1/* 2 * armboot - Startup Code for OMAP3530/ARM Cortex CPU-core 3 * 4 * Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com> 5 * 6 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> 7 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de> 8 * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de> 9 * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com> 10 * Copyright (c) 2003 Kshitij <kshitij@ti.com> 11 * Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com> 12 * 13 * See file CREDITS for list of people who contributed to this 14 * project. 15 * 16 * This program is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU General Public License as 18 * published by the Free Software Foundation; either version 2 of 19 * the License, or (at your option) any later version. 20 * 21 * This program is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 24 * GNU General Public License for more details. 25 * 26 * You should have received a copy of the GNU General Public License 27 * along with this program; if not, write to the Free Software 28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 29 * MA 02111-1307 USA 30 */ 31 32#include <asm-offsets.h> 33#include <config.h> 34#include <version.h> 35 36.globl _start 37_start: b reset 38 ldr pc, _undefined_instruction 39 ldr pc, _software_interrupt 40 ldr pc, _prefetch_abort 41 ldr pc, _data_abort 42 ldr pc, _not_used 43 ldr pc, _irq 44 ldr pc, _fiq 45 46_undefined_instruction: .word undefined_instruction 47_software_interrupt: .word software_interrupt 48_prefetch_abort: .word prefetch_abort 49_data_abort: .word data_abort 50_not_used: .word not_used 51_irq: .word irq 52_fiq: .word fiq 53_pad: .word 0x12345678 /* now 16*4=64 */ 54.global _end_vect 55_end_vect: 56 57 .balignl 16,0xdeadbeef 58/************************************************************************* 59 * 60 * Startup Code (reset vector) 61 * 62 * do important init only if we don't start from memory! 63 * setup Memory and board specific bits prior to relocation. 64 * relocate armboot to ram 65 * setup stack 66 * 67 *************************************************************************/ 68 69.globl _TEXT_BASE 70_TEXT_BASE: 71 .word CONFIG_SYS_TEXT_BASE 72 73#ifdef CONFIG_TEGRA2 74/* 75 * Tegra2 uses 2 separate CPUs - the AVP (ARM7TDMI) and the CPU (dual A9s). 76 * U-Boot runs on the AVP first, setting things up for the CPU (PLLs, 77 * muxes, clocks, clamps, etc.). Then the AVP halts, and expects the CPU 78 * to pick up its reset vector, which points here. 79 */ 80.globl _armboot_start 81_armboot_start: 82 .word _start 83#endif 84 85/* 86 * These are defined in the board-specific linker script. 87 */ 88.globl _bss_start_ofs 89_bss_start_ofs: 90 .word __bss_start - _start 91 92.globl _bss_end_ofs 93_bss_end_ofs: 94 .word __bss_end__ - _start 95 96.globl _end_ofs 97_end_ofs: 98 .word _end - _start 99 100#ifdef CONFIG_USE_IRQ 101/* IRQ stack memory (calculated at run-time) */ 102.globl IRQ_STACK_START 103IRQ_STACK_START: 104 .word 0x0badc0de 105 106/* IRQ stack memory (calculated at run-time) */ 107.globl FIQ_STACK_START 108FIQ_STACK_START: 109 .word 0x0badc0de 110#endif 111 112/* IRQ stack memory (calculated at run-time) + 8 bytes */ 113.globl IRQ_STACK_START_IN 114IRQ_STACK_START_IN: 115 .word 0x0badc0de 116 117/* 118 * the actual reset code 119 */ 120 121reset: 122 /* 123 * set the cpu to SVC32 mode 124 */ 125 mrs r0, cpsr 126 bic r0, r0, #0x1f 127 orr r0, r0, #0xd3 128 msr cpsr,r0 129 130#if defined(CONFIG_OMAP34XX) 131 /* Copy vectors to mask ROM indirect addr */ 132 adr r0, _start @ r0 <- current position of code 133 add r0, r0, #4 @ skip reset vector 134 mov r2, #64 @ r2 <- size to copy 135 add r2, r0, r2 @ r2 <- source end address 136 mov r1, #SRAM_OFFSET0 @ build vect addr 137 mov r3, #SRAM_OFFSET1 138 add r1, r1, r3 139 mov r3, #SRAM_OFFSET2 140 add r1, r1, r3 141next: 142 ldmia r0!, {r3 - r10} @ copy from source address [r0] 143 stmia r1!, {r3 - r10} @ copy to target address [r1] 144 cmp r0, r2 @ until source end address [r2] 145 bne next @ loop until equal */ 146#if !defined(CONFIG_SYS_NAND_BOOT) && !defined(CONFIG_SYS_ONENAND_BOOT) 147 /* No need to copy/exec the clock code - DPLL adjust already done 148 * in NAND/oneNAND Boot. 149 */ 150 bl cpy_clk_code @ put dpll adjust code behind vectors 151#endif /* NAND Boot */ 152#endif 153 /* the mask ROM code should have PLL and others stable */ 154#ifndef CONFIG_SKIP_LOWLEVEL_INIT 155 bl cpu_init_crit 156#endif 157 158/* Set stackpointer in internal RAM to call board_init_f */ 159call_board_init_f: 160 ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) 161 bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ 162 ldr r0,=0x00000000 163 bl board_init_f 164 165/*------------------------------------------------------------------------------*/ 166 167/* 168 * void relocate_code (addr_sp, gd, addr_moni) 169 * 170 * This "function" does not return, instead it continues in RAM 171 * after relocating the monitor code. 172 * 173 */ 174 .globl relocate_code 175relocate_code: 176 mov r4, r0 /* save addr_sp */ 177 mov r5, r1 /* save addr of gd */ 178 mov r6, r2 /* save addr of destination */ 179 180 /* Set up the stack */ 181stack_setup: 182 mov sp, r4 183 184 adr r0, _start 185#ifndef CONFIG_PRELOADER 186 cmp r0, r6 187 beq clear_bss /* skip relocation */ 188#endif 189 mov r1, r6 /* r1 <- scratch for copy_loop */ 190 ldr r3, _bss_start_ofs 191 add r2, r0, r3 /* r2 <- source end address */ 192 193copy_loop: 194 ldmia r0!, {r9-r10} /* copy from source address [r0] */ 195 stmia r1!, {r9-r10} /* copy to target address [r1] */ 196 cmp r0, r2 /* until source end address [r2] */ 197 blo copy_loop 198 199#ifndef CONFIG_PRELOADER 200 /* 201 * fix .rel.dyn relocations 202 */ 203 ldr r0, _TEXT_BASE /* r0 <- Text base */ 204 sub r9, r6, r0 /* r9 <- relocation offset */ 205 ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */ 206 add r10, r10, r0 /* r10 <- sym table in FLASH */ 207 ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */ 208 add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ 209 ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */ 210 add r3, r3, r0 /* r3 <- rel dyn end in FLASH */ 211fixloop: 212 ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */ 213 add r0, r0, r9 /* r0 <- location to fix up in RAM */ 214 ldr r1, [r2, #4] 215 and r7, r1, #0xff 216 cmp r7, #23 /* relative fixup? */ 217 beq fixrel 218 cmp r7, #2 /* absolute fixup? */ 219 beq fixabs 220 /* ignore unknown type of fixup */ 221 b fixnext 222fixabs: 223 /* absolute fix: set location to (offset) symbol value */ 224 mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ 225 add r1, r10, r1 /* r1 <- address of symbol in table */ 226 ldr r1, [r1, #4] /* r1 <- symbol value */ 227 add r1, r1, r9 /* r1 <- relocated sym addr */ 228 b fixnext 229fixrel: 230 /* relative fix: increase location by offset */ 231 ldr r1, [r0] 232 add r1, r1, r9 233fixnext: 234 str r1, [r0] 235 add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ 236 cmp r2, r3 237 blo fixloop 238 239clear_bss: 240 ldr r0, _bss_start_ofs 241 ldr r1, _bss_end_ofs 242 mov r4, r6 /* reloc addr */ 243 add r0, r0, r4 244 add r1, r1, r4 245 mov r2, #0x00000000 /* clear */ 246 247clbss_l:str r2, [r0] /* clear loop... */ 248 add r0, r0, #4 249 cmp r0, r1 250 bne clbss_l 251#endif /* #ifndef CONFIG_PRELOADER */ 252 253/* 254 * We are done. Do not return, instead branch to second part of board 255 * initialization, now running from RAM. 256 */ 257jump_2_ram: 258 ldr r0, _board_init_r_ofs 259 adr r1, _start 260 add lr, r0, r1 261 add lr, lr, r9 262 /* setup parameters for board_init_r */ 263 mov r0, r5 /* gd_t */ 264 mov r1, r6 /* dest_addr */ 265 /* jump to it ... */ 266 mov pc, lr 267 268_board_init_r_ofs: 269 .word board_init_r - _start 270 271_rel_dyn_start_ofs: 272 .word __rel_dyn_start - _start 273_rel_dyn_end_ofs: 274 .word __rel_dyn_end - _start 275_dynsym_start_ofs: 276 .word __dynsym_start - _start 277 278/************************************************************************* 279 * 280 * CPU_init_critical registers 281 * 282 * setup important registers 283 * setup memory timing 284 * 285 *************************************************************************/ 286cpu_init_crit: 287 /* 288 * Invalidate L1 I/D 289 */ 290 mov r0, #0 @ set up for MCR 291 mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs 292 mcr p15, 0, r0, c7, c5, 0 @ invalidate icache 293 294 /* 295 * disable MMU stuff and caches 296 */ 297 mrc p15, 0, r0, c1, c0, 0 298 bic r0, r0, #0x00002000 @ clear bits 13 (--V-) 299 bic r0, r0, #0x00000007 @ clear bits 2:0 (-CAM) 300 orr r0, r0, #0x00000002 @ set bit 1 (--A-) Align 301 orr r0, r0, #0x00000800 @ set bit 12 (Z---) BTB 302 mcr p15, 0, r0, c1, c0, 0 303 304 /* 305 * Jump to board specific initialization... 306 * The Mask ROM will have already initialized 307 * basic memory. Go here to bump up clock rate and handle 308 * wake up conditions. 309 */ 310 mov ip, lr @ persevere link reg across call 311 bl lowlevel_init @ go setup pll,mux,memory 312 mov lr, ip @ restore link 313 mov pc, lr @ back to my caller 314/* 315 ************************************************************************* 316 * 317 * Interrupt handling 318 * 319 ************************************************************************* 320 */ 321@ 322@ IRQ stack frame. 323@ 324#define S_FRAME_SIZE 72 325 326#define S_OLD_R0 68 327#define S_PSR 64 328#define S_PC 60 329#define S_LR 56 330#define S_SP 52 331 332#define S_IP 48 333#define S_FP 44 334#define S_R10 40 335#define S_R9 36 336#define S_R8 32 337#define S_R7 28 338#define S_R6 24 339#define S_R5 20 340#define S_R4 16 341#define S_R3 12 342#define S_R2 8 343#define S_R1 4 344#define S_R0 0 345 346#define MODE_SVC 0x13 347#define I_BIT 0x80 348 349/* 350 * use bad_save_user_regs for abort/prefetch/undef/swi ... 351 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling 352 */ 353 354 .macro bad_save_user_regs 355 sub sp, sp, #S_FRAME_SIZE @ carve out a frame on current 356 @ user stack 357 stmia sp, {r0 - r12} @ Save user registers (now in 358 @ svc mode) r0-r12 359 ldr r2, IRQ_STACK_START_IN @ set base 2 words into abort 360 @ stack 361 ldmia r2, {r2 - r3} @ get values for "aborted" pc 362 @ and cpsr (into parm regs) 363 add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack 364 365 add r5, sp, #S_SP 366 mov r1, lr 367 stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr 368 mov r0, sp @ save current stack into r0 369 @ (param register) 370 .endm 371 372 .macro irq_save_user_regs 373 sub sp, sp, #S_FRAME_SIZE 374 stmia sp, {r0 - r12} @ Calling r0-r12 375 add r8, sp, #S_PC @ !! R8 NEEDS to be saved !! 376 @ a reserved stack spot would 377 @ be good. 378 stmdb r8, {sp, lr}^ @ Calling SP, LR 379 str lr, [r8, #0] @ Save calling PC 380 mrs r6, spsr 381 str r6, [r8, #4] @ Save CPSR 382 str r0, [r8, #8] @ Save OLD_R0 383 mov r0, sp 384 .endm 385 386 .macro irq_restore_user_regs 387 ldmia sp, {r0 - lr}^ @ Calling r0 - lr 388 mov r0, r0 389 ldr lr, [sp, #S_PC] @ Get PC 390 add sp, sp, #S_FRAME_SIZE 391 subs pc, lr, #4 @ return & move spsr_svc into 392 @ cpsr 393 .endm 394 395 .macro get_bad_stack 396 ldr r13, IRQ_STACK_START_IN @ setup our mode stack (enter 397 @ in banked mode) 398 399 str lr, [r13] @ save caller lr in position 0 400 @ of saved stack 401 mrs lr, spsr @ get the spsr 402 str lr, [r13, #4] @ save spsr in position 1 of 403 @ saved stack 404 405 mov r13, #MODE_SVC @ prepare SVC-Mode 406 @ msr spsr_c, r13 407 msr spsr, r13 @ switch modes, make sure 408 @ moves will execute 409 mov lr, pc @ capture return pc 410 movs pc, lr @ jump to next instruction & 411 @ switch modes. 412 .endm 413 414 .macro get_bad_stack_swi 415 sub r13, r13, #4 @ space on current stack for 416 @ scratch reg. 417 str r0, [r13] @ save R0's value. 418 ldr r0, IRQ_STACK_START_IN @ get data regions start 419 @ spots for abort stack 420 str lr, [r0] @ save caller lr in position 0 421 @ of saved stack 422 mrs r0, spsr @ get the spsr 423 str lr, [r0, #4] @ save spsr in position 1 of 424 @ saved stack 425 ldr r0, [r13] @ restore r0 426 add r13, r13, #4 @ pop stack entry 427 .endm 428 429 .macro get_irq_stack @ setup IRQ stack 430 ldr sp, IRQ_STACK_START 431 .endm 432 433 .macro get_fiq_stack @ setup FIQ stack 434 ldr sp, FIQ_STACK_START 435 .endm 436 437/* 438 * exception handlers 439 */ 440 .align 5 441undefined_instruction: 442 get_bad_stack 443 bad_save_user_regs 444 bl do_undefined_instruction 445 446 .align 5 447software_interrupt: 448 get_bad_stack_swi 449 bad_save_user_regs 450 bl do_software_interrupt 451 452 .align 5 453prefetch_abort: 454 get_bad_stack 455 bad_save_user_regs 456 bl do_prefetch_abort 457 458 .align 5 459data_abort: 460 get_bad_stack 461 bad_save_user_regs 462 bl do_data_abort 463 464 .align 5 465not_used: 466 get_bad_stack 467 bad_save_user_regs 468 bl do_not_used 469 470#ifdef CONFIG_USE_IRQ 471 472 .align 5 473irq: 474 get_irq_stack 475 irq_save_user_regs 476 bl do_irq 477 irq_restore_user_regs 478 479 .align 5 480fiq: 481 get_fiq_stack 482 /* someone ought to write a more effective fiq_save_user_regs */ 483 irq_save_user_regs 484 bl do_fiq 485 irq_restore_user_regs 486 487#else 488 489 .align 5 490irq: 491 get_bad_stack 492 bad_save_user_regs 493 bl do_irq 494 495 .align 5 496fiq: 497 get_bad_stack 498 bad_save_user_regs 499 bl do_fiq 500 501#endif 502