1/* 2 * armboot - Startup Code for SA1100 CPU 3 * 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 * 9 * See file CREDITS for list of people who contributed to this 10 * project. 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License as 14 * published by the Free Software Foundation; either version 2 of 15 * the License, or (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 25 * MA 02111-1307 USA 26 */ 27 28#include <asm-offsets.h> 29#include <config.h> 30#include <version.h> 31 32/* 33 ************************************************************************* 34 * 35 * Jump vector table as in table 3.1 in [1] 36 * 37 ************************************************************************* 38 */ 39 40 41.globl _start 42_start: b reset 43 ldr pc, _undefined_instruction 44 ldr pc, _software_interrupt 45 ldr pc, _prefetch_abort 46 ldr pc, _data_abort 47 ldr pc, _not_used 48 ldr pc, _irq 49 ldr pc, _fiq 50 51_undefined_instruction: .word undefined_instruction 52_software_interrupt: .word software_interrupt 53_prefetch_abort: .word prefetch_abort 54_data_abort: .word data_abort 55_not_used: .word not_used 56_irq: .word irq 57_fiq: .word fiq 58 59 .balignl 16,0xdeadbeef 60 61 62/* 63 ************************************************************************* 64 * 65 * Startup Code (reset vector) 66 * 67 * do important init only if we don't start from memory! 68 * relocate armboot to ram 69 * setup stack 70 * jump to second stage 71 * 72 ************************************************************************* 73 */ 74 75.globl _TEXT_BASE 76_TEXT_BASE: 77#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE) 78 .word CONFIG_SPL_TEXT_BASE 79#else 80 .word CONFIG_SYS_TEXT_BASE 81#endif 82 83/* 84 * These are defined in the board-specific linker script. 85 * Subtracting _start from them lets the linker put their 86 * relative position in the executable instead of leaving 87 * them null. 88 */ 89.globl _bss_start_ofs 90_bss_start_ofs: 91 .word __bss_start - _start 92 93.globl _bss_end_ofs 94_bss_end_ofs: 95 .word __bss_end - _start 96 97.globl _end_ofs 98_end_ofs: 99 .word _end - _start 100 101#ifdef CONFIG_USE_IRQ 102/* IRQ stack memory (calculated at run-time) */ 103.globl IRQ_STACK_START 104IRQ_STACK_START: 105 .word 0x0badc0de 106 107/* IRQ stack memory (calculated at run-time) */ 108.globl FIQ_STACK_START 109FIQ_STACK_START: 110 .word 0x0badc0de 111#endif 112 113/* IRQ stack memory (calculated at run-time) + 8 bytes */ 114.globl IRQ_STACK_START_IN 115IRQ_STACK_START_IN: 116 .word 0x0badc0de 117 118/* 119 * the actual reset code 120 */ 121 122reset: 123 /* 124 * set the cpu to SVC32 mode 125 */ 126 mrs r0,cpsr 127 bic r0,r0,#0x1f 128 orr r0,r0,#0xd3 129 msr cpsr,r0 130 131 /* 132 * we do sys-critical inits only at reboot, 133 * not when booting from ram! 134 */ 135#ifndef CONFIG_SKIP_LOWLEVEL_INIT 136 bl cpu_init_crit 137#endif 138 139 bl _main 140 141/*------------------------------------------------------------------------------*/ 142 143/* 144 * void relocate_code (addr_sp, gd, addr_moni) 145 * 146 * This function relocates the monitor code. 147 */ 148 .globl relocate_code 149relocate_code: 150 mov r4, r0 /* save addr_sp */ 151 mov r5, r1 /* save addr of gd */ 152 mov r6, r2 /* save addr of destination */ 153 154 adr r0, _start 155 cmp r0, r6 156 moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */ 157 beq relocate_done /* skip relocation */ 158 mov r1, r6 /* r1 <- scratch for copy_loop */ 159 ldr r3, _bss_start_ofs 160 add r2, r0, r3 /* r2 <- source end address */ 161 162copy_loop: 163 ldmia r0!, {r9-r10} /* copy from source address [r0] */ 164 stmia r1!, {r9-r10} /* copy to target address [r1] */ 165 cmp r0, r2 /* until source end address [r2] */ 166 blo copy_loop 167 168#ifndef CONFIG_SPL_BUILD 169 /* 170 * fix .rel.dyn relocations 171 */ 172 ldr r0, _TEXT_BASE /* r0 <- Text base */ 173 sub r9, r6, r0 /* r9 <- relocation offset */ 174 ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */ 175 add r10, r10, r0 /* r10 <- sym table in FLASH */ 176 ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */ 177 add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ 178 ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */ 179 add r3, r3, r0 /* r3 <- rel dyn end in FLASH */ 180fixloop: 181 ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */ 182 add r0, r0, r9 /* r0 <- location to fix up in RAM */ 183 ldr r1, [r2, #4] 184 and r7, r1, #0xff 185 cmp r7, #23 /* relative fixup? */ 186 beq fixrel 187 cmp r7, #2 /* absolute fixup? */ 188 beq fixabs 189 /* ignore unknown type of fixup */ 190 b fixnext 191fixabs: 192 /* absolute fix: set location to (offset) symbol value */ 193 mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ 194 add r1, r10, r1 /* r1 <- address of symbol in table */ 195 ldr r1, [r1, #4] /* r1 <- symbol value */ 196 add r1, r1, r9 /* r1 <- relocated sym addr */ 197 b fixnext 198fixrel: 199 /* relative fix: increase location by offset */ 200 ldr r1, [r0] 201 add r1, r1, r9 202fixnext: 203 str r1, [r0] 204 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ 205 cmp r2, r3 206 blo fixloop 207#endif 208 209relocate_done: 210 211 mov pc, lr 212 213_rel_dyn_start_ofs: 214 .word __rel_dyn_start - _start 215_rel_dyn_end_ofs: 216 .word __rel_dyn_end - _start 217_dynsym_start_ofs: 218 .word __dynsym_start - _start 219 220 .globl c_runtime_cpu_setup 221c_runtime_cpu_setup: 222 223 mov pc, lr 224 225/* 226 ************************************************************************* 227 * 228 * CPU_init_critical registers 229 * 230 * setup important registers 231 * setup memory timing 232 * 233 ************************************************************************* 234 */ 235 236 237/* Interrupt-Controller base address */ 238IC_BASE: .word 0x90050000 239#define ICMR 0x04 240 241 242/* Reset-Controller */ 243RST_BASE: .word 0x90030000 244#define RSRR 0x00 245#define RCSR 0x04 246 247 248/* PWR */ 249PWR_BASE: .word 0x90020000 250#define PSPR 0x08 251#define PPCR 0x14 252cpuspeed: .word CONFIG_SYS_CPUSPEED 253 254 255cpu_init_crit: 256 /* 257 * mask all IRQs 258 */ 259 ldr r0, IC_BASE 260 mov r1, #0x00 261 str r1, [r0, #ICMR] 262 263 /* set clock speed */ 264 ldr r0, PWR_BASE 265 ldr r1, cpuspeed 266 str r1, [r0, #PPCR] 267 268 /* 269 * before relocating, we have to setup RAM timing 270 * because memory timing is board-dependend, you will 271 * find a lowlevel_init.S in your board directory. 272 */ 273 mov ip, lr 274 bl lowlevel_init 275 mov lr, ip 276 277 /* 278 * disable MMU stuff and enable I-cache 279 */ 280 mrc p15,0,r0,c1,c0 281 bic r0, r0, #0x00002000 @ clear bit 13 (X) 282 bic r0, r0, #0x0000000f @ clear bits 3-0 (WCAM) 283 orr r0, r0, #0x00001000 @ set bit 12 (I) Icache 284 orr r0, r0, #0x00000002 @ set bit 2 (A) Align 285 mcr p15,0,r0,c1,c0 286 287 /* 288 * flush v4 I/D caches 289 */ 290 mov r0, #0 291 mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ 292 mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ 293 294 mov pc, lr 295 296 297/* 298 ************************************************************************* 299 * 300 * Interrupt handling 301 * 302 ************************************************************************* 303 */ 304 305@ 306@ IRQ stack frame. 307@ 308#define S_FRAME_SIZE 72 309 310#define S_OLD_R0 68 311#define S_PSR 64 312#define S_PC 60 313#define S_LR 56 314#define S_SP 52 315 316#define S_IP 48 317#define S_FP 44 318#define S_R10 40 319#define S_R9 36 320#define S_R8 32 321#define S_R7 28 322#define S_R6 24 323#define S_R5 20 324#define S_R4 16 325#define S_R3 12 326#define S_R2 8 327#define S_R1 4 328#define S_R0 0 329 330#define MODE_SVC 0x13 331#define I_BIT 0x80 332 333/* 334 * use bad_save_user_regs for abort/prefetch/undef/swi ... 335 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling 336 */ 337 338 .macro bad_save_user_regs 339 sub sp, sp, #S_FRAME_SIZE 340 stmia sp, {r0 - r12} @ Calling r0-r12 341 add r8, sp, #S_PC 342 343 ldr r2, IRQ_STACK_START_IN 344 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0 345 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC 346 347 add r5, sp, #S_SP 348 mov r1, lr 349 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r 350 mov r0, sp 351 .endm 352 353 .macro irq_save_user_regs 354 sub sp, sp, #S_FRAME_SIZE 355 stmia sp, {r0 - r12} @ Calling r0-r12 356 add r8, sp, #S_PC 357 stmdb r8, {sp, lr}^ @ Calling SP, LR 358 str lr, [r8, #0] @ Save calling PC 359 mrs r6, spsr 360 str r6, [r8, #4] @ Save CPSR 361 str r0, [r8, #8] @ Save OLD_R0 362 mov r0, sp 363 .endm 364 365 .macro irq_restore_user_regs 366 ldmia sp, {r0 - lr}^ @ Calling r0 - lr 367 mov r0, r0 368 ldr lr, [sp, #S_PC] @ Get PC 369 add sp, sp, #S_FRAME_SIZE 370 subs pc, lr, #4 @ return & move spsr_svc into cpsr 371 .endm 372 373 .macro get_bad_stack 374 ldr r13, IRQ_STACK_START_IN @ setup our mode stack 375 376 str lr, [r13] @ save caller lr / spsr 377 mrs lr, spsr 378 str lr, [r13, #4] 379 380 mov r13, #MODE_SVC @ prepare SVC-Mode 381 msr spsr_c, r13 382 mov lr, pc 383 movs pc, lr 384 .endm 385 386 .macro get_irq_stack @ setup IRQ stack 387 ldr sp, IRQ_STACK_START 388 .endm 389 390 .macro get_fiq_stack @ setup FIQ stack 391 ldr sp, FIQ_STACK_START 392 .endm 393 394/* 395 * exception handlers 396 */ 397 .align 5 398undefined_instruction: 399 get_bad_stack 400 bad_save_user_regs 401 bl do_undefined_instruction 402 403 .align 5 404software_interrupt: 405 get_bad_stack 406 bad_save_user_regs 407 bl do_software_interrupt 408 409 .align 5 410prefetch_abort: 411 get_bad_stack 412 bad_save_user_regs 413 bl do_prefetch_abort 414 415 .align 5 416data_abort: 417 get_bad_stack 418 bad_save_user_regs 419 bl do_data_abort 420 421 .align 5 422not_used: 423 get_bad_stack 424 bad_save_user_regs 425 bl do_not_used 426 427#ifdef CONFIG_USE_IRQ 428 429 .align 5 430irq: 431 get_irq_stack 432 irq_save_user_regs 433 bl do_irq 434 irq_restore_user_regs 435 436 .align 5 437fiq: 438 get_fiq_stack 439 /* someone ought to write a more effiction fiq_save_user_regs */ 440 irq_save_user_regs 441 bl do_fiq 442 irq_restore_user_regs 443 444#else 445 446 .align 5 447irq: 448 get_bad_stack 449 bad_save_user_regs 450 bl do_irq 451 452 .align 5 453fiq: 454 get_bad_stack 455 bad_save_user_regs 456 bl do_fiq 457 458#endif 459 460 .align 5 461.globl reset_cpu 462reset_cpu: 463 ldr r0, RST_BASE 464 mov r1, #0x0 @ set bit 3-0 ... 465 str r1, [r0, #RCSR] @ ... to clear in RCSR 466 mov r1, #0x1 467 str r1, [r0, #RSRR] @ and perform reset 468 b reset_cpu @ silly, but repeat endlessly 469