2 * armboot - Startup Code for ARM720 CPU-core
4 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
5 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
7 * See file CREDITS for list of people who contributed to this
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 #include <asm-offsets.h>
29 #include <asm/hardware.h>
32 *************************************************************************
34 * Jump vector table as in table 3.1 in [1]
36 *************************************************************************
42 ldr pc, _undefined_instruction
43 ldr pc, _software_interrupt
44 ldr pc, _prefetch_abort
50 #ifdef CONFIG_SPL_BUILD
51 _undefined_instruction: .word _undefined_instruction
52 _software_interrupt: .word _software_interrupt
53 _prefetch_abort: .word _prefetch_abort
54 _data_abort: .word _data_abort
55 _not_used: .word _not_used
58 _pad: .word 0x12345678 /* now 16*4=64 */
60 _undefined_instruction: .word undefined_instruction
61 _software_interrupt: .word software_interrupt
62 _prefetch_abort: .word prefetch_abort
63 _data_abort: .word data_abort
64 _not_used: .word not_used
67 _pad: .word 0x12345678 /* now 16*4=64 */
68 #endif /* CONFIG_SPL_BUILD */
70 .balignl 16,0xdeadbeef
74 *************************************************************************
76 * Startup Code (reset vector)
78 * do important init only if we don't start from RAM!
79 * relocate armboot to ram
81 * jump to second stage
83 *************************************************************************
88 #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
89 .word CONFIG_SPL_TEXT_BASE
91 .word CONFIG_SYS_TEXT_BASE
95 * These are defined in the board-specific linker script.
96 * Subtracting _start from them lets the linker put their
97 * relative position in the executable instead of leaving
100 .globl _bss_start_ofs
102 .word __bss_start - _start
106 .word __bss_end - _start
112 #ifdef CONFIG_USE_IRQ
113 /* IRQ stack memory (calculated at run-time) */
114 .globl IRQ_STACK_START
118 /* IRQ stack memory (calculated at run-time) */
119 .globl FIQ_STACK_START
124 /* IRQ stack memory (calculated at run-time) + 8 bytes */
125 .globl IRQ_STACK_START_IN
130 * the actual reset code
135 * set the cpu to SVC32 mode
143 * we do sys-critical inits only at reboot,
144 * not when booting from ram!
146 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
152 /*------------------------------------------------------------------------------*/
154 #ifndef CONFIG_SPL_BUILD
156 * void relocate_code(addr_moni)
158 * This function relocates the monitor code.
162 mov r6, r0 /* save addr of destination */
165 subs r9, r6, r0 /* r9 <- relocation offset */
166 beq relocate_done /* skip relocation */
167 mov r1, r6 /* r1 <- scratch for copy_loop */
168 ldr r3, _image_copy_end_ofs
169 add r2, r0, r3 /* r2 <- source end address */
172 ldmia r0!, {r10-r11} /* copy from source address [r0] */
173 stmia r1!, {r10-r11} /* copy to target address [r1] */
174 cmp r0, r2 /* until source end address [r2] */
178 * fix .rel.dyn relocations
180 ldr r0, _TEXT_BASE /* r0 <- Text base */
181 ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */
182 add r10, r10, r0 /* r10 <- sym table in FLASH */
183 ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */
184 add r2, r2, r0 /* r2 <- rel dyn start in FLASH */
185 ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */
186 add r3, r3, r0 /* r3 <- rel dyn end in FLASH */
188 ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */
189 add r0, r0, r9 /* r0 <- location to fix up in RAM */
192 cmp r7, #23 /* relative fixup? */
194 cmp r7, #2 /* absolute fixup? */
196 /* ignore unknown type of fixup */
199 /* absolute fix: set location to (offset) symbol value */
200 mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */
201 add r1, r10, r1 /* r1 <- address of symbol in table */
202 ldr r1, [r1, #4] /* r1 <- symbol value */
203 add r1, r1, r9 /* r1 <- relocated sym addr */
206 /* relative fix: increase location by offset */
211 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
220 .word __image_copy_end - _start
222 .word __rel_dyn_start - _start
224 .word __rel_dyn_end - _start
226 .word __dynsym_start - _start
230 .globl c_runtime_cpu_setup
236 *************************************************************************
238 * CPU_init_critical registers
240 * setup important registers
241 * setup memory timing
243 *************************************************************************
246 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
251 * before relocating, we have to setup RAM timing
252 * because memory timing is board-dependent, you will
253 * find a lowlevel_init.S in your board directory.
259 #endif /* CONFIG_SKIP_LOWLEVEL_INIT */
262 #ifndef CONFIG_SPL_BUILD
264 *************************************************************************
268 *************************************************************************
274 #define S_FRAME_SIZE 72
296 #define MODE_SVC 0x13
300 * use bad_save_user_regs for abort/prefetch/undef/swi ...
301 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
304 .macro bad_save_user_regs
305 sub sp, sp, #S_FRAME_SIZE
306 stmia sp, {r0 - r12} @ Calling r0-r12
309 ldr r2, IRQ_STACK_START_IN
310 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
311 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
315 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
319 .macro irq_save_user_regs
320 sub sp, sp, #S_FRAME_SIZE
321 stmia sp, {r0 - r12} @ Calling r0-r12
323 stmdb r8, {sp, lr}^ @ Calling SP, LR
324 str lr, [r8, #0] @ Save calling PC
326 str r6, [r8, #4] @ Save CPSR
327 str r0, [r8, #8] @ Save OLD_R0
331 .macro irq_restore_user_regs
332 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
334 ldr lr, [sp, #S_PC] @ Get PC
335 add sp, sp, #S_FRAME_SIZE
336 subs pc, lr, #4 @ return & move spsr_svc into cpsr
340 ldr r13, IRQ_STACK_START_IN @ setup our mode stack
342 str lr, [r13] @ save caller lr / spsr
346 mov r13, #MODE_SVC @ prepare SVC-Mode
352 .macro get_irq_stack @ setup IRQ stack
353 ldr sp, IRQ_STACK_START
356 .macro get_fiq_stack @ setup FIQ stack
357 ldr sp, FIQ_STACK_START
364 undefined_instruction:
367 bl do_undefined_instruction
373 bl do_software_interrupt
393 #ifdef CONFIG_USE_IRQ
400 irq_restore_user_regs
405 /* someone ought to write a more effiction fiq_save_user_regs */
408 irq_restore_user_regs
425 #endif /* CONFIG_SPL_BUILD */