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,
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 _undefined_instruction: .word undefined_instruction
51 _software_interrupt: .word software_interrupt
52 _prefetch_abort: .word prefetch_abort
53 _data_abort: .word data_abort
54 _not_used: .word not_used
58 .balignl 16,0xdeadbeef
62 *************************************************************************
64 * Startup Code (reset vector)
66 * do important init only if we don't start from memory!
67 * relocate armboot to ram
69 * jump to second stage
71 *************************************************************************
82 * Note: _armboot_end_data and _armboot_end are defined
83 * by the (board-dependent) linker script.
84 * _armboot_end_data is the first usable FLASH address after armboot
86 .globl _armboot_end_data
88 .word armboot_end_data
90 * Note: armboot_end is defined by the (board-dependent) linker script
97 /* IRQ stack memory (calculated at run-time) */
98 .globl IRQ_STACK_START
102 /* IRQ stack memory (calculated at run-time) */
103 .globl FIQ_STACK_START
110 * the actual reset code
115 * set the cpu to SVC32 mode
123 * relocate exeception table
135 * we do sys-critical inits only at reboot,
136 * not when booting from ram!
138 #ifdef CONFIG_INIT_CRITICAL
142 /* Set up the stack */
144 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
145 sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
146 sub r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo */
147 #ifdef CONFIG_USE_IRQ
148 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
150 sub sp, r0, #12 /* leave 3 words for abort-stack */
152 ldr pc,_start_armboot
154 _start_armboot: .word start_armboot
157 *************************************************************************
159 * CPU_init_critical registers
161 *************************************************************************
165 # actually do nothing for now!
170 *************************************************************************
174 *************************************************************************
180 #define S_FRAME_SIZE 72
202 #define MODE_SVC 0x13
206 * use bad_save_user_regs for abort/prefetch/undef/swi ...
207 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
210 .macro bad_save_user_regs
211 sub sp, sp, #S_FRAME_SIZE
212 stmia sp, {r0 - r12} @ Calling r0-r12
216 add r2, r2, #CONFIG_STACKSIZE
218 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
219 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
223 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
227 .macro irq_save_user_regs
228 sub sp, sp, #S_FRAME_SIZE
229 stmia sp, {r0 - r12} @ Calling r0-r12
231 stmdb r8, {sp, lr}^ @ Calling SP, LR
232 str lr, [r8, #0] @ Save calling PC
234 str r6, [r8, #4] @ Save CPSR
235 str r0, [r8, #8] @ Save OLD_R0
239 .macro irq_restore_user_regs
240 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
242 ldr lr, [sp, #S_PC] @ Get PC
243 add sp, sp, #S_FRAME_SIZE
244 subs pc, lr, #4 @ return & move spsr_svc into cpsr
248 ldr r13, _armboot_end @ setup our mode stack
249 add r13, r13, #CONFIG_STACKSIZE @ resides at top of normal stack
252 str lr, [r13] @ save caller lr / spsr
256 mov r13, #MODE_SVC @ prepare SVC-Mode
262 .macro get_irq_stack @ setup IRQ stack
263 ldr sp, IRQ_STACK_START
266 .macro get_fiq_stack @ setup FIQ stack
267 ldr sp, FIQ_STACK_START
274 undefined_instruction:
277 bl do_undefined_instruction
283 bl do_software_interrupt
303 #ifdef CONFIG_USE_IRQ
310 irq_restore_user_regs
315 /* someone ought to write a more effiction fiq_save_user_regs */
318 irq_restore_user_regs