2 * armboot - Startup Code for ARM925 CPU-core
4 * Copyright (c) 2003 Texas Instruments
6 * ----- Adapted for OMAP1510 from ARM920 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 <gj@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,
37 #if defined(CONFIG_OMAP1510)
38 #include <./configs/omap1510.h>
42 *************************************************************************
44 * Jump vector table as in table 3.1 in [1]
46 *************************************************************************
52 ldr pc, _undefined_instruction
53 ldr pc, _software_interrupt
54 ldr pc, _prefetch_abort
60 _undefined_instruction: .word undefined_instruction
61 _software_interrupt: .word software_interrupt
62 _prefetch_abort: .word prefetch_abort
63 _data_abort: .word data_abort
64 _not_used: .word not_used
68 .balignl 16,0xdeadbeef
72 *************************************************************************
74 * Startup Code (reset vector)
76 * do important init only if we don't start from memory!
77 * setup Memory and board specific bits prior to relocation.
78 * relocate armboot to ram
81 *************************************************************************
85 * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
95 * Note: _armboot_end_data and _armboot_end are defined
96 * by the (board-dependent) linker script.
97 * _armboot_end_data is the first usable FLASH address after armboot
99 .globl _armboot_end_data
101 .word armboot_end_data
107 * _armboot_real_end is the first usable RAM address behind armboot
108 * and the various stacks
110 .globl _armboot_real_end
114 #ifdef CONFIG_USE_IRQ
115 /* IRQ stack memory (calculated at run-time) */
116 .globl IRQ_STACK_START
120 /* IRQ stack memory (calculated at run-time) */
121 .globl FIQ_STACK_START
128 * the actual reset code
133 * set the cpu to SVC32 mode
143 mov r1, #0x81 /* Set ARM925T configuration. */
144 mcr p15, 0, r1, c15, c1, 0 /* Write ARM925T configuration register. */
147 * turn off the watchdog, unlock/diable sequence
156 * mask all IRQs by setting all bits in the INTMR - default
159 ldr r0, =REG_IHL1_MIR
161 ldr r0, =REG_IHL2_MIR
165 * wait for dpll to lock
178 * relocate armboot to RAM
180 adr r0, _start /* r0 <- current position of code */
181 ldr r2, _armboot_start
183 sub r2, r3, r2 /* r2 <- size of armboot */
184 ldr r1, _TEXT_BASE /* r1 <- destination address */
185 add r2, r0, r2 /* r2 <- source end address */
188 * r0 = source address
189 * r1 = target address
190 * r2 = source end address
198 /* set up the stack */
200 add r0, r0, #CONFIG_STACKSIZE
201 sub sp, r0, #12 /* leave 3 words for abort-stack */
203 ldr pc, _start_armboot
205 _start_armboot: .word start_armboot
209 *************************************************************************
211 * CPU_init_critical registers
213 * setup important registers
214 * setup memory timing
216 *************************************************************************
222 * flush v4 I/D caches
225 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
226 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
229 * disable MMU stuff and caches
231 mrc p15, 0, r0, c1, c0, 0
232 bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS)
233 bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM)
234 orr r0, r0, #0x00000002 @ set bit 2 (A) Align
235 orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache
236 mcr p15, 0, r0, c1, c0, 0
239 * Go setup Memory and board specific bits prior to relocation.
241 mov ip, lr /* perserve link reg across call */
242 bl platformsetup /* go setup pll,mux,memory */
243 mov lr, ip /* restore link */
244 mov pc, lr /* back to my caller */
246 *************************************************************************
250 *************************************************************************
256 #define S_FRAME_SIZE 72
278 #define MODE_SVC 0x13
282 * use bad_save_user_regs for abort/prefetch/undef/swi ...
283 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
286 .macro bad_save_user_regs
287 sub sp, sp, #S_FRAME_SIZE @ carve out a frame on current user stack
288 stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
290 ldr r2, _armboot_end @ find top of stack
291 add r2, r2, #CONFIG_STACKSIZE @ find base of normal stack
292 sub r2, r2, #8 @ set base 2 words into abort stack
293 ldmia r2, {r2 - r3} @ get values for "aborted" pc and cpsr (into parm regs)
294 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
298 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
299 mov r0, sp @ save current stack into r0 (param register)
302 .macro irq_save_user_regs
303 sub sp, sp, #S_FRAME_SIZE
304 stmia sp, {r0 - r12} @ Calling r0-r12
305 add r8, sp, #S_PC @ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
306 stmdb r8, {sp, lr}^ @ Calling SP, LR
307 str lr, [r8, #0] @ Save calling PC
309 str r6, [r8, #4] @ Save CPSR
310 str r0, [r8, #8] @ Save OLD_R0
314 .macro irq_restore_user_regs
315 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
317 ldr lr, [sp, #S_PC] @ Get PC
318 add sp, sp, #S_FRAME_SIZE
319 subs pc, lr, #4 @ return & move spsr_svc into cpsr
323 ldr r13, _armboot_end @ get bottom of stack (into sp by by user stack pointer).
324 add r13, r13, #CONFIG_STACKSIZE @ head to reserved words at the top of the stack
325 sub r13, r13, #8 @ reserved a couple spots in abort stack
327 str lr, [r13] @ save caller lr in position 0 of saved stack
328 mrs lr, spsr @ get the spsr
329 str lr, [r13, #4] @ save spsr in position 1 of saved stack
331 mov r13, #MODE_SVC @ prepare SVC-Mode
333 msr spsr, r13 @ switch modes, make sure moves will execute
334 mov lr, pc @ capture return pc
335 movs pc, lr @ jump to next instruction & switch modes.
338 .macro get_irq_stack @ setup IRQ stack
339 ldr sp, IRQ_STACK_START
342 .macro get_fiq_stack @ setup FIQ stack
343 ldr sp, FIQ_STACK_START
350 undefined_instruction:
353 bl do_undefined_instruction
359 bl do_software_interrupt
379 #ifdef CONFIG_USE_IRQ
386 irq_restore_user_regs
391 /* someone ought to write a more effiction fiq_save_user_regs */
394 irq_restore_user_regs
415 ldr r1, rstctl1 /* get clkm1 reset ctl */
417 strh r3, [r1] /* clear it */
419 strh r3, [r1] /* force dsp+arm reset */