2 * armboot - Startup Code for ARM926EJS CPU-core
4 * Copyright (c) 2003 Texas Instruments
6 * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
8 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
9 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
10 * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
11 * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
12 * Copyright (c) 2003 Kshitij <kshitij@ti.com>
14 * See file CREDITS for list of people who contributed to this
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
38 #if defined(CONFIG_OMAP1610)
39 #include <./configs/omap1510.h>
40 #elif defined(CONFIG_OMAP730)
41 #include <./configs/omap730.h>
45 *************************************************************************
47 * Jump vector table as in table 3.1 in [1]
49 *************************************************************************
56 ldr pc, _undefined_instruction
57 ldr pc, _software_interrupt
58 ldr pc, _prefetch_abort
64 _undefined_instruction:
65 .word undefined_instruction
67 .word software_interrupt
79 .balignl 16,0xdeadbeef
83 *************************************************************************
85 * Startup Code (reset vector)
87 * do important init only if we don't start from memory!
88 * setup Memory and board specific bits prior to relocation.
89 * relocate armboot to ram
92 *************************************************************************
103 * These are defined in the board-specific linker script.
113 #ifdef CONFIG_USE_IRQ
114 /* IRQ stack memory (calculated at run-time) */
115 .globl IRQ_STACK_START
119 /* IRQ stack memory (calculated at run-time) */
120 .globl FIQ_STACK_START
127 * the actual reset code
132 * set the cpu to SVC32 mode
140 * we do sys-critical inits only at reboot,
141 * not when booting from ram!
143 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
147 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
148 relocate: /* relocate U-Boot to RAM */
149 adr r0, _start /* r0 <- current position of code */
150 ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
151 cmp r0, r1 /* don't reloc during debug */
154 ldr r2, _armboot_start
156 sub r2, r3, r2 /* r2 <- size of armboot */
157 add r2, r0, r2 /* r2 <- source end address */
160 ldmia r0!, {r3-r10} /* copy from source address [r0] */
161 stmia r1!, {r3-r10} /* copy to target address [r1] */
162 cmp r0, r2 /* until source end addreee [r2] */
164 #endif /* CONFIG_SKIP_RELOCATE_UBOOT */
166 /* Set up the stack */
168 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
169 sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
170 sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
171 #ifdef CONFIG_USE_IRQ
172 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
174 sub sp, r0, #12 /* leave 3 words for abort-stack */
175 bic sp, r0, #7 /* 8-byte align stack for ABI compliance */
178 ldr r0, _bss_start /* find start of bss segment */
179 ldr r1, _bss_end /* stop here */
180 mov r2, #0x00000000 /* clear */
182 clbss_l:str r2, [r0] /* clear loop... */
190 ldr pc, _start_armboot
197 *************************************************************************
199 * CPU_init_critical registers
201 * setup important registers
202 * setup memory timing
204 *************************************************************************
206 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
209 * flush v4 I/D caches
212 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
213 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
216 * disable MMU stuff and caches
218 mrc p15, 0, r0, c1, c0, 0
219 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
220 bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
221 orr r0, r0, #0x00000002 /* set bit 2 (A) Align */
222 orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
223 mcr p15, 0, r0, c1, c0, 0
226 * Go setup Memory and board specific bits prior to relocation.
228 mov ip, lr /* perserve link reg across call */
229 bl lowlevel_init /* go setup pll,mux,memory */
230 mov lr, ip /* restore link */
231 mov pc, lr /* back to my caller */
232 #endif /* CONFIG_SKIP_LOWLEVEL_INIT */
235 *************************************************************************
239 *************************************************************************
245 #define S_FRAME_SIZE 72
267 #define MODE_SVC 0x13
271 * use bad_save_user_regs for abort/prefetch/undef/swi ...
272 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
275 .macro bad_save_user_regs
276 @ carve out a frame on current user stack
277 sub sp, sp, #S_FRAME_SIZE
278 stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
280 ldr r2, _armboot_start
281 sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
282 sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
283 @ get values for "aborted" pc and cpsr (into parm regs)
285 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
288 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
289 mov r0, sp @ save current stack into r0 (param register)
292 .macro irq_save_user_regs
293 sub sp, sp, #S_FRAME_SIZE
294 stmia sp, {r0 - r12} @ Calling r0-r12
295 @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
297 stmdb r8, {sp, lr}^ @ Calling SP, LR
298 str lr, [r8, #0] @ Save calling PC
300 str r6, [r8, #4] @ Save CPSR
301 str r0, [r8, #8] @ Save OLD_R0
305 .macro irq_restore_user_regs
306 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
308 ldr lr, [sp, #S_PC] @ Get PC
309 add sp, sp, #S_FRAME_SIZE
310 subs pc, lr, #4 @ return & move spsr_svc into cpsr
314 ldr r13, _armboot_start @ setup our mode stack
315 sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
316 sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
318 str lr, [r13] @ save caller lr in position 0 of saved stack
319 mrs lr, spsr @ get the spsr
320 str lr, [r13, #4] @ save spsr in position 1 of saved stack
321 mov r13, #MODE_SVC @ prepare SVC-Mode
323 msr spsr, r13 @ switch modes, make sure moves will execute
324 mov lr, pc @ capture return pc
325 movs pc, lr @ jump to next instruction & switch modes.
328 .macro get_irq_stack @ setup IRQ stack
329 ldr sp, IRQ_STACK_START
332 .macro get_fiq_stack @ setup FIQ stack
333 ldr sp, FIQ_STACK_START
340 undefined_instruction:
343 bl do_undefined_instruction
349 bl do_software_interrupt
369 #ifdef CONFIG_USE_IRQ
376 irq_restore_user_regs
381 /* someone ought to write a more effiction fiq_save_user_regs */
384 irq_restore_user_regs