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907208c4 CL |
1 | /* |
2 | * Copyright (C) 1998 Dan Malek <dmalek@jlc.net> | |
3 | * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> | |
4 | * Copyright (C) 2000,2001,2002 Wolfgang Denk <wd@denx.de> | |
5 | * | |
6 | * SPDX-License-Identifier: GPL-2.0+ | |
7 | */ | |
8 | ||
9 | /* U-Boot - Startup Code for PowerPC based Embedded Boards | |
10 | * | |
11 | * | |
12 | * The processor starts at 0x00000100 and the code is executed | |
13 | * from flash. The code is organized to be at an other address | |
14 | * in memory, but as long we don't jump around before relocating, | |
15 | * board_init lies at a quite high address and when the cpu has | |
16 | * jumped there, everything is ok. | |
17 | * This works because the cpu gives the FLASH (CS0) the whole | |
18 | * address space at startup, and board_init lies as a echo of | |
19 | * the flash somewhere up there in the memory map. | |
20 | * | |
21 | * board_init will change CS0 to be positioned at the correct | |
22 | * address and (s)dram will be positioned at address 0 | |
23 | */ | |
24 | #include <asm-offsets.h> | |
25 | #include <config.h> | |
26 | #include <mpc8xx.h> | |
27 | #include <version.h> | |
28 | ||
29 | #include <ppc_asm.tmpl> | |
30 | #include <ppc_defs.h> | |
31 | ||
32 | #include <asm/cache.h> | |
33 | #include <asm/mmu.h> | |
34 | #include <asm/u-boot.h> | |
35 | ||
36 | /* We don't want the MMU yet. | |
37 | */ | |
38 | #undef MSR_KERNEL | |
39 | #define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */ | |
40 | ||
41 | /* | |
42 | * Set up GOT: Global Offset Table | |
43 | * | |
44 | * Use r12 to access the GOT | |
45 | */ | |
46 | START_GOT | |
47 | GOT_ENTRY(_GOT2_TABLE_) | |
48 | GOT_ENTRY(_FIXUP_TABLE_) | |
49 | ||
50 | GOT_ENTRY(_start) | |
51 | GOT_ENTRY(_start_of_vectors) | |
52 | GOT_ENTRY(_end_of_vectors) | |
53 | GOT_ENTRY(transfer_to_handler) | |
54 | ||
55 | GOT_ENTRY(__init_end) | |
56 | GOT_ENTRY(__bss_end) | |
57 | GOT_ENTRY(__bss_start) | |
58 | END_GOT | |
59 | ||
60 | /* | |
61 | * r3 - 1st arg to board_init(): IMMP pointer | |
62 | * r4 - 2nd arg to board_init(): boot flag | |
63 | */ | |
64 | .text | |
65 | .long 0x27051956 /* U-Boot Magic Number */ | |
66 | .globl version_string | |
67 | version_string: | |
68 | .ascii U_BOOT_VERSION_STRING, "\0" | |
69 | ||
70 | . = EXC_OFF_SYS_RESET | |
71 | .globl _start | |
72 | _start: | |
73 | lis r3, CONFIG_SYS_IMMR@h /* position IMMR */ | |
74 | mtspr 638, r3 | |
75 | ||
76 | /* Initialize machine status; enable machine check interrupt */ | |
77 | /*----------------------------------------------------------------------*/ | |
78 | li r3, MSR_KERNEL /* Set ME, RI flags */ | |
79 | mtmsr r3 | |
80 | mtspr SRR1, r3 /* Make SRR1 match MSR */ | |
81 | ||
82 | mfspr r3, ICR /* clear Interrupt Cause Register */ | |
83 | ||
84 | /* Initialize debug port registers */ | |
85 | /*----------------------------------------------------------------------*/ | |
86 | xor r0, r0, r0 /* Clear R0 */ | |
87 | mtspr LCTRL1, r0 /* Initialize debug port regs */ | |
88 | mtspr LCTRL2, r0 | |
89 | mtspr COUNTA, r0 | |
90 | mtspr COUNTB, r0 | |
91 | ||
92 | /* Reset the caches */ | |
93 | /*----------------------------------------------------------------------*/ | |
94 | ||
95 | mfspr r3, IC_CST /* Clear error bits */ | |
96 | mfspr r3, DC_CST | |
97 | ||
98 | lis r3, IDC_UNALL@h /* Unlock all */ | |
99 | mtspr IC_CST, r3 | |
100 | mtspr DC_CST, r3 | |
101 | ||
102 | lis r3, IDC_INVALL@h /* Invalidate all */ | |
103 | mtspr IC_CST, r3 | |
104 | mtspr DC_CST, r3 | |
105 | ||
106 | lis r3, IDC_DISABLE@h /* Disable data cache */ | |
107 | mtspr DC_CST, r3 | |
108 | ||
109 | lis r3, IDC_ENABLE@h /* Enable instruction cache */ | |
110 | mtspr IC_CST, r3 | |
111 | ||
112 | /* invalidate all tlb's */ | |
113 | /*----------------------------------------------------------------------*/ | |
114 | ||
115 | tlbia | |
116 | isync | |
117 | ||
118 | /* | |
119 | * Calculate absolute address in FLASH and jump there | |
120 | *----------------------------------------------------------------------*/ | |
121 | ||
122 | lis r3, CONFIG_SYS_MONITOR_BASE@h | |
123 | ori r3, r3, CONFIG_SYS_MONITOR_BASE@l | |
124 | addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET | |
125 | mtlr r3 | |
126 | blr | |
127 | ||
128 | in_flash: | |
129 | ||
130 | /* initialize some SPRs that are hard to access from C */ | |
131 | /*----------------------------------------------------------------------*/ | |
132 | ||
133 | lis r3, CONFIG_SYS_IMMR@h /* pass IMMR as arg1 to C routine */ | |
134 | ori r1, r3, CONFIG_SYS_INIT_SP_OFFSET /* set up the stack in internal DPRAM */ | |
135 | /* Note: R0 is still 0 here */ | |
136 | stwu r0, -4(r1) /* clear final stack frame so that */ | |
137 | stwu r0, -4(r1) /* stack backtraces terminate cleanly */ | |
138 | ||
139 | /* | |
140 | * Disable serialized ifetch and show cycles | |
141 | * (i.e. set processor to normal mode). | |
142 | * This is also a silicon bug workaround, see errata | |
143 | */ | |
144 | ||
145 | li r2, 0x0007 | |
146 | mtspr ICTRL, r2 | |
147 | ||
148 | /* Set up debug mode entry */ | |
149 | ||
150 | lis r2, CONFIG_SYS_DER@h | |
151 | ori r2, r2, CONFIG_SYS_DER@l | |
152 | mtspr DER, r2 | |
153 | ||
154 | /* let the C-code set up the rest */ | |
155 | /* */ | |
156 | /* Be careful to keep code relocatable ! */ | |
157 | /*----------------------------------------------------------------------*/ | |
158 | ||
159 | GET_GOT /* initialize GOT access */ | |
160 | ||
161 | /* r3: IMMR */ | |
162 | bl cpu_init_f /* run low-level CPU init code (from Flash) */ | |
163 | ||
164 | bl board_init_f /* run 1st part of board init code (from Flash) */ | |
165 | ||
166 | /* NOTREACHED - board_init_f() does not return */ | |
167 | ||
168 | ||
169 | .globl _start_of_vectors | |
170 | _start_of_vectors: | |
171 | ||
172 | /* Machine check */ | |
173 | STD_EXCEPTION(0x200, MachineCheck, MachineCheckException) | |
174 | ||
175 | /* Data Storage exception. "Never" generated on the 860. */ | |
176 | STD_EXCEPTION(0x300, DataStorage, UnknownException) | |
177 | ||
178 | /* Instruction Storage exception. "Never" generated on the 860. */ | |
179 | STD_EXCEPTION(0x400, InstStorage, UnknownException) | |
180 | ||
181 | /* External Interrupt exception. */ | |
182 | STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt) | |
183 | ||
184 | /* Alignment exception. */ | |
185 | . = 0x600 | |
186 | Alignment: | |
187 | EXCEPTION_PROLOG(SRR0, SRR1) | |
188 | mfspr r4,DAR | |
189 | stw r4,_DAR(r21) | |
190 | mfspr r5,DSISR | |
191 | stw r5,_DSISR(r21) | |
192 | addi r3,r1,STACK_FRAME_OVERHEAD | |
193 | EXC_XFER_TEMPLATE(Alignment, AlignmentException, MSR_KERNEL, COPY_EE) | |
194 | ||
195 | /* Program check exception */ | |
196 | . = 0x700 | |
197 | ProgramCheck: | |
198 | EXCEPTION_PROLOG(SRR0, SRR1) | |
199 | addi r3,r1,STACK_FRAME_OVERHEAD | |
200 | EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException, | |
201 | MSR_KERNEL, COPY_EE) | |
202 | ||
203 | /* No FPU on MPC8xx. This exception is not supposed to happen. | |
204 | */ | |
205 | STD_EXCEPTION(0x800, FPUnavailable, UnknownException) | |
206 | ||
207 | /* I guess we could implement decrementer, and may have | |
208 | * to someday for timekeeping. | |
209 | */ | |
210 | STD_EXCEPTION(0x900, Decrementer, timer_interrupt) | |
211 | STD_EXCEPTION(0xa00, Trap_0a, UnknownException) | |
212 | STD_EXCEPTION(0xb00, Trap_0b, UnknownException) | |
213 | STD_EXCEPTION(0xc00, SystemCall, UnknownException) | |
214 | STD_EXCEPTION(0xd00, SingleStep, UnknownException) | |
215 | ||
216 | STD_EXCEPTION(0xe00, Trap_0e, UnknownException) | |
217 | STD_EXCEPTION(0xf00, Trap_0f, UnknownException) | |
218 | ||
219 | /* On the MPC8xx, this is a software emulation interrupt. It occurs | |
220 | * for all unimplemented and illegal instructions. | |
221 | */ | |
222 | STD_EXCEPTION(0x1000, SoftEmu, SoftEmuException) | |
223 | ||
224 | STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException) | |
225 | STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException) | |
226 | STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException) | |
227 | STD_EXCEPTION(0x1400, DataTLBError, UnknownException) | |
228 | ||
229 | STD_EXCEPTION(0x1500, Reserved5, UnknownException) | |
230 | STD_EXCEPTION(0x1600, Reserved6, UnknownException) | |
231 | STD_EXCEPTION(0x1700, Reserved7, UnknownException) | |
232 | STD_EXCEPTION(0x1800, Reserved8, UnknownException) | |
233 | STD_EXCEPTION(0x1900, Reserved9, UnknownException) | |
234 | STD_EXCEPTION(0x1a00, ReservedA, UnknownException) | |
235 | STD_EXCEPTION(0x1b00, ReservedB, UnknownException) | |
236 | ||
237 | STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException) | |
238 | STD_EXCEPTION(0x1d00, InstructionBreakpoint, DebugException) | |
239 | STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException) | |
240 | STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException) | |
241 | ||
242 | ||
243 | .globl _end_of_vectors | |
244 | _end_of_vectors: | |
245 | ||
246 | ||
247 | . = 0x2000 | |
248 | ||
249 | /* | |
250 | * This code finishes saving the registers to the exception frame | |
251 | * and jumps to the appropriate handler for the exception. | |
252 | * Register r21 is pointer into trap frame, r1 has new stack pointer. | |
253 | */ | |
254 | .globl transfer_to_handler | |
255 | transfer_to_handler: | |
256 | stw r22,_NIP(r21) | |
257 | lis r22,MSR_POW@h | |
258 | andc r23,r23,r22 | |
259 | stw r23,_MSR(r21) | |
260 | SAVE_GPR(7, r21) | |
261 | SAVE_4GPRS(8, r21) | |
262 | SAVE_8GPRS(12, r21) | |
263 | SAVE_8GPRS(24, r21) | |
264 | mflr r23 | |
265 | andi. r24,r23,0x3f00 /* get vector offset */ | |
266 | stw r24,TRAP(r21) | |
267 | li r22,0 | |
268 | stw r22,RESULT(r21) | |
269 | mtspr SPRG2,r22 /* r1 is now kernel sp */ | |
270 | lwz r24,0(r23) /* virtual address of handler */ | |
271 | lwz r23,4(r23) /* where to go when done */ | |
272 | mtspr SRR0,r24 | |
273 | mtspr SRR1,r20 | |
274 | mtlr r23 | |
275 | SYNC | |
276 | rfi /* jump to handler, enable MMU */ | |
277 | ||
278 | int_return: | |
279 | mfmsr r28 /* Disable interrupts */ | |
280 | li r4,0 | |
281 | ori r4,r4,MSR_EE | |
282 | andc r28,r28,r4 | |
283 | SYNC /* Some chip revs need this... */ | |
284 | mtmsr r28 | |
285 | SYNC | |
286 | lwz r2,_CTR(r1) | |
287 | lwz r0,_LINK(r1) | |
288 | mtctr r2 | |
289 | mtlr r0 | |
290 | lwz r2,_XER(r1) | |
291 | lwz r0,_CCR(r1) | |
292 | mtspr XER,r2 | |
293 | mtcrf 0xFF,r0 | |
294 | REST_10GPRS(3, r1) | |
295 | REST_10GPRS(13, r1) | |
296 | REST_8GPRS(23, r1) | |
297 | REST_GPR(31, r1) | |
298 | lwz r2,_NIP(r1) /* Restore environment */ | |
299 | lwz r0,_MSR(r1) | |
300 | mtspr SRR0,r2 | |
301 | mtspr SRR1,r0 | |
302 | lwz r0,GPR0(r1) | |
303 | lwz r2,GPR2(r1) | |
304 | lwz r1,GPR1(r1) | |
305 | SYNC | |
306 | rfi | |
307 | ||
907208c4 CL |
308 | .globl get_pvr |
309 | get_pvr: | |
310 | mfspr r3, PVR | |
311 | blr | |
312 | ||
907208c4 CL |
313 | /*------------------------------------------------------------------------------*/ |
314 | ||
315 | /* | |
316 | * void relocate_code (addr_sp, gd, addr_moni) | |
317 | * | |
318 | * This "function" does not return, instead it continues in RAM | |
319 | * after relocating the monitor code. | |
320 | * | |
321 | * r3 = dest | |
322 | * r4 = src | |
323 | * r5 = length in bytes | |
324 | * r6 = cachelinesize | |
325 | */ | |
326 | .globl relocate_code | |
327 | relocate_code: | |
328 | mr r1, r3 /* Set new stack pointer */ | |
329 | mr r9, r4 /* Save copy of Global Data pointer */ | |
330 | mr r10, r5 /* Save copy of Destination Address */ | |
331 | ||
332 | GET_GOT | |
333 | mr r3, r5 /* Destination Address */ | |
334 | lis r4, CONFIG_SYS_MONITOR_BASE@h /* Source Address */ | |
335 | ori r4, r4, CONFIG_SYS_MONITOR_BASE@l | |
336 | lwz r5, GOT(__init_end) | |
337 | sub r5, r5, r4 | |
338 | li r6, CONFIG_SYS_CACHELINE_SIZE /* Cache Line Size */ | |
339 | ||
340 | /* | |
341 | * Fix GOT pointer: | |
342 | * | |
343 | * New GOT-PTR = (old GOT-PTR - CONFIG_SYS_MONITOR_BASE) + Destination Address | |
344 | * | |
345 | * Offset: | |
346 | */ | |
347 | sub r15, r10, r4 | |
348 | ||
349 | /* First our own GOT */ | |
350 | add r12, r12, r15 | |
351 | /* then the one used by the C code */ | |
352 | add r30, r30, r15 | |
353 | ||
354 | /* | |
355 | * Now relocate code | |
356 | */ | |
357 | ||
358 | cmplw cr1,r3,r4 | |
359 | addi r0,r5,3 | |
360 | srwi. r0,r0,2 | |
361 | beq cr1,4f /* In place copy is not necessary */ | |
362 | beq 7f /* Protect against 0 count */ | |
363 | mtctr r0 | |
364 | bge cr1,2f | |
365 | ||
366 | la r8,-4(r4) | |
367 | la r7,-4(r3) | |
368 | 1: lwzu r0,4(r8) | |
369 | stwu r0,4(r7) | |
370 | bdnz 1b | |
371 | b 4f | |
372 | ||
373 | 2: slwi r0,r0,2 | |
374 | add r8,r4,r0 | |
375 | add r7,r3,r0 | |
376 | 3: lwzu r0,-4(r8) | |
377 | stwu r0,-4(r7) | |
378 | bdnz 3b | |
379 | ||
380 | /* | |
381 | * Now flush the cache: note that we must start from a cache aligned | |
382 | * address. Otherwise we might miss one cache line. | |
383 | */ | |
384 | 4: cmpwi r6,0 | |
385 | add r5,r3,r5 | |
386 | beq 7f /* Always flush prefetch queue in any case */ | |
387 | subi r0,r6,1 | |
388 | andc r3,r3,r0 | |
389 | mr r4,r3 | |
390 | 5: dcbst 0,r4 | |
391 | add r4,r4,r6 | |
392 | cmplw r4,r5 | |
393 | blt 5b | |
394 | sync /* Wait for all dcbst to complete on bus */ | |
395 | mr r4,r3 | |
396 | 6: icbi 0,r4 | |
397 | add r4,r4,r6 | |
398 | cmplw r4,r5 | |
399 | blt 6b | |
400 | 7: sync /* Wait for all icbi to complete on bus */ | |
401 | isync | |
402 | ||
403 | /* | |
404 | * We are done. Do not return, instead branch to second part of board | |
405 | * initialization, now running from RAM. | |
406 | */ | |
407 | ||
408 | addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET | |
409 | mtlr r0 | |
410 | blr | |
411 | ||
412 | in_ram: | |
413 | ||
414 | /* | |
415 | * Relocation Function, r12 point to got2+0x8000 | |
416 | * | |
417 | * Adjust got2 pointers, no need to check for 0, this code | |
418 | * already puts a few entries in the table. | |
419 | */ | |
420 | li r0,__got2_entries@sectoff@l | |
421 | la r3,GOT(_GOT2_TABLE_) | |
422 | lwz r11,GOT(_GOT2_TABLE_) | |
423 | mtctr r0 | |
424 | sub r11,r3,r11 | |
425 | addi r3,r3,-4 | |
426 | 1: lwzu r0,4(r3) | |
427 | cmpwi r0,0 | |
428 | beq- 2f | |
429 | add r0,r0,r11 | |
430 | stw r0,0(r3) | |
431 | 2: bdnz 1b | |
432 | ||
433 | /* | |
434 | * Now adjust the fixups and the pointers to the fixups | |
435 | * in case we need to move ourselves again. | |
436 | */ | |
437 | li r0,__fixup_entries@sectoff@l | |
438 | lwz r3,GOT(_FIXUP_TABLE_) | |
439 | cmpwi r0,0 | |
440 | mtctr r0 | |
441 | addi r3,r3,-4 | |
442 | beq 4f | |
443 | 3: lwzu r4,4(r3) | |
444 | lwzux r0,r4,r11 | |
445 | cmpwi r0,0 | |
446 | add r0,r0,r11 | |
447 | stw r4,0(r3) | |
448 | beq- 5f | |
449 | stw r0,0(r4) | |
450 | 5: bdnz 3b | |
451 | 4: | |
452 | clear_bss: | |
453 | /* | |
454 | * Now clear BSS segment | |
455 | */ | |
456 | lwz r3,GOT(__bss_start) | |
457 | lwz r4,GOT(__bss_end) | |
458 | ||
459 | cmplw 0, r3, r4 | |
460 | beq 6f | |
461 | ||
462 | li r0, 0 | |
463 | 5: | |
464 | stw r0, 0(r3) | |
465 | addi r3, r3, 4 | |
466 | cmplw 0, r3, r4 | |
467 | bne 5b | |
468 | 6: | |
469 | ||
470 | mr r3, r9 /* Global Data pointer */ | |
471 | mr r4, r10 /* Destination Address */ | |
472 | bl board_init_r | |
473 | ||
474 | /* | |
475 | * Copy exception vector code to low memory | |
476 | * | |
477 | * r3: dest_addr | |
478 | * r7: source address, r8: end address, r9: target address | |
479 | */ | |
480 | .globl trap_init | |
481 | trap_init: | |
482 | mflr r4 /* save link register */ | |
483 | GET_GOT | |
484 | lwz r7, GOT(_start) | |
485 | lwz r8, GOT(_end_of_vectors) | |
486 | ||
487 | li r9, 0x100 /* reset vector always at 0x100 */ | |
488 | ||
489 | cmplw 0, r7, r8 | |
490 | bgelr /* return if r7>=r8 - just in case */ | |
491 | 1: | |
492 | lwz r0, 0(r7) | |
493 | stw r0, 0(r9) | |
494 | addi r7, r7, 4 | |
495 | addi r9, r9, 4 | |
496 | cmplw 0, r7, r8 | |
497 | bne 1b | |
498 | ||
499 | /* | |
500 | * relocate `hdlr' and `int_return' entries | |
501 | */ | |
502 | li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET | |
503 | li r8, Alignment - _start + EXC_OFF_SYS_RESET | |
504 | 2: | |
505 | bl trap_reloc | |
506 | addi r7, r7, 0x100 /* next exception vector */ | |
507 | cmplw 0, r7, r8 | |
508 | blt 2b | |
509 | ||
510 | li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET | |
511 | bl trap_reloc | |
512 | ||
513 | li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET | |
514 | bl trap_reloc | |
515 | ||
516 | li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET | |
517 | li r8, SystemCall - _start + EXC_OFF_SYS_RESET | |
518 | 3: | |
519 | bl trap_reloc | |
520 | addi r7, r7, 0x100 /* next exception vector */ | |
521 | cmplw 0, r7, r8 | |
522 | blt 3b | |
523 | ||
524 | li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET | |
525 | li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET | |
526 | 4: | |
527 | bl trap_reloc | |
528 | addi r7, r7, 0x100 /* next exception vector */ | |
529 | cmplw 0, r7, r8 | |
530 | blt 4b | |
531 | ||
532 | mtlr r4 /* restore link register */ | |
533 | blr |