2 * armboot - Startup Code for SA1100 CPU
4 * Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
5 * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
6 * Copyright (C) 2000 Wolfgang Denk <wd@denx.de>
7 * Copyright (c) 2001 Alex Züpke <azu@sysgo.de>
9 * See file CREDITS for list of people who contributed to this
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
34 *************************************************************************
36 * Jump vector table as in table 3.1 in [1]
38 *************************************************************************
44 ldr pc, _undefined_instruction
45 ldr pc, _software_interrupt
46 ldr pc, _prefetch_abort
52 _undefined_instruction: .word undefined_instruction
53 _software_interrupt: .word software_interrupt
54 _prefetch_abort: .word prefetch_abort
55 _data_abort: .word data_abort
56 _not_used: .word not_used
60 .balignl 16,0xdeadbeef
64 *************************************************************************
66 * Startup Code (reset vector)
68 * do important init only if we don't start from memory!
69 * relocate armboot to ram
71 * jump to second stage
73 *************************************************************************
80 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
87 * These are defined in the board-specific linker script.
98 /* IRQ stack memory (calculated at run-time) */
99 .globl IRQ_STACK_START
103 /* IRQ stack memory (calculated at run-time) */
104 .globl FIQ_STACK_START
109 #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
110 /* IRQ stack memory (calculated at run-time) + 8 bytes */
111 .globl IRQ_STACK_START_IN
115 .globl _datarel_start
117 .word __datarel_start
119 .globl _datarelrolocal_start
120 _datarelrolocal_start:
121 .word __datarelrolocal_start
123 .globl _datarellocal_start
125 .word __datarellocal_start
127 .globl _datarelro_start
129 .word __datarelro_start
140 * the actual reset code
145 * set the cpu to SVC32 mode
153 * we do sys-critical inits only at reboot,
154 * not when booting from ram!
156 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
160 /* Set stackpointer in internal RAM to call board_init_f */
162 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
166 /*------------------------------------------------------------------------------*/
169 * void relocate_code (addr_sp, gd, addr_moni)
171 * This "function" does not return, instead it continues in RAM
172 * after relocating the monitor code.
177 mov r4, r0 /* save addr_sp */
178 mov r5, r1 /* save addr of gd */
179 mov r6, r2 /* save addr of destination */
180 mov r7, r2 /* save addr of destination */
182 /* Set up the stack */
189 sub r2, r3, r2 /* r2 <- size of armboot */
190 add r2, r0, r2 /* r2 <- source end address */
194 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
196 ldmia r0!, {r9-r10} /* copy from source address [r0] */
197 stmia r6!, {r9-r10} /* copy to target address [r1] */
198 cmp r0, r2 /* until source end address [r2] */
201 #ifndef CONFIG_PRELOADER
202 /* fix got entries */
203 ldr r1, _TEXT_BASE /* Text base */
204 mov r0, r7 /* reloc addr */
205 ldr r2, _got_start /* addr in Flash */
206 ldr r3, _got_end /* addr in Flash */
221 #endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
224 #ifndef CONFIG_PRELOADER
227 ldr r3, _TEXT_BASE /* Text base */
228 mov r4, r7 /* reloc addr */
233 mov r2, #0x00000000 /* clear */
235 clbss_l:str r2, [r0] /* clear loop... */
242 * We are done. Do not return, instead branch to second part of board
243 * initialization, now running from RAM.
246 ldr r2, _board_init_r
248 add r2, r2, r7 /* position from board_init_r in RAM */
249 /* setup parameters for board_init_r */
250 mov r0, r5 /* gd_t */
251 mov r1, r7 /* dest_addr */
256 _board_init_r: .word board_init_r
258 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
261 * the actual reset code
266 * set the cpu to SVC32 mode
274 * we do sys-critical inits only at reboot,
275 * not when booting from ram!
277 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
281 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
282 relocate: /* relocate U-Boot to RAM */
283 adr r0, _start /* r0 <- current position of code */
284 ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
285 cmp r0, r1 /* don't reloc during debug */
288 ldr r2, _armboot_start
290 sub r2, r3, r2 /* r2 <- size of armboot */
291 add r2, r0, r2 /* r2 <- source end address */
294 ldmia r0!, {r3-r10} /* copy from source address [r0] */
295 stmia r1!, {r3-r10} /* copy to target address [r1] */
296 cmp r0, r2 /* until source end address [r2] */
298 #endif /* CONFIG_SKIP_RELOCATE_UBOOT */
300 /* Set up the stack */
302 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
303 sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
304 sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
305 #ifdef CONFIG_USE_IRQ
306 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
308 sub sp, r0, #12 /* leave 3 words for abort-stack */
309 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
312 ldr r0, _bss_start /* find start of bss segment */
313 ldr r1, _bss_end /* stop here */
314 mov r2, #0x00000000 /* clear */
316 clbss_l:str r2, [r0] /* clear loop... */
321 ldr pc, _start_armboot
323 _start_armboot: .word start_armboot
325 #endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
328 *************************************************************************
330 * CPU_init_critical registers
332 * setup important registers
333 * setup memory timing
335 *************************************************************************
339 /* Interupt-Controller base address */
340 IC_BASE: .word 0x90050000
344 /* Reset-Controller */
345 RST_BASE: .word 0x90030000
351 PWR_BASE: .word 0x90020000
354 cpuspeed: .word CONFIG_SYS_CPUSPEED
365 /* set clock speed */
371 * before relocating, we have to setup RAM timing
372 * because memory timing is board-dependend, you will
373 * find a lowlevel_init.S in your board directory.
380 * disable MMU stuff and enable I-cache
383 bic r0, r0, #0x00002000 @ clear bit 13 (X)
384 bic r0, r0, #0x0000000f @ clear bits 3-0 (WCAM)
385 orr r0, r0, #0x00001000 @ set bit 12 (I) Icache
386 orr r0, r0, #0x00000002 @ set bit 2 (A) Align
390 * flush v4 I/D caches
393 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
394 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
400 *************************************************************************
404 *************************************************************************
410 #define S_FRAME_SIZE 72
432 #define MODE_SVC 0x13
436 * use bad_save_user_regs for abort/prefetch/undef/swi ...
437 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
440 .macro bad_save_user_regs
441 sub sp, sp, #S_FRAME_SIZE
442 stmia sp, {r0 - r12} @ Calling r0-r12
445 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
446 ldr r2, _armboot_start
447 sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
448 sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
450 ldr r2, IRQ_STACK_START_IN
452 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
453 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
457 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
461 .macro irq_save_user_regs
462 sub sp, sp, #S_FRAME_SIZE
463 stmia sp, {r0 - r12} @ Calling r0-r12
465 stmdb r8, {sp, lr}^ @ Calling SP, LR
466 str lr, [r8, #0] @ Save calling PC
468 str r6, [r8, #4] @ Save CPSR
469 str r0, [r8, #8] @ Save OLD_R0
473 .macro irq_restore_user_regs
474 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
476 ldr lr, [sp, #S_PC] @ Get PC
477 add sp, sp, #S_FRAME_SIZE
478 subs pc, lr, #4 @ return & move spsr_svc into cpsr
482 #if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
483 ldr r13, _armboot_start @ setup our mode stack
484 sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
485 sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
487 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
490 str lr, [r13] @ save caller lr / spsr
494 mov r13, #MODE_SVC @ prepare SVC-Mode
500 .macro get_irq_stack @ setup IRQ stack
501 ldr sp, IRQ_STACK_START
504 .macro get_fiq_stack @ setup FIQ stack
505 ldr sp, FIQ_STACK_START
512 undefined_instruction:
515 bl do_undefined_instruction
521 bl do_software_interrupt
541 #ifdef CONFIG_USE_IRQ
548 irq_restore_user_regs
553 /* someone ought to write a more effiction fiq_save_user_regs */
556 irq_restore_user_regs
578 mov r1, #0x0 @ set bit 3-0 ...
579 str r1, [r0, #RCSR] @ ... to clear in RCSR
581 str r1, [r0, #RSRR] @ and perform reset
582 b reset_cpu @ silly, but repeat endlessly