2 * armboot - Startup Code for XScale
4 * Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
5 * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
6 * Copyright (C) 2000 Wolfgang Denk <wd@denx.de>
7 * Copyright (c) 2001 Alex Züpke <azu@sysgo.de>
8 * Copyright (c) 2002 Kyle Harris <kharris@nexus-tech.net>
10 * See file CREDITS for list of people who contributed to this
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of
16 * the License, or (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
36 ldr pc, _undefined_instruction
37 ldr pc, _software_interrupt
38 ldr pc, _prefetch_abort
44 _undefined_instruction: .word undefined_instruction
45 _software_interrupt: .word software_interrupt
46 _prefetch_abort: .word prefetch_abort
47 _data_abort: .word data_abort
48 _not_used: .word not_used
52 .balignl 16,0xdeadbeef
56 * Startup Code (reset vector)
58 * do important init only if we don't start from memory!
59 * - relocate armboot to ram
61 * - jump to second stage
65 * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
75 * Note: _armboot_end_data and _armboot_end are defined
76 * by the (board-dependent) linker script.
77 * _armboot_end_data is the first usable FLASH address after armboot
79 .globl _armboot_end_data
81 .word armboot_end_data
87 * _armboot_real_end is the first usable RAM address behind armboot
88 * and the various stacks
90 .globl _armboot_real_end
95 * We relocate uboot to this address (end of RAM - 128 KiB)
101 #ifdef CONFIG_USE_IRQ
102 /* IRQ stack memory (calculated at run-time) */
103 .globl IRQ_STACK_START
107 /* IRQ stack memory (calculated at run-time) */
108 .globl FIQ_STACK_START
114 /****************************************************************************/
116 /* the actual reset code */
118 /****************************************************************************/
121 mrs r0,cpsr /* set the cpu to SVC32 mode */
122 bic r0,r0,#0x1f /* (superviser mode, M=10011) */
126 bl cpu_init_crit /* we do sys-critical inits */
128 relocate: /* relocate U-Boot to RAM */
129 adr r0, _start /* r0 <- current position of code */
130 ldr r2, _armboot_start
132 sub r2, r3, r2 /* r2 <- size of armboot */
134 add r2, r0, r2 /* r2 <- source end address */
137 ldmia r0!, {r3-r10} /* copy from source address [r0] */
138 stmia r1!, {r3-r10} /* copy to target address [r1] */
139 cmp r0, r2 /* until source end addreee [r2] */
142 /* Set up the stack */
143 ldr r0, _uboot_reloc /* upper 128 KiB: relocated uboot */
144 sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
145 /* FIXME: bdinfo should be here */
146 sub sp, r0, #12 /* leave 3 words for abort-stack */
148 ldr pc, _start_armboot
150 _start_armboot: .word start_armboot
153 /****************************************************************************/
155 /* CPU_init_critical registers */
157 /* - setup important registers */
158 /* - setup memory timing */
160 /****************************************************************************/
162 /* Interrupt-Controller base address */
163 IC_BASE: .word 0x40d00000
166 /* Reset-Controller */
167 RST_BASE: .word 0x40f00030
171 /* Clock Manager Registers */
172 CC_BASE: .word 0x41300000
174 cpuspeed: .word CFG_CPUSPEED
191 /* set clock speed */
197 * before relocating, we have to setup RAM timing
198 * because memory timing is board-dependend, you will
199 * find a memsetup.S in your board directory.
205 /* Memory interfaces are working. Disable MMU and enable I-cache. */
207 ldr r0, =0x2001 /* enable access to all coproc. */
208 mcr p15, 0, r0, c15, c1, 0
211 mcr p15, 0, r0, c7, c10, 4 /* drain the write & fill buffers */
214 mcr p15, 0, r0, c7, c7, 0 /* flush Icache, Dcache and BTB */
217 mcr p15, 0, r0, c8, c7, 0 /* flush instuction and data TLBs */
220 /* Enable the Icache */
222 mrc p15, 0, r0, c1, c0, 0
224 mcr p15, 0, r0, c1, c0, 0
230 /****************************************************************************/
232 /* Interrupt handling */
234 /****************************************************************************/
236 /* IRQ stack frame */
238 #define S_FRAME_SIZE 72
260 #define MODE_SVC 0x13
262 /* use bad_save_user_regs for abort/prefetch/undef/swi ... */
264 .macro bad_save_user_regs
265 sub sp, sp, #S_FRAME_SIZE
266 stmia sp, {r0 - r12} /* Calling r0-r12 */
270 add r2, r2, #CONFIG_STACKSIZE
272 ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
273 add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
277 stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
282 /* use irq_save_user_regs / irq_restore_user_regs for */
283 /* IRQ/FIQ handling */
285 .macro irq_save_user_regs
286 sub sp, sp, #S_FRAME_SIZE
287 stmia sp, {r0 - r12} /* Calling r0-r12 */
289 stmdb r8, {sp, lr}^ /* Calling SP, LR */
290 str lr, [r8, #0] /* Save calling PC */
292 str r6, [r8, #4] /* Save CPSR */
293 str r0, [r8, #8] /* Save OLD_R0 */
297 .macro irq_restore_user_regs
298 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
300 ldr lr, [sp, #S_PC] @ Get PC
301 add sp, sp, #S_FRAME_SIZE
302 subs pc, lr, #4 @ return & move spsr_svc into cpsr
306 ldr r13, _armboot_end @ setup our mode stack
307 add r13, r13, #CONFIG_STACKSIZE @ resides at top of normal stack
310 str lr, [r13] @ save caller lr / spsr
314 mov r13, #MODE_SVC @ prepare SVC-Mode
320 .macro get_irq_stack @ setup IRQ stack
321 ldr sp, IRQ_STACK_START
324 .macro get_fiq_stack @ setup FIQ stack
325 ldr sp, FIQ_STACK_START
329 /****************************************************************************/
331 /* exception handlers */
333 /****************************************************************************/
336 undefined_instruction:
339 bl do_undefined_instruction
345 bl do_software_interrupt
365 #ifdef CONFIG_USE_IRQ
372 irq_restore_user_regs
377 irq_save_user_regs /* someone ought to write a more */
378 bl do_fiq /* effiction fiq_save_user_regs */
379 irq_restore_user_regs
398 * FIXME How do we reset??? Watchdog timeout??
405 mov r1, #0x0 @ set bit 3-0 ...
406 str r1, [r0, #RCSR] @ ... to clear in RCSR
408 str r1, [r0, #RCSR] @ and perform reset
410 b reset_cpu @ silly, but repeat endlessly