 332 moveq CONFIG_ETRAX_FLASH1_SIZE, $r6 333 334 ;; If the first physical flash memory is exceeded wrap to the 335 ;; second one 336 btstq 26, $r1 ; Are we addressing first flash? 337 bpl 1f 338 nop 339 clear.d $r6 340 3411: test.d $r6 ; 0 = no wrapping 342 beq 2f 343 nop 344 lslq 20, $r6 ; Convert MB to bytes 345 sub.d $r1, $r6 346 3472: addu.b [$r1+], $r0 348 subq 1, $r6 ; Flash memory left 349 beq 3f 350 subq 1, $r2 ; Length left 351 bne 2b 352 nop 353 ret 354 nop 355 3563: move.d MEM_CSE1_START, $r1 ; wrap to second flash 357 ba 2b 358 nop 359 360#endif 361