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.
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.
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.
22 * Partition table format:
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]
31 * Table validation (at +10):
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]
37 * Entries, each with the following format, last has offset -1:
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]
50 * 10 bytes [0, padding]
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.
59 * During the wait for serial input, the status LED will flash so the
60 * user knows something went wrong.
62 * Copyright (C) 1999, 2000, 2001, 2002, 2003 Axis Communications AB
65 #include <linux/config.h>
66 #define ASSEMBLER_MACROS_ONLY
67 #include <asm/sv_addr_ag.h>
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.
72 #define PTABLE_START CONFIG_ETRAX_PTABLE_SECTOR
73 #define PTABLE_MAGIC 0xbeef
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.
82 #define CODE_START 0x40000000
83 #define CODE_LENGTH 784
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
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
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
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
114 #define NOP_DI 0xf025050f
115 #define RAM_INIT_MAGIC 0x56902387
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
127 jump in_cache ; enter cached area instead
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.
136 jtcd: move.d [jumptarget], $r0
137 cmp.d 0xffffffff, $r0
144 .dword 0xffffffff ; can be overwritten later to insert new code
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]
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)
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]
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]
166 ;; We need to setup the bus registers before we start using the DRAM
167 #include "../../lib/dram_init.S"
169 ;; we now should go through the checksum-table and check the listed
170 ;; partitions for errors.
172 move.d PTABLE_START, $r3
174 cmp.d NOP_DI, $r0 ; make sure the nop/di is there...
178 ;; skip the code transparency block (10 bytes).
182 ;; check for correct magic
185 cmp.w PTABLE_MAGIC, $r0
186 bne do_rescue ; didn't recognize - trig rescue
189 ;; check for correct ptable checksum
191 movu.w [$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+], $r4 ; ptable checksum
196 jsr checksum ; r1 source, r2 length, returns in r0
199 bne do_rescue ; didn't match - trig rescue
202 ;; ptable is ok. validate each entry.
206 ploop: move.d [$r3+], $r1 ; partition offset (from ptable start)
207 bne notfirst ; check if it is the partition containing ptable
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
215 cmp.d -1, $r1 ; the end of the ptable ?
216 beq flash_ok ; if so, the flash is validated
217 move.d [$r3+], $r2 ; partition length
218 bosse: move.d [$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
224 btstq 17, $r4 ; check bootable flag
227 move.d $r1, $r7 ; remember boot partition offset
230 add.d PTABLE_START, $r1
232 jsr checksum ; checksum the partition
235 beq ploop ; checksums matched, go to next entry
238 ;; otherwise fall through to the rescue code.
242 ;; setup the serial port at 115200 baud
245 move.d $r0, [SERXOFF]
248 move.b $r0, [SERBAUD] ; 115.2kbaud for both transmit and receive
250 move.b 0x40, $r0 ; rec enable
251 move.b $r0, [SERRECC]
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
259 #ifndef CONFIG_ETRAX_NO_LEDS
260 #ifdef CONFIG_ETRAX_PA_LEDS
261 move.b CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2
263 #ifdef CONFIG_ETRAX_PB_LEDS
264 move.b CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2
266 move.d (1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0
270 or.d $r0, $r2 ; set bit
273 1: not $r0 ; clear bit
276 #ifdef CONFIG_ETRAX_PA_LEDS
277 move.b $r2, [R_PORT_PA_DATA]
279 #ifdef CONFIG_ETRAX_PB_LEDS
280 move.b $r2, [R_PORT_PB_DATA]
282 #ifdef CONFIG_ETRAX_90000000_LEDS
283 move.b $r2, [0x90000000]
287 ;; check if we got something on the serial port
289 move.b [SERSTAT], $r0
290 btstq 0, $r0 ; data_avail
294 ;; got something - copy the byte and loop
296 move.b [SERRDAT], $r0
299 subq 1, $r4 ; decrease length
303 ;; jump into downloaded code
305 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is initialized
309 ;; check r7, which contains either -1 or the partition to boot from
314 move.d PTABLE_START, $r7; otherwise use the ptable start
316 move.d RAM_INIT_MAGIC, $r8 ; Tell next product that DRAM is initialized
320 ;; Helper subroutines
322 ;; Will checksum by simple addition
324 ;; r2 - length in bytes
325 ;; result will be in r0
328 1: addu.b [$r1+], $r0