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 #ifdef CONFIG_PRELOADER
57 /* No exception handlers in preloader */
68 /* pad to 64 byte boundary */
77 ldr pc, _undefined_instruction
78 ldr pc, _software_interrupt
79 ldr pc, _prefetch_abort
85 _undefined_instruction:
86 .word undefined_instruction
88 .word software_interrupt
100 #endif /* CONFIG_PRELOADER */
101 .balignl 16,0xdeadbeef
105 *************************************************************************
107 * Startup Code (reset vector)
109 * do important init only if we don't start from memory!
110 * setup Memory and board specific bits prior to relocation.
111 * relocate armboot to ram
114 *************************************************************************
120 .globl _armboot_start
125 * These are defined in the board-specific linker script.
135 #ifdef CONFIG_USE_IRQ
136 /* IRQ stack memory (calculated at run-time) */
137 .globl IRQ_STACK_START
141 /* IRQ stack memory (calculated at run-time) */
142 .globl FIQ_STACK_START
149 * the actual reset code
154 * set the cpu to SVC32 mode
162 * we do sys-critical inits only at reboot,
163 * not when booting from ram!
165 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
169 #ifndef CONFIG_SKIP_RELOCATE_UBOOT
170 relocate: /* relocate U-Boot to RAM */
171 adr r0, _start /* r0 <- current position of code */
172 ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
173 cmp r0, r1 /* don't reloc during debug */
175 ldr r2, _armboot_start
177 sub r2, r3, r2 /* r2 <- size of armboot */
178 add r2, r0, r2 /* r2 <- source end address */
181 ldmia r0!, {r3-r10} /* copy from source address [r0] */
182 stmia r1!, {r3-r10} /* copy to target address [r1] */
183 cmp r0, r2 /* until source end addreee [r2] */
185 #endif /* CONFIG_SKIP_RELOCATE_UBOOT */
187 /* Set up the stack */
189 ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
190 sub sp, r0, #128 /* leave 32 words for abort-stack */
191 #ifndef CONFIG_PRELOADER
192 sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc area */
193 sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo */
194 #ifdef CONFIG_USE_IRQ
195 sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
197 #endif /* CONFIG_PRELOADER */
198 sub sp, r0, #12 /* leave 3 words for abort-stack */
199 bic sp, r0, #7 /* 8-byte align stack for ABI compliance */
202 ldr r0, _bss_start /* find start of bss segment */
203 ldr r1, _bss_end /* stop here */
204 mov r2, #0x00000000 /* clear */
206 #ifndef CONFIG_PRELOADER
207 clbss_l:str r2, [r0] /* clear loop... */
214 #endif /* CONFIG_PRELOADER */
216 ldr pc, _start_armboot
219 #ifdef CONFIG_NAND_SPL
223 #endif /* CONFIG_NAND_SPL */
227 *************************************************************************
229 * CPU_init_critical registers
231 * setup important registers
232 * setup memory timing
234 *************************************************************************
236 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
239 * flush v4 I/D caches
242 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
243 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
246 * disable MMU stuff and caches
248 mrc p15, 0, r0, c1, c0, 0
249 bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */
250 bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
251 orr r0, r0, #0x00000002 /* set bit 2 (A) Align */
252 orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
253 mcr p15, 0, r0, c1, c0, 0
256 * Go setup Memory and board specific bits prior to relocation.
258 mov ip, lr /* perserve link reg across call */
259 bl lowlevel_init /* go setup pll,mux,memory */
260 mov lr, ip /* restore link */
261 mov pc, lr /* back to my caller */
262 #endif /* CONFIG_SKIP_LOWLEVEL_INIT */
264 #ifndef CONFIG_PRELOADER
266 *************************************************************************
270 *************************************************************************
276 #define S_FRAME_SIZE 72
298 #define MODE_SVC 0x13
302 * use bad_save_user_regs for abort/prefetch/undef/swi ...
303 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
306 .macro bad_save_user_regs
307 @ carve out a frame on current user stack
308 sub sp, sp, #S_FRAME_SIZE
309 stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
311 ldr r2, _armboot_start
312 sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
313 sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack
314 @ get values for "aborted" pc and cpsr (into parm regs)
316 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
319 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
320 mov r0, sp @ save current stack into r0 (param register)
323 .macro irq_save_user_regs
324 sub sp, sp, #S_FRAME_SIZE
325 stmia sp, {r0 - r12} @ Calling r0-r12
326 @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
328 stmdb r8, {sp, lr}^ @ Calling SP, LR
329 str lr, [r8, #0] @ Save calling PC
331 str r6, [r8, #4] @ Save CPSR
332 str r0, [r8, #8] @ Save OLD_R0
336 .macro irq_restore_user_regs
337 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
339 ldr lr, [sp, #S_PC] @ Get PC
340 add sp, sp, #S_FRAME_SIZE
341 subs pc, lr, #4 @ return & move spsr_svc into cpsr
345 ldr r13, _armboot_start @ setup our mode stack
346 sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
347 sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
349 str lr, [r13] @ save caller lr in position 0 of saved stack
350 mrs lr, spsr @ get the spsr
351 str lr, [r13, #4] @ save spsr in position 1 of saved stack
352 mov r13, #MODE_SVC @ prepare SVC-Mode
354 msr spsr, r13 @ switch modes, make sure moves will execute
355 mov lr, pc @ capture return pc
356 movs pc, lr @ jump to next instruction & switch modes.
359 .macro get_irq_stack @ setup IRQ stack
360 ldr sp, IRQ_STACK_START
363 .macro get_fiq_stack @ setup FIQ stack
364 ldr sp, FIQ_STACK_START
366 #endif /* CONFIG_PRELOADER */
371 #ifdef CONFIG_PRELOADER
374 ldr sp, _TEXT_BASE /* switch to abort stack */
376 bl 1b /* hang and never return */
377 #else /* !CONFIG_PRELOADER */
379 undefined_instruction:
382 bl do_undefined_instruction
388 bl do_software_interrupt
408 #ifdef CONFIG_USE_IRQ
415 irq_restore_user_regs
420 /* someone ought to write a more effiction fiq_save_user_regs */
423 irq_restore_user_regs
440 #endif /* CONFIG_PRELOADER */