2 * armboot - Startup Code for ARM926EJS CPU-core
4 * Copyright (c) 2003 Texas Instruments
6 * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
8 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
9 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
10 * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
11 * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
12 * Copyright (c) 2003 Kshitij <kshitij@ti.com>
14 * See file CREDITS for list of people who contributed to this
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
38 #if defined(CONFIG_OMAP1610)
39 #include <./configs/omap1510.h>
40 #elif defined(CONFIG_OMAP730)
41 #include <./configs/omap730.h>
45 *************************************************************************
47 * Jump vector table as in table 3.1 in [1]
49 *************************************************************************
56 #ifdef CONFIG_PRELOADER
57 /* No exception handlers in preloader */
68 /* pad to 64 byte boundary */
77 ldr pc, _undefined_instruction
78 ldr pc, _software_interrupt
79 ldr pc, _prefetch_abort
85 _undefined_instruction:
86 .word undefined_instruction
88 .word software_interrupt
100 #endif /* CONFIG_PRELOADER */
101 .balignl 16,0xdeadbeef
105 *************************************************************************
107 * Startup Code (reset vector)
109 * do important init only if we don't start from memory!
110 * setup Memory and board specific bits prior to relocation.
111 * relocate armboot to ram
114 *************************************************************************
119 .word CONFIG_SYS_TEXT_BASE
121 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
122 .globl _armboot_start
128 * These are defined in the board-specific linker script.
138 #ifdef CONFIG_USE_IRQ
139 /* IRQ stack memory (calculated at run-time) */
140 .globl IRQ_STACK_START
144 /* IRQ stack memory (calculated at run-time) */
145 .globl FIQ_STACK_START
150 #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
151 /* IRQ stack memory (calculated at run-time) + 8 bytes */
152 .globl IRQ_STACK_START_IN
156 .globl _datarel_start
158 .word __datarel_start
160 .globl _datarelrolocal_start
161 _datarelrolocal_start:
162 .word __datarelrolocal_start
164 .globl _datarellocal_start
166 .word __datarellocal_start
168 .globl _datarelro_start
170 .word __datarelro_start
181 * the actual reset code
186 * set the cpu to SVC32 mode
194 * we do sys-critical inits only at reboot,
195 * not when booting from ram!
197 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
201 /* Set stackpointer in internal RAM to call board_init_f */
203 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
207 /*------------------------------------------------------------------------------*/
210 * void relocate_code (addr_sp, gd, addr_moni)
212 * This "function" does not return, instead it continues in RAM
213 * after relocating the monitor code.
218 mov r4, r0 /* save addr_sp */
219 mov r5, r1 /* save addr of gd */
220 mov r6, r2 /* save addr of destination */
221 mov r7, r2 /* save addr of destination */
223 /* Set up the stack */
230 sub r2, r3, r2 /* r2 <- size of armboot */
231 add r2, r0, r2 /* r2 <- source end address */
235 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
237 ldmia r0!, {r9-r10} /* copy from source address [r0] */
238 stmia r6!, {r9-r10} /* copy to target address [r1] */
239 cmp r0, r2 /* until source end address [r2] */
242 #ifndef CONFIG_PRELOADER
243 /* fix got entries */
244 ldr r1, _TEXT_BASE /* Text base */
245 mov r0, r7 /* reloc addr */
246 ldr r2, _got_start /* addr in Flash */
247 ldr r3, _got_end /* addr in Flash */
262 #endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
265 #ifndef CONFIG_PRELOADER
268 ldr r3, _TEXT_BASE /* Text base */
269 mov r4, r7 /* reloc addr */
274 mov r2, #0x00000000 /* clear */
276 clbss_l:str r2, [r0] /* clear loop... */
286 * We are done. Do not return, instead branch to second part of board
287 * initialization, now running from RAM.
289 #ifdef CONFIG_NAND_SPL
292 _nand_boot: .word nand_boot
295 ldr r2, _board_init_r
297 add r2, r2, r7 /* position from board_init_r in RAM */
298 /* setup parameters for board_init_r */
299 mov r0, r5 /* gd_t */
300 mov r1, r7 /* dest_addr */
305 _board_init_r: .word board_init_r
308 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
310 * the actual reset code
315 * set the cpu to SVC32 mode
323 * we do sys-critical inits only at reboot,
324 * not when booting from ram!
326 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
330 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
331 relocate: /* relocate U-Boot to RAM */
332 adr r0, _start /* r0 <- current position of code */
333 ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
334 cmp r0, r1 /* don't reloc during debug */
336 ldr r2, _armboot_start
338 sub r2, r3, r2 /* r2 <- size of armboot */
339 add r2, r0, r2 /* r2 <- source end address */
342 ldmia r0!, {r3-r10} /* copy from source address [r0] */
343 stmia r1!, {r3-r10} /* copy to target address [r1] */
344 cmp r0, r2 /* until source end address [r2] */
346 #endif /* CONFIG_SKIP_RELOCATE_UBOOT */
348 /* Set up the stack */
350 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
351 sub sp, r0, #128 /* leave 32 words for abort-stack */
352 #ifndef CONFIG_PRELOADER
353 sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
354 sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
355 #ifdef CONFIG_USE_IRQ
356 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
358 #endif /* CONFIG_PRELOADER */
359 sub sp, r0, #12 /* leave 3 words for abort-stack */
360 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
363 ldr r0, _bss_start /* find start of bss segment */
364 ldr r1, _bss_end /* stop here */
365 mov r2, #0x00000000 /* clear */
367 #ifndef CONFIG_PRELOADER
368 clbss_l:str r2, [r0] /* clear loop... */
375 #endif /* CONFIG_PRELOADER */
377 ldr pc, _start_armboot
380 #ifdef CONFIG_NAND_SPL
384 #endif /* CONFIG_NAND_SPL */
385 #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
388 *************************************************************************
390 * CPU_init_critical registers
392 * setup important registers
393 * setup memory timing
395 *************************************************************************
397 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
400 * flush v4 I/D caches
403 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
404 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
407 * disable MMU stuff and caches
409 mrc p15, 0, r0, c1, c0, 0
410 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
411 bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
412 orr r0, r0, #0x00000002 /* set bit 2 (A) Align */
413 orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
414 mcr p15, 0, r0, c1, c0, 0
417 * Go setup Memory and board specific bits prior to relocation.
419 mov ip, lr /* perserve link reg across call */
420 bl lowlevel_init /* go setup pll,mux,memory */
421 mov lr, ip /* restore link */
422 mov pc, lr /* back to my caller */
423 #endif /* CONFIG_SKIP_LOWLEVEL_INIT */
425 #ifndef CONFIG_PRELOADER
427 *************************************************************************
431 *************************************************************************
437 #define S_FRAME_SIZE 72
459 #define MODE_SVC 0x13
463 * use bad_save_user_regs for abort/prefetch/undef/swi ...
464 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
467 .macro bad_save_user_regs
468 @ carve out a frame on current user stack
469 sub sp, sp, #S_FRAME_SIZE
470 stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
471 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
472 ldr r2, _armboot_start
473 sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
474 sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
476 ldr r2, IRQ_STACK_START_IN
478 @ get values for "aborted" pc and cpsr (into parm regs)
480 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
483 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
484 mov r0, sp @ save current stack into r0 (param register)
487 .macro irq_save_user_regs
488 sub sp, sp, #S_FRAME_SIZE
489 stmia sp, {r0 - r12} @ Calling r0-r12
490 @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
492 stmdb r8, {sp, lr}^ @ Calling SP, LR
493 str lr, [r8, #0] @ Save calling PC
495 str r6, [r8, #4] @ Save CPSR
496 str r0, [r8, #8] @ Save OLD_R0
500 .macro irq_restore_user_regs
501 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
503 ldr lr, [sp, #S_PC] @ Get PC
504 add sp, sp, #S_FRAME_SIZE
505 subs pc, lr, #4 @ return & move spsr_svc into cpsr
509 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
510 ldr r13, _armboot_start @ setup our mode stack
511 sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
512 sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
514 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
517 str lr, [r13] @ save caller lr in position 0 of saved stack
518 mrs lr, spsr @ get the spsr
519 str lr, [r13, #4] @ save spsr in position 1 of saved stack
520 mov r13, #MODE_SVC @ prepare SVC-Mode
522 msr spsr, r13 @ switch modes, make sure moves will execute
523 mov lr, pc @ capture return pc
524 movs pc, lr @ jump to next instruction & switch modes.
527 .macro get_irq_stack @ setup IRQ stack
528 ldr sp, IRQ_STACK_START
531 .macro get_fiq_stack @ setup FIQ stack
532 ldr sp, FIQ_STACK_START
534 #endif /* CONFIG_PRELOADER */
539 #ifdef CONFIG_PRELOADER
542 ldr sp, _TEXT_BASE /* switch to abort stack */
544 bl 1b /* hang and never return */
545 #else /* !CONFIG_PRELOADER */
547 undefined_instruction:
550 bl do_undefined_instruction
556 bl do_software_interrupt
576 #ifdef CONFIG_USE_IRQ
583 irq_restore_user_regs
588 /* someone ought to write a more effiction fiq_save_user_regs */
591 irq_restore_user_regs
608 #endif /* CONFIG_PRELOADER */