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,
33 *************************************************************************
35 * Jump vector table as in table 3.1 in [1]
37 *************************************************************************
43 ldr pc, _undefined_instruction
44 ldr pc, _software_interrupt
45 ldr pc, _prefetch_abort
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
59 .balignl 16,0xdeadbeef
63 *************************************************************************
65 * Startup Code (reset vector)
67 * do important init only if we don't start from memory!
68 * relocate armboot to ram
70 * jump to second stage
72 *************************************************************************
76 * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
86 * Note: _armboot_end_data and _armboot_end are defined
87 * by the (board-dependent) linker script.
88 * _armboot_end_data is the first usable FLASH address after armboot
90 .globl _armboot_end_data
92 .word armboot_end_data
94 * Note: armboot_end is defined by the (board-dependent) linker script
101 * _armboot_real_end is the first usable RAM address behind armboot
102 * and the various stacks
104 .globl _armboot_real_end
108 #ifdef CONFIG_USE_IRQ
109 /* IRQ stack memory (calculated at run-time) */
110 .globl IRQ_STACK_START
114 /* IRQ stack memory (calculated at run-time) */
115 .globl FIQ_STACK_START
122 * the actual reset code
127 * set the cpu to SVC32 mode
135 * relocate exeception table
147 * we do sys-critical inits only at reboot,
148 * not when booting from ram!
150 #ifdef CONFIG_INIT_CRITICAL
154 /* set up the stack */
156 add r0, r0, #CONFIG_STACKSIZE
157 sub sp, r0, #12 /* leave 3 words for abort-stack */
158 ldr pc,_start_armboot
160 _start_armboot: .word start_armboot
163 *************************************************************************
165 * CPU_init_critical registers
167 *************************************************************************
171 # actually do nothing for now!
178 *************************************************************************
182 *************************************************************************
188 #define S_FRAME_SIZE 72
210 #define MODE_SVC 0x13
214 * use bad_save_user_regs for abort/prefetch/undef/swi ...
215 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
218 .macro bad_save_user_regs
219 sub sp, sp, #S_FRAME_SIZE
220 stmia sp, {r0 - r12} @ Calling r0-r12
224 add r2, r2, #CONFIG_STACKSIZE
226 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
227 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
231 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
235 .macro irq_save_user_regs
236 sub sp, sp, #S_FRAME_SIZE
237 stmia sp, {r0 - r12} @ Calling r0-r12
239 stmdb r8, {sp, lr}^ @ Calling SP, LR
240 str lr, [r8, #0] @ Save calling PC
242 str r6, [r8, #4] @ Save CPSR
243 str r0, [r8, #8] @ Save OLD_R0
247 .macro irq_restore_user_regs
248 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
250 ldr lr, [sp, #S_PC] @ Get PC
251 add sp, sp, #S_FRAME_SIZE
252 subs pc, lr, #4 @ return & move spsr_svc into cpsr
256 ldr r13, _armboot_end @ setup our mode stack
257 add r13, r13, #CONFIG_STACKSIZE @ resides at top of normal stack
260 str lr, [r13] @ save caller lr / spsr
264 mov r13, #MODE_SVC @ prepare SVC-Mode
270 .macro get_irq_stack @ setup IRQ stack
271 ldr sp, IRQ_STACK_START
274 .macro get_fiq_stack @ setup FIQ stack
275 ldr sp, FIQ_STACK_START
282 undefined_instruction:
285 bl do_undefined_instruction
291 bl do_software_interrupt
311 #ifdef CONFIG_USE_IRQ
318 irq_restore_user_regs
323 /* someone ought to write a more effiction fiq_save_user_regs */
326 irq_restore_user_regs