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  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. * See file CREDITS for list of people who contributed to this
  7. * project.
  8. *
  9. * This program is free software; you can redistribute it and/or
  10. * modify it under the terms of the GNU General Public License as
  11. * published by the Free Software Foundation; either version 2 of
  12. * the License, or (at your option) any later version.
  13. *
  14. * This program is distributed in the hope that it will be useful,
  15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17. * GNU General Public License for more details.
  18. *
  19. * You should have received a copy of the GNU General Public License
  20. * along with this program; if not, write to the Free Software
  21. * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22. * MA 02111-1307 USA
  23. */
  24. /* U-Boot - Startup Code for PowerPC based Embedded Boards
  25. *
  26. *
  27. * The processor starts at 0x00000100 and the code is executed
  28. * from flash. The code is organized to be at an other address
  29. * in memory, but as long we don't jump around before relocating.
  30. * board_init lies at a quite high address and when the cpu has
  31. * jumped there, everything is ok.
  32. * This works because the cpu gives the FLASH (CS0) the whole
  33. * address space at startup, and board_init lies as a echo of
  34. * the flash somewhere up there in the memorymap.
  35. *
  36. * board_init will change CS0 to be positioned at the correct
  37. * address and (s)dram will be positioned at address 0
  38. */
  39. #include <config.h>
  40. #include <mpc8xx.h>
  41. #include <version.h>
  42. #define CONFIG_8xx 1 /* needed for Linux kernel header files */
  43. #define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
  44. #include <ppc_asm.tmpl>
  45. #include <ppc_defs.h>
  46. #include <asm/cache.h>
  47. #include <asm/mmu.h>
  48. #ifndef CONFIG_IDENT_STRING
  49. #define CONFIG_IDENT_STRING ""
  50. #endif
  51. /* We don't want the MMU yet.
  52. */
  53. #undef MSR_KERNEL
  54. #define MSR_KERNEL ( MSR_ME | MSR_RI ) /* Machine Check and Recoverable Interr. */
  55. /*
  56. * Set up GOT: Global Offset Table
  57. *
  58. * Use r14 to access the GOT
  59. */
  60. START_GOT
  61. GOT_ENTRY(_GOT2_TABLE_)
  62. GOT_ENTRY(_FIXUP_TABLE_)
  63. GOT_ENTRY(_start)
  64. GOT_ENTRY(_start_of_vectors)
  65. GOT_ENTRY(_end_of_vectors)
  66. GOT_ENTRY(transfer_to_handler)
  67. GOT_ENTRY(__init_end)
  68. GOT_ENTRY(_end)
  69. GOT_ENTRY(__bss_start)
  70. #if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
  71. GOT_ENTRY(environment)
  72. #endif
  73. END_GOT
  74. /*
  75. * r3 - 1st arg to board_init(): IMMP pointer
  76. * r4 - 2nd arg to board_init(): boot flag
  77. */
  78. .text
  79. .long 0x27051956 /* U-Boot Magic Number */
  80. .globl version_string
  81. version_string:
  82. .ascii U_BOOT_VERSION
  83. .ascii " (", __DATE__, " - ", __TIME__, ")"
  84. .ascii CONFIG_IDENT_STRING, "\0"
  85. . = EXC_OFF_SYS_RESET
  86. .globl _start
  87. _start:
  88. lis r3, CFG_IMMR@h /* position IMMR */
  89. mtspr 638, r3
  90. li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */
  91. b boot_cold
  92. . = EXC_OFF_SYS_RESET + 0x10
  93. .globl _start_warm
  94. _start_warm:
  95. li r21, BOOTFLAG_WARM /* Software reboot */
  96. b boot_warm
  97. boot_cold:
  98. boot_warm:
  99. /* Initialize machine status; enable machine check interrupt */
  100. /*----------------------------------------------------------------------*/
  101. li r3, MSR_KERNEL /* Set ME, RI flags */
  102. mtmsr r3
  103. mtspr SRR1, r3 /* Make SRR1 match MSR */
  104. mfspr r3, ICR /* clear Interrupt Cause Register */
  105. /* Initialize debug port registers */
  106. /*----------------------------------------------------------------------*/
  107. xor r0, r0, r0 /* Clear R0 */
  108. mtspr LCTRL1, r0 /* Initialize debug port regs */
  109. mtspr LCTRL2, r0
  110. mtspr COUNTA, r0
  111. mtspr COUNTB, r0
  112. /* Reset the caches */
  113. /*----------------------------------------------------------------------*/
  114. mfspr r3, IC_CST /* Clear error bits */
  115. mfspr r3, DC_CST
  116. lis r3, IDC_UNALL@h /* Unlock all */
  117. mtspr IC_CST, r3
  118. mtspr DC_CST, r3
  119. lis r3, IDC_INVALL@h /* Invalidate all */
  120. mtspr IC_CST, r3
  121. mtspr DC_CST, r3
  122. lis r3, IDC_DISABLE@h /* Disable data cache */
  123. mtspr DC_CST, r3
  124. #if !(defined(CONFIG_IP860) || defined(CONFIG_PCU_E) || defined (CONFIG_FLAGADM))
  125. /* On IP860 and PCU E,
  126. * we cannot enable IC yet
  127. */
  128. lis r3, IDC_ENABLE@h /* Enable instruction cache */
  129. #endif
  130. mtspr IC_CST, r3
  131. /* invalidate all tlb's */
  132. /*----------------------------------------------------------------------*/
  133. tlbia
  134. isync
  135. /*
  136. * Calculate absolute address in FLASH and jump there
  137. *----------------------------------------------------------------------*/
  138. lis r3, CFG_MONITOR_BASE@h
  139. ori r3, r3, CFG_MONITOR_BASE@l
  140. addi r3, r3, in_flash - _start + EXC_OFF_SYS_RESET
  141. mtlr r3
  142. blr
  143. in_flash:
  144. /* initialize some SPRs that are hard to access from C */
  145. /*----------------------------------------------------------------------*/
  146. lis r3, CFG_IMMR@h /* pass IMMR as arg1 to C routine */
  147. ori r1, r3, CFG_INIT_SP_OFFSET /* set up the stack in internal DPRAM */
  148. /* Note: R0 is still 0 here */
  149. stwu r0, -4(r1) /* clear final stack frame so that */
  150. stwu r0, -4(r1) /* stack backtraces terminate cleanly */
  151. /*
  152. * Disable serialized ifetch and show cycles
  153. * (i.e. set processor to normal mode).
  154. * This is also a silicon bug workaround, see errata
  155. */
  156. li r2, 0x0007
  157. mtspr ICTRL, r2
  158. /* Set up debug mode entry */
  159. lis r2, CFG_DER@h
  160. ori r2, r2, CFG_DER@l
  161. mtspr DER, r2
  162. /* let the C-code set up the rest */
  163. /* */
  164. /* Be careful to keep code relocatable ! */
  165. /*----------------------------------------------------------------------*/
  166. GET_GOT /* initialize GOT access */
  167. /* r3: IMMR */
  168. bl cpu_init_f /* run low-level CPU init code (from Flash) */
  169. mr r3, r21
  170. /* r3: BOOTFLAG */
  171. bl board_init_f /* run 1st part of board init code (from Flash) */
  172. .globl _start_of_vectors
  173. _start_of_vectors:
  174. /* Machine check */
  175. STD_EXCEPTION(0x200, MachineCheck, MachineCheckException)
  176. /* Data Storage exception. "Never" generated on the 860. */
  177. STD_EXCEPTION(0x300, DataStorage, UnknownException)
  178. /* Instruction Storage exception. "Never" generated on the 860. */
  179. STD_EXCEPTION(0x400, InstStorage, UnknownException)
  180. /* External Interrupt exception. */
  181. STD_EXCEPTION(0x500, ExtInterrupt, external_interrupt)
  182. /* Alignment exception. */
  183. . = 0x600
  184. Alignment:
  185. EXCEPTION_PROLOG
  186. mfspr r4,DAR
  187. stw r4,_DAR(r21)
  188. mfspr r5,DSISR
  189. stw r5,_DSISR(r21)
  190. addi r3,r1,STACK_FRAME_OVERHEAD
  191. li r20,MSR_KERNEL
  192. rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
  193. lwz r6,GOT(transfer_to_handler)
  194. mtlr r6
  195. blrl
  196. .L_Alignment:
  197. .long AlignmentException - _start + EXC_OFF_SYS_RESET
  198. .long int_return - _start + EXC_OFF_SYS_RESET
  199. /* Program check exception */
  200. . = 0x700
  201. ProgramCheck:
  202. EXCEPTION_PROLOG
  203. addi r3,r1,STACK_FRAME_OVERHEAD
  204. li r20,MSR_KERNEL
  205. rlwimi r20,r23,0,16,16 /* copy EE bit from saved MSR */
  206. lwz r6,GOT(transfer_to_handler)
  207. mtlr r6
  208. blrl
  209. .L_ProgramCheck:
  210. .long ProgramCheckException - _start + EXC_OFF_SYS_RESET
  211. .long int_return - _start + EXC_OFF_SYS_RESET
  212. /* No FPU on MPC8xx. This exception is not supposed to happen.
  213. */
  214. STD_EXCEPTION(0x800, FPUnavailable, UnknownException)
  215. /* I guess we could implement decrementer, and may have
  216. * to someday for timekeeping.
  217. */
  218. STD_EXCEPTION(0x900, Decrementer, timer_interrupt)
  219. STD_EXCEPTION(0xa00, Trap_0a, UnknownException)
  220. STD_EXCEPTION(0xb00, Trap_0b, UnknownException)
  221. . = 0xc00
  222. /*
  223. * r0 - SYSCALL number
  224. * r3-... arguments
  225. */
  226. SystemCall:
  227. addis r11,r0,0 /* get functions table addr */
  228. ori r11,r11,0 /* Note: this code is patched in trap_init */
  229. addis r12,r0,0 /* get number of functions */
  230. ori r12,r12,0
  231. cmplw 0, r0, r12
  232. bge 1f
  233. rlwinm r0,r0,2,0,31 /* fn_addr = fn_tbl[r0] */
  234. add r11,r11,r0
  235. lwz r11,0(r11)
  236. li r20,0xd00-4 /* Get stack pointer */
  237. lwz r12,0(r20)
  238. subi r12,r12,12 /* Adjust stack pointer */
  239. li r0,0xc00+_end_back-SystemCall
  240. cmplw 0, r0, r12 /* Check stack overflow */
  241. bgt 1f
  242. stw r12,0(r20)
  243. mflr r0
  244. stw r0,0(r12)
  245. mfspr r0,SRR0
  246. stw r0,4(r12)
  247. mfspr r0,SRR1
  248. stw r0,8(r12)
  249. li r12,0xc00+_back-SystemCall
  250. mtlr r12
  251. mtspr SRR0,r11
  252. 1: SYNC
  253. rfi
  254. _back:
  255. mfmsr r11 /* Disable interrupts */
  256. li r12,0
  257. ori r12,r12,MSR_EE
  258. andc r11,r11,r12
  259. SYNC /* Some chip revs need this... */
  260. mtmsr r11
  261. SYNC
  262. li r12,0xd00-4 /* restore regs */
  263. lwz r12,0(r12)
  264. lwz r11,0(r12)
  265. mtlr r11
  266. lwz r11,4(r12)
  267. mtspr SRR0,r11
  268. lwz r11,8(r12)
  269. mtspr SRR1,r11
  270. addi r12,r12,12 /* Adjust stack pointer */
  271. li r20,0xd00-4
  272. stw r12,0(r20)
  273. SYNC
  274. rfi
  275. _end_back:
  276. STD_EXCEPTION(0xd00, SingleStep, UnknownException)
  277. STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
  278. STD_EXCEPTION(0xf00, Trap_0f, UnknownException)
  279. /* On the MPC8xx, this is a software emulation interrupt. It occurs
  280. * for all unimplemented and illegal instructions.
  281. */
  282. STD_EXCEPTION(0x1000, SoftEmu, SoftEmuException)
  283. STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException)
  284. STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException)
  285. STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException)
  286. STD_EXCEPTION(0x1400, DataTLBError, UnknownException)
  287. STD_EXCEPTION(0x1500, Reserved5, UnknownException)
  288. STD_EXCEPTION(0x1600, Reserved6, UnknownException)
  289. STD_EXCEPTION(0x1700, Reserved7, UnknownException)
  290. STD_EXCEPTION(0x1800, Reserved8, UnknownException)
  291. STD_EXCEPTION(0x1900, Reserved9, UnknownException)
  292. STD_EXCEPTION(0x1a00, ReservedA, UnknownException)
  293. STD_EXCEPTION(0x1b00, ReservedB, UnknownException)
  294. STD_EXCEPTION(0x1c00, DataBreakpoint, UnknownException)
  295. STD_EXCEPTION(0x1d00, InstructionBreakpoint, DebugException)
  296. STD_EXCEPTION(0x1e00, PeripheralBreakpoint, UnknownException)
  297. STD_EXCEPTION(0x1f00, DevPortBreakpoint, UnknownException)
  298. .globl _end_of_vectors
  299. _end_of_vectors:
  300. . = 0x2000
  301. /*
  302. * This code finishes saving the registers to the exception frame
  303. * and jumps to the appropriate handler for the exception.
  304. * Register r21 is pointer into trap frame, r1 has new stack pointer.
  305. */
  306. .globl transfer_to_handler
  307. transfer_to_handler:
  308. stw r22,_NIP(r21)
  309. lis r22,MSR_POW@h
  310. andc r23,r23,r22
  311. stw r23,_MSR(r21)
  312. SAVE_GPR(7, r21)
  313. SAVE_4GPRS(8, r21)
  314. SAVE_8GPRS(12, r21)
  315. SAVE_8GPRS(24, r21)
  316. mflr r23
  317. andi. r24,r23,0x3f00 /* get vector offset */
  318. stw r24,TRAP(r21)
  319. li r22,0
  320. stw r22,RESULT(r21)
  321. mtspr SPRG2,r22 /* r1 is now kernel sp */
  322. lwz r24,0(r23) /* virtual address of handler */
  323. lwz r23,4(r23) /* where to go when done */
  324. mtspr SRR0,r24
  325. mtspr SRR1,r20
  326. mtlr r23
  327. SYNC
  328. rfi /* jump to handler, enable MMU */
  329. int_return:
  330. mfmsr r28 /* Disable interrupts */
  331. li r4,0
  332. ori r4,r4,MSR_EE
  333. andc r28,r28,r4
  334. SYNC /* Some chip revs need this... */
  335. mtmsr r28
  336. SYNC
  337. lwz r2,_CTR(r1)
  338. lwz r0,_LINK(r1)
  339. mtctr r2
  340. mtlr r0
  341. lwz r2,_XER(r1)
  342. lwz r0,_CCR(r1)
  343. mtspr XER,r2
  344. mtcrf 0xFF,r0
  345. REST_10GPRS(3, r1)
  346. REST_10GPRS(13, r1)
  347. REST_8GPRS(23, r1)
  348. REST_GPR(31, r1)
  349. lwz r2,_NIP(r1) /* Restore environment */
  350. lwz r0,_MSR(r1)
  351. mtspr SRR0,r2
  352. mtspr SRR1,r0
  353. lwz r0,GPR0(r1)
  354. lwz r2,GPR2(r1)
  355. lwz r1,GPR1(r1)
  356. SYNC
  357. rfi
  358. /* Cache functions.
  359. */
  360. .globl icache_enable
  361. icache_enable:
  362. SYNC
  363. lis r3, IDC_INVALL@h
  364. mtspr IC_CST, r3
  365. lis r3, IDC_ENABLE@h
  366. mtspr IC_CST, r3
  367. blr
  368. .globl icache_disable
  369. icache_disable:
  370. SYNC
  371. lis r3, IDC_DISABLE@h
  372. mtspr IC_CST, r3
  373. blr
  374. .globl icache_status
  375. icache_status:
  376. mfspr r3, IC_CST
  377. srwi r3, r3, 31 /* >>31 => select bit 0 */
  378. blr
  379. .globl dcache_enable
  380. dcache_enable:
  381. #if 0
  382. SYNC
  383. #endif
  384. #if 1
  385. lis r3, 0x0400 /* Set cache mode with MMU off */
  386. mtspr MD_CTR, r3
  387. #endif
  388. lis r3, IDC_INVALL@h
  389. mtspr DC_CST, r3
  390. #if 0
  391. lis r3, DC_SFWT@h
  392. mtspr DC_CST, r3
  393. #endif
  394. lis r3, IDC_ENABLE@h
  395. mtspr DC_CST, r3
  396. blr
  397. .globl dcache_disable
  398. dcache_disable:
  399. SYNC
  400. lis r3, IDC_DISABLE@h
  401. mtspr DC_CST, r3
  402. lis r3, IDC_INVALL@h
  403. mtspr DC_CST, r3
  404. blr
  405. .globl dcache_status
  406. dcache_status:
  407. mfspr r3, DC_CST
  408. srwi r3, r3, 31 /* >>31 => select bit 0 */
  409. blr
  410. .globl dc_read
  411. dc_read:
  412. mtspr DC_ADR, r3
  413. mfspr r3, DC_DAT
  414. blr
  415. /*
  416. * unsigned int get_immr (unsigned int mask)
  417. *
  418. * return (mask ? (IMMR & mask) : IMMR);
  419. */
  420. .globl get_immr
  421. get_immr:
  422. mr r4,r3 /* save mask */
  423. mfspr r3, IMMR /* IMMR */
  424. cmpwi 0,r4,0 /* mask != 0 ? */
  425. beq 4f
  426. and r3,r3,r4 /* IMMR & mask */
  427. 4:
  428. blr
  429. .globl get_pvr
  430. get_pvr:
  431. mfspr r3, PVR
  432. blr
  433. .globl wr_ic_cst
  434. wr_ic_cst:
  435. mtspr IC_CST, r3
  436. blr
  437. .globl rd_ic_cst
  438. rd_ic_cst:
  439. mfspr r3, IC_CST
  440. blr
  441. .globl wr_ic_adr
  442. wr_ic_adr:
  443. mtspr IC_ADR, r3
  444. blr
  445. .globl wr_dc_cst
  446. wr_dc_cst:
  447. mtspr DC_CST, r3
  448. blr
  449. .globl rd_dc_cst
  450. rd_dc_cst:
  451. mfspr r3, DC_CST
  452. blr
  453. .globl wr_dc_adr
  454. wr_dc_adr:
  455. mtspr DC_ADR, r3
  456. blr
  457. /*------------------------------------------------------------------------------*/
  458. /*
  459. * void relocate_code (addr_sp, gd, addr_moni)
  460. *
  461. * This "function" does not return, instead it continues in RAM
  462. * after relocating the monitor code.
  463. *
  464. * r3 = dest
  465. * r4 = src
  466. * r5 = length in bytes
  467. * r6 = cachelinesize
  468. */
  469. .globl relocate_code
  470. relocate_code:
  471. mr r1, r3 /* Set new stack pointer */
  472. mr r9, r4 /* Save copy of Global Data pointer */
  473. mr r10, r5 /* Save copy of Destination Address */
  474. mr r3, r5 /* Destination Address */
  475. lis r4, CFG_MONITOR_BASE@h /* Source Address */
  476. ori r4, r4, CFG_MONITOR_BASE@l
  477. lwz r5, GOT(__init_end)
  478. sub r5, r5, r4
  479. li r6, CFG_CACHELINE_SIZE /* Cache Line Size */
  480. /*
  481. * Fix GOT pointer:
  482. *
  483. * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address
  484. *
  485. * Offset:
  486. */
  487. sub r15, r10, r4
  488. /* First our own GOT */
  489. add r14, r14, r15
  490. /* then the one used by the C code */
  491. add r30, r30, r15
  492. /*
  493. * Now relocate code
  494. */
  495. cmplw cr1,r3,r4
  496. addi r0,r5,3
  497. srwi. r0,r0,2
  498. beq cr1,4f /* In place copy is not necessary */
  499. beq 7f /* Protect against 0 count */
  500. mtctr r0
  501. bge cr1,2f
  502. la r8,-4(r4)
  503. la r7,-4(r3)
  504. 1: lwzu r0,4(r8)
  505. stwu r0,4(r7)
  506. bdnz 1b
  507. b 4f
  508. 2: slwi r0,r0,2
  509. add r8,r4,r0
  510. add r7,r3,r0
  511. 3: lwzu r0,-4(r8)
  512. stwu r0,-4(r7)
  513. bdnz 3b
  514. /*
  515. * Now flush the cache: note that we must start from a cache aligned
  516. * address. Otherwise we might miss one cache line.
  517. */
  518. 4: cmpwi r6,0
  519. add r5,r3,r5
  520. beq 7f /* Always flush prefetch queue in any case */
  521. subi r0,r6,1
  522. andc r3,r3,r0
  523. mr r4,r3
  524. 5: dcbst 0,r4
  525. add r4,r4,r6
  526. cmplw r4,r5
  527. blt 5b
  528. sync /* Wait for all dcbst to complete on bus */
  529. mr r4,r3
  530. 6: icbi 0,r4
  531. add r4,r4,r6
  532. cmplw r4,r5
  533. blt 6b
  534. 7: sync /* Wait for all icbi to complete on bus */
  535. isync
  536. /*
  537. * We are done. Do not return, instead branch to second part of board
  538. * initialization, now running from RAM.
  539. */
  540. addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET
  541. mtlr r0
  542. blr
  543. in_ram:
  544. /*
  545. * Relocation Function, r14 point to got2+0x8000
  546. *
  547. * Adjust got2 pointers, no need to check for 0, this code
  548. * already puts a few entries in the table.
  549. */
  550. li r0,__got2_entries@sectoff@l
  551. la r3,GOT(_GOT2_TABLE_)
  552. lwz r11,GOT(_GOT2_TABLE_)
  553. mtctr r0
  554. sub r11,r3,r11
  555. addi r3,r3,-4
  556. 1: lwzu r0,4(r3)
  557. add r0,r0,r11
  558. stw r0,0(r3)
  559. bdnz 1b
  560. /*
  561. * Now adjust the fixups and the pointers to the fixups
  562. * in case we need to move ourselves again.
  563. */
  564. 2: li r0,__fixup_entries@sectoff@l
  565. lwz r3,GOT(_FIXUP_TABLE_)
  566. cmpwi r0,0
  567. mtctr r0
  568. addi r3,r3,-4
  569. beq 4f
  570. 3: lwzu r4,4(r3)
  571. lwzux r0,r4,r11
  572. add r0,r0,r11
  573. stw r10,0(r3)
  574. stw r0,0(r4)
  575. bdnz 3b
  576. 4:
  577. clear_bss:
  578. /*
  579. * Now clear BSS segment
  580. */
  581. lwz r3,GOT(__bss_start)
  582. #if defined(CONFIG_FADS) || defined(CONFIG_ICU862)
  583. /*
  584. * For the FADS - the environment is the very last item in flash.
  585. * The real .bss stops just before environment starts, so only
  586. * clear up to that point.
  587. */
  588. lwz r4,GOT(environment)
  589. #else
  590. lwz r4,GOT(_end)
  591. #endif
  592. cmplw 0, r3, r4
  593. beq 6f
  594. li r0, 0
  595. 5:
  596. stw r0, 0(r3)
  597. addi r3, r3, 4
  598. cmplw 0, r3, r4
  599. bne 5b
  600. 6:
  601. mr r3, r9 /* Global Data pointer */
  602. mr r4, r10 /* Destination Address */
  603. bl board_init_r
  604. /*
  605. * Copy exception vector code to low memory
  606. *
  607. * r3: dest_addr
  608. * r7: source address, r8: end address, r9: target address
  609. */
  610. .globl trap_init
  611. trap_init:
  612. lwz r7, GOT(_start)
  613. lwz r8, GOT(_end_of_vectors)
  614. li r9, 0x100 /* reset vector always at 0x100 */
  615. cmplw 0, r7, r8
  616. bgelr /* return if r7>=r8 - just in case */
  617. mflr r4 /* save link register */
  618. 1:
  619. lwz r0, 0(r7)
  620. stw r0, 0(r9)
  621. addi r7, r7, 4
  622. addi r9, r9, 4
  623. cmplw 0, r7, r8
  624. bne 1b
  625. /*
  626. * relocate `hdlr' and `int_return' entries
  627. */
  628. li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET
  629. li r8, Alignment - _start + EXC_OFF_SYS_RESET
  630. 2:
  631. bl trap_reloc
  632. addi r7, r7, 0x100 /* next exception vector */
  633. cmplw 0, r7, r8
  634. blt 2b
  635. li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET
  636. bl trap_reloc
  637. li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET
  638. bl trap_reloc
  639. li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET
  640. li r8, SystemCall - _start + EXC_OFF_SYS_RESET
  641. 3:
  642. bl trap_reloc
  643. addi r7, r7, 0x100 /* next exception vector */
  644. cmplw 0, r7, r8
  645. blt 3b
  646. li r7, .L_SingleStep - _start + EXC_OFF_SYS_RESET
  647. li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET
  648. 4:
  649. bl trap_reloc
  650. addi r7, r7, 0x100 /* next exception vector */
  651. cmplw 0, r7, r8
  652. blt 4b
  653. mtlr r4 /* restore link register */
  654. blr
  655. /*
  656. * Function: relocate entries for one exception vector
  657. */
  658. trap_reloc:
  659. lwz r0, 0(r7) /* hdlr ... */
  660. add r0, r0, r3 /* ... += dest_addr */
  661. stw r0, 0(r7)
  662. lwz r0, 4(r7) /* int_return ... */
  663. add r0, r0, r3 /* ... += dest_addr */
  664. stw r0, 4(r7)
  665. sync
  666. isync
  667. blr