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 * These are defined in the board-specific linker script.
93 /* IRQ stack memory (calculated at run-time) */
94 .globl IRQ_STACK_START
98 /* IRQ stack memory (calculated at run-time) */
99 .globl FIQ_STACK_START
106 * the actual reset code
111 * set the cpu to SVC32 mode
119 * relocate exeception table
131 * we do sys-critical inits only at reboot,
132 * not when booting from ram!
134 #ifdef CONFIG_INIT_CRITICAL
138 /* Set up the stack */
140 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
141 sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
142 sub r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo */
143 #ifdef CONFIG_USE_IRQ
144 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
146 sub sp, r0, #12 /* leave 3 words for abort-stack */
149 ldr r0, _bss_start /* find start of bss segment */
150 ldr r1, _bss_end /* stop here */
151 mov r2, #0x00000000 /* clear */
153 clbss_l:str r2, [r0] /* clear loop... */
158 ldr pc,_start_armboot
160 _start_armboot: .word start_armboot
163 *************************************************************************
165 * CPU_init_critical registers
167 *************************************************************************
171 # actually do nothing for now!
176 *************************************************************************
180 *************************************************************************
186 #define S_FRAME_SIZE 72
208 #define MODE_SVC 0x13
212 * use bad_save_user_regs for abort/prefetch/undef/swi ...
213 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
216 .macro bad_save_user_regs
217 sub sp, sp, #S_FRAME_SIZE
218 stmia sp, {r0 - r12} @ Calling r0-r12
221 ldr r2, _armboot_start
222 sub r2, r2, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
223 sub r2, r2, #(CFG_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
224 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
225 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
229 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
233 .macro irq_save_user_regs
234 sub sp, sp, #S_FRAME_SIZE
235 stmia sp, {r0 - r12} @ Calling r0-r12
237 stmdb r8, {sp, lr}^ @ Calling SP, LR
238 str lr, [r8, #0] @ Save calling PC
240 str r6, [r8, #4] @ Save CPSR
241 str r0, [r8, #8] @ Save OLD_R0
245 .macro irq_restore_user_regs
246 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
248 ldr lr, [sp, #S_PC] @ Get PC
249 add sp, sp, #S_FRAME_SIZE
250 subs pc, lr, #4 @ return & move spsr_svc into cpsr
254 ldr r13, _armboot_start @ setup our mode stack
255 sub r13, r13, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
256 sub r13, r13, #(CFG_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
258 str lr, [r13] @ save caller lr / spsr
262 mov r13, #MODE_SVC @ prepare SVC-Mode
268 .macro get_irq_stack @ setup IRQ stack
269 ldr sp, IRQ_STACK_START
272 .macro get_fiq_stack @ setup FIQ stack
273 ldr sp, FIQ_STACK_START
280 undefined_instruction:
283 bl do_undefined_instruction
289 bl do_software_interrupt
309 #ifdef CONFIG_USE_IRQ
316 irq_restore_user_regs
321 /* someone ought to write a more effiction fiq_save_user_regs */
324 irq_restore_user_regs