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 *************************************************************************
42 *************************************************************************
48 ldr pc, _undefined_instruction
49 ldr pc, _software_interrupt
50 ldr pc, _prefetch_abort
56 _undefined_instruction:
57 .word undefined_instruction
59 .word software_interrupt
71 .balignl 16,0xdeadbeef
74 *************************************************************************
76 * Startup Code (reset vector)
78 * do important init only if we don't start from memory!
79 * setup memory and board specific bits prior to relocation.
80 * relocate armboot to ram
83 *************************************************************************
88 .word TEXT_BASE /* address of _start in the linked image */
90 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
97 * These are defined in the board-specific linker script.
107 #ifdef CONFIG_USE_IRQ
108 /* IRQ stack memory (calculated at run-time) */
109 .globl IRQ_STACK_START
113 /* IRQ stack memory (calculated at run-time) */
114 .globl FIQ_STACK_START
119 #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
120 /* IRQ stack memory (calculated at run-time) + 8 bytes */
121 .globl IRQ_STACK_START_IN
125 .globl _datarel_start
127 .word __datarel_start
129 .globl _datarelrolocal_start
130 _datarelrolocal_start:
131 .word __datarelrolocal_start
133 .globl _datarellocal_start
135 .word __datarellocal_start
137 .globl _datarelro_start
139 .word __datarelro_start
150 * the actual reset code
155 * set the cpu to SVC32 mode
163 * we do sys-critical inits only at reboot,
164 * not when booting from ram!
166 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
170 /* Set stackpointer in internal RAM to call board_init_f */
172 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
176 /*------------------------------------------------------------------------------*/
179 * void relocate_code (addr_sp, gd, addr_moni)
181 * This "function" does not return, instead it continues in RAM
182 * after relocating the monitor code.
187 mov r4, r0 /* save addr_sp */
188 mov r5, r1 /* save addr of gd */
189 mov r6, r2 /* save addr of destination */
190 mov r7, r2 /* save addr of destination */
192 /* Set up the stack */
199 sub r2, r3, r2 /* r2 <- size of armboot */
200 add r2, r0, r2 /* r2 <- source end address */
204 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
206 ldmia r0!, {r9-r10} /* copy from source address [r0] */
207 stmia r6!, {r9-r10} /* copy to target address [r1] */
208 cmp r0, r2 /* until source end address [r2] */
211 #ifndef CONFIG_PRELOADER
212 /* fix got entries */
213 ldr r1, _TEXT_BASE /* Text base */
214 mov r0, r7 /* reloc addr */
215 ldr r2, _got_start /* addr in Flash */
216 ldr r3, _got_end /* addr in Flash */
231 #endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
234 #ifndef CONFIG_PRELOADER
237 ldr r3, _TEXT_BASE /* Text base */
238 mov r4, r7 /* reloc addr */
243 mov r2, #0x00000000 /* clear */
245 clbss_l:str r2, [r0] /* clear loop... */
255 * We are done. Do not return, instead branch to second part of board
256 * initialization, now running from RAM.
259 ldr r2, _board_init_r
261 add r2, r2, r7 /* position from board_init_r in RAM */
262 /* setup parameters for board_init_r */
263 mov r0, r5 /* gd_t */
264 mov r1, r7 /* dest_addr */
269 _board_init_r: .word board_init_r
271 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
274 * the actual reset code
279 * set the cpu to SVC32 mode
287 * we do sys-critical inits only at reboot,
288 * not when booting from ram!
290 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
294 relocate: /* relocate U-Boot to RAM */
295 adr r0, _start /* pc relative address of label */
296 ldr r1, _TEXT_BASE /* linked image address of label */
297 cmp r0, r1 /* test if we run from flash or RAM */
298 beq stack_setup /* ifeq we are in the RAM copy */
300 ldr r2, _armboot_start
302 sub r2, r3, r2 /* r2 <- size of armboot */
303 add r2, r0, r2 /* r2 <- source end address */
306 ldmia r0!, {r3-r10} /* copy from source address [r0] */
307 stmia r1!, {r3-r10} /* copy to target address [r1] */
308 cmp r0, r2 /* until source end address [r2] */
311 /* Set up the stack */
313 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
314 sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
315 sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
316 #ifdef CONFIG_USE_IRQ
317 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
319 sub sp, r0, #12 /* leave 3 words for abort-stack */
320 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
323 ldr r0, _bss_start /* find start of bss segment */
324 ldr r1, _bss_end /* stop here */
325 mov r2, #0x00000000 /* clear */
327 clbss_l:str r2, [r0] /* clear loop... */
332 ldr pc, _start_armboot
337 #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
340 *************************************************************************
342 * CPU_init_critical registers
344 * setup important registers
345 * setup memory timing
347 *************************************************************************
350 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
352 /* arm_int_generic assumes the ARM boot monitor, or user software,
353 * has initialized the platform
355 mov pc, lr /* back to my caller */
358 *************************************************************************
362 *************************************************************************
368 #define S_FRAME_SIZE 72
390 #define MODE_SVC 0x13
394 * use bad_save_user_regs for abort/prefetch/undef/swi ...
395 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
398 .macro bad_save_user_regs
399 @ carve out a frame on current user stack
400 sub sp, sp, #S_FRAME_SIZE
401 stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
403 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
404 ldr r2, _armboot_start
405 sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
406 sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
408 ldr r2, IRQ_STACK_START_IN
410 @ get values for "aborted" pc and cpsr (into parm regs)
412 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
415 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
416 mov r0, sp @ save current stack into r0 (param register)
419 .macro irq_save_user_regs
420 sub sp, sp, #S_FRAME_SIZE
421 stmia sp, {r0 - r12} @ Calling r0-r12
422 @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
424 stmdb r8, {sp, lr}^ @ Calling SP, LR
425 str lr, [r8, #0] @ Save calling PC
427 str r6, [r8, #4] @ Save CPSR
428 str r0, [r8, #8] @ Save OLD_R0
432 .macro irq_restore_user_regs
433 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
435 ldr lr, [sp, #S_PC] @ Get PC
436 add sp, sp, #S_FRAME_SIZE
437 subs pc, lr, #4 @ return & move spsr_svc into cpsr
441 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
442 ldr r13, _armboot_start @ setup our mode stack
443 sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
444 sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
446 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
449 str lr, [r13] @ save caller lr in position 0 of saved stack
450 mrs lr, spsr @ get the spsr
451 str lr, [r13, #4] @ save spsr in position 1 of saved stack
452 mov r13, #MODE_SVC @ prepare SVC-Mode
454 msr spsr, r13 @ switch modes, make sure moves will execute
455 mov lr, pc @ capture return pc
456 movs pc, lr @ jump to next instruction & switch modes.
459 .macro get_irq_stack @ setup IRQ stack
460 ldr sp, IRQ_STACK_START
463 .macro get_fiq_stack @ setup FIQ stack
464 ldr sp, FIQ_STACK_START
471 .globl undefined_instruction
472 undefined_instruction:
475 bl do_undefined_instruction
478 .globl software_interrupt
482 bl do_software_interrupt
485 .globl prefetch_abort
505 #ifdef CONFIG_USE_IRQ
512 irq_restore_user_regs
518 /* someone ought to write a more effiction fiq_save_user_regs */
521 irq_restore_user_regs