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, 2000, 2001, 2002, 2003 Axis Communications AB 63 */ 64 65#include <linux/config.h> 66#define ASSEMBLER_MACROS_ONLY 67#include <asm/sv_addr_ag.h> 68 69 ;; The partitiontable is looked for at the first sector after the boot 70 ;; sector. Sector size is 65536 bytes in all flashes we use. 71 72#define PTABLE_START CONFIG_ETRAX_PTABLE_SECTOR 73#define PTABLE_MAGIC 0xbeef 74 75 ;; The normal Etrax100 on-chip boot ROM does serial boot at 0x380000f0. 76 ;; That is not where we put our downloaded serial boot-code. The length is 77 ;; enough for downloading code that loads the rest of itself (after 78 ;; having setup the DRAM etc). It is the same length as the on-chip 79 ;; ROM loads, so the same host loader can be used to load a rescued 80 ;; product as well as one booted through the Etrax serial boot code. 81 82#define CODE_START 0x40000000 83#define CODE_LENGTH 784 84 85#ifdef CONFIG_ETRAX_RESCUE_SER0 86#define SERXOFF R_SERIAL0_XOFF 87#define SERBAUD R_SERIAL0_BAUD 88#define SERRECC R_SERIAL0_REC_CTRL 89#define SERRDAT R_SERIAL0_REC_DATA 90#define SERSTAT R_SERIAL0_STATUS 91#endif 92#ifdef CONFIG_ETRAX_RESCUE_SER1 93#define SERXOFF R_SERIAL1_XOFF 94#define SERBAUD R_SERIAL1_BAUD 95#define SERRECC R_SERIAL1_REC_CTRL 96#define SERRDAT R_SERIAL1_REC_DATA 97#define SERSTAT R_SERIAL1_STATUS 98#endif 99#ifdef CONFIG_ETRAX_RESCUE_SER2 100#define SERXOFF R_SERIAL2_XOFF 101#define SERBAUD R_SERIAL2_BAUD 102#define SERRECC R_SERIAL2_REC_CTRL 103#define SERRDAT R_SERIAL2_REC_DATA 104#define SERSTAT R_SERIAL2_STATUS 105#endif 106#ifdef CONFIG_ETRAX_RESCUE_SER3 107#define SERXOFF R_SERIAL3_XOFF 108#define SERBAUD R_SERIAL3_BAUD 109#define SERRECC R_SERIAL3_REC_CTRL 110#define SERRDAT R_SERIAL3_REC_DATA 111#define SERSTAT R_SERIAL3_STATUS 112#endif 113 114#define NOP_DI 0xf025050f 115#define RAM_INIT_MAGIC 0x56902387 116 117 .text 118 119 ;; This is the entry point of the rescue code 120 ;; 0x80000000 if loaded in flash (as it should be) 121 ;; since etrax actually starts at address 2 when booting from flash, we 122 ;; put a nop (2 bytes) here first so we dont accidentally skip the di 123 124 nop 125 di 126 127 jump in_cache ; enter cached area instead 128in_cache: 129 130 ;; first put a jump test to give a possibility of upgrading the rescue code 131 ;; without erasing/reflashing the sector. we put a longword of -1 here and if 132 ;; it is not -1, we jump using the value as jump target. since we can always 133 ;; change 1's to 0's without erasing the sector, it is possible to add new 134 ;; code after this and altering the jumptarget in an upgrade. 135 136jtcd: move.d [jumptarget], $r0 137 cmp.d 0xffffffff, $r0 138 beq no_newjump 139 nop 140 141 jump [$r0] 142 143jumptarget: 144 .dword 0xffffffff ; can be overwritten later to insert new code 145 146no_newjump: 147#ifdef CONFIG_ETRAX_ETHERNET 148 ;; Start MII clock to make sure it is running when tranceiver is reset 149 move.d 0x3, $r0 ; enable = on, phy = mii_clk 150 move.d $r0, [R_NETWORK_GEN_CONFIG] 151#endif 152 153 ;; Setup port PA and PB default initial directions and data 154 ;; (so we can flash LEDs, and so that DTR and others are set) 155 156 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0 157 move.b $r0, [R_PORT_PA_DIR] 158 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0 159 move.b $r0, [R_PORT_PA_DATA] 160 161 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0 162 move.b $r0, [R_PORT_PB_DIR] 163 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0 164 move.b $r0, [R_PORT_PB_DATA] 165 166 ;; We need to setup the bus registers before we start using the DRAM 167#include "../../lib/dram_init.S" 168 169 ;; we now should go through the checksum-table and check the listed 170 ;; partitions for errors. 171 172 move.d PTABLE_START, $r3 173 move.d [$r3], $r0 174 cmp.d NOP_DI, $r0 ; make sure the nop/di is there... 175 bne do_rescue 176 nop 177 178 ;; skip the code transparency block (10 bytes). 179 180 addq 10, $r3 181 182 ;; check for correct magic 183 184 move.w [$r3+], $r0 185 cmp.w PTABLE_MAGIC, $r0 186 bne do_rescue ; didn't recognize - trig rescue 187 nop 188 189 ;; check for correct ptable checksum 190 191 movu.w [$r3+], $r2 ; ptable length 192 move.d $r2, $r8 ; save for later, length of total ptable 193 addq 28, $r8 ; account for the rest 194 move.d [$r3+], $r4 ; ptable checksum 195 move.d $r3, $r1 196 jsr checksum ; r1 source, r2 length, returns in r0 197 198 cmp.d $r0, $r4 199 bne do_rescue ; didn't match - trig rescue 200 nop 201 202 ;; ptable is ok. validate each entry. 203 204 moveq -1, $r7 205 206ploop: move.d [$r3+], $r1 ; partition offset (from ptable start) 207 bne notfirst ; check if it is the partition containing ptable 208 nop ; yes.. 209 move.d $r8, $r1 ; for its checksum check, skip the ptable 210 move.d [$r3+], $r2 ; partition length 211 sub.d $r8, $r2 ; minus the ptable length 212 ba bosse 213 nop 214notfirst: 215 cmp.d -1, $r1 ; the end of the ptable ? 216 beq flash_ok ; if so, the flash is validated 217 move.d [$r3+], $r2 ; partition length 218bosse: move.d [$r3+], $r5 ; checksum 219 move.d [$r3+], $r4 ; type and flags 220 addq 16, $r3 ; skip the reserved bytes 221 btstq 16, $r4 ; check ro flag 222 bpl ploop ; rw partition, skip validation 223 nop 224 btstq 17, $r4 ; check bootable flag 225 bpl 1f 226 nop 227 move.d $r1, $r7 ; remember boot partition offset 2281: 229 230 add.d PTABLE_START, $r1 231 232 jsr checksum ; checksum the partition 233 234 cmp.d $r0, $r5 235 beq ploop ; checksums matched, go to next entry 236 nop 237 238 ;; otherwise fall through to the rescue code. 239 240do_rescue: 241 242 ;; setup the serial port at 115200 baud 243 244 moveq 0, $r0 245 move.d $r0, [SERXOFF] 246 247 move.b 0x99, $r0 248 move.b $r0, [SERBAUD] ; 115.2kbaud for both transmit and receive 249 250 move.b 0x40, $r0 ; rec enable 251 move.b $r0, [SERRECC] 252 253 moveq 0, $r1 ; "timer" to clock out a LED red flash 254 move.d CODE_START, $r3 ; destination counter 255 movu.w CODE_LENGTH, $r4; length 256 257wait_ser: 258 addq 1, $r1 259#ifndef CONFIG_ETRAX_NO_LEDS 260#ifdef CONFIG_ETRAX_PA_LEDS 261 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2 262#endif 263#ifdef CONFIG_ETRAX_PB_LEDS 264 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2 265#endif 266 move.d (1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0 267 btstq 16, $r1 268 bpl 1f 269 nop 270 or.d $r0, $r2 ; set bit 271 ba 2f 272 nop 2731: not $r0 ; clear bit 274 and.d $r0, $r2 2752: 276#ifdef CONFIG_ETRAX_PA_LEDS 277 move.b $r2, [R_PORT_PA_DATA] 278#endif 279#ifdef CONFIG_ETRAX_PB_LEDS 280 move.b $r2, [R_PORT_PB_DATA] 281#endif 282#ifdef CONFIG_ETRAX_90000000_LEDS 283 move.b $r2, [0x90000000] 284#endif 285#endif 286 287 ;; check if we got something on the serial port 288 289 move.b [SERSTAT], $r0 290 btstq 0, $r0 ; data_avail 291 bpl wait_ser 292 nop 293 294 ;; got something - copy the byte and loop 295 296 move.b [SERRDAT], $r0 297 move.b $r0, [$r3+] 298 299 subq 1, $r4 ; decrease length 300 bne wait_ser 301 nop 302 303 ;; jump into downloaded code 304 305 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is initialized 306 jump CODE_START 307 308flash_ok: 309 ;; check r7, which contains either -1 or the partition to boot from 310 311 cmp.d -1, $r7 312 bne 1f 313 nop 314 move.d PTABLE_START, $r7; otherwise use the ptable start 3151: 316 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is initialized 317 jump $r7 ; boot! 318 319 320 ;; Helper subroutines 321 322 ;; Will checksum by simple addition 323 ;; r1 - source 324 ;; r2 - length in bytes 325 ;; result will be in r0 326checksum: 327 moveq 0, $r0 3281: addu.b [$r1+], $r0 329 subq 1, $r2 330 bne 1b 331 nop 332 ret 333 nop 334