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 can't 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