diff options
Diffstat (limited to 'x-loader/cpu/arm926ejs/start.S')
| m--------- | x-loader | 0 | ||||
| -rw-r--r-- | x-loader/cpu/arm926ejs/start.S | 239 |
2 files changed, 239 insertions, 0 deletions
diff --git a/x-loader b/x-loader deleted file mode 160000 -Subproject 1c9276af4d6a5b7014a7630a1abeddf3b317756 diff --git a/x-loader/cpu/arm926ejs/start.S b/x-loader/cpu/arm926ejs/start.S new file mode 100644 index 0000000..2211dae --- /dev/null +++ b/x-loader/cpu/arm926ejs/start.S @@ -0,0 +1,239 @@ +/* + * armboot - Startup Code for ARM926EJS CPU-core + * + * Copyright (c) 2003 Texas Instruments + * + * ----- Adapted for OMAP1610 from ARM925t code ------ + * + * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> + * Copyright (c) 2002 Alex Züpke <azu@sysgo.de> + * Copyright (c) 2002 Gary Jennejohn <gj@denx.de> + * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com> + * Copyright (c) 2003 Kshitij <kshitij@ti.com> + * Copyright (c) 2004 Jian Zhang <jzhang@ti.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +#include <config.h> +#if defined(CONFIG_OMAP1610) +#include <./configs/omap1510.h> +#endif + +/* + ************************************************************************* + * + * Jump vector table as in table 3.1 in [1] + * + ************************************************************************* + */ + + +.globl _start +_start: + b reset + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + ldr pc, _hang + +_hang: + .word do_hang + + .balignl 16,0xdeadbeef + + +/* + ************************************************************************* + * + * Startup Code (reset vector) + * + * do important init only if we don't start from memory! + * setup Memory and board specific bits prior to relocation. + * relocate armboot to ram + * setup stack + * + ************************************************************************* + */ + +_TEXT_BASE: + .word TEXT_BASE + +.globl _armboot_start +_armboot_start: + .word _start + +/* + * These are defined in the board-specific linker script. + */ +.globl _bss_start +_bss_start: + .word __bss_start + +.globl _bss_end +_bss_end: + .word _end + + +/* + * the actual reset code + */ + +reset: + /* + * set the cpu to SVC32 mode + */ + mrs r0,cpsr + bic r0,r0,#0x1f + orr r0,r0,#0xd3 + msr cpsr,r0 + + /* + * turn off the watchdog, unlock/diable sequence + */ + mov r1, #0xF5 + ldr r0, =WDTIM_MODE + strh r1, [r0] + mov r1, #0xA0 + strh r1, [r0] + + + /* + * mask all IRQs by setting all bits in the INTMR - default + */ + + mov r1, #0xffffffff + ldr r0, =REG_IHL1_MIR + str r1, [r0] + ldr r0, =REG_IHL2_MIR + str r1, [r0] + + /* + * we do sys-critical inits at reboot, + */ + bl cpu_init_crit + + /* + * relocate exception vectors to SRAM where ROM code expects + */ +#ifdef CFG_BOOT_CS0 + + adr r0, _start /* r0 <- current position of code */ + add r0, r0, #4 /* skip reset vector */ + mov r2, #36 /* r2 <- size of data (8+1 words) */ + add r2, r0, r2 /* r2 <- source end address */ + mov r1, #0x20000000 +next: + ldmia r0!, {r3-r10} /* copy from source address [r0] */ + stmia r1!, {r3-r10} /* copy to target address [r1] */ + cmp r0, r2 /* until source end address [r2] */ + ble next + +#endif + +relocate: /* relocate X-Loader to RAM */ + adr r0, _start /* r0 <- current position of code */ + ldr r1, _TEXT_BASE /* test if we run from flash or RAM */ + cmp r0, r1 /* don't reloc during debug */ + /*beq stack_setup*/ + + ldr r2, _armboot_start + ldr r3, _bss_start + sub r2, r3, r2 /* r2 <- size of armboot */ + add r2, r0, r2 /* r2 <- source end address */ + +copy_loop: + ldmia r0!, {r3-r10} /* copy from source address [r0] */ + stmia r1!, {r3-r10} /* copy to target address [r1] */ + cmp r0, r2 /* until source end address [r2] */ + ble copy_loop + + /* Set up the stack */ +stack_setup: + ldr r0, _TEXT_BASE /* upper 128 KiB: relocated X-Loader */ + sub sp, r0, #128 /* leave 32 words for abort-stack */ + +clear_bss: + ldr r0, _bss_start /* find start of bss segment */ + add r0, r0, #4 /* start at first byte of bss */ + ldr r1, _bss_end /* stop here */ + mov r2, #0x00000000 /* clear */ + +clbss_l:str r2, [r0] /* clear loop... */ + add r0, r0, #4 + cmp r0, r1 + bne clbss_l + + ldr pc, _start_armboot + +_start_armboot: + .word start_armboot + + +/* + ************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + ************************************************************************* + */ + + +cpu_init_crit: + /* + * flush v4 I/D caches + */ + mov r0, #0 + mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ + mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ + + /* + * disable MMU stuff and caches + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #0x00002300 /* clear bits 13, 9:8 (--V- --RS) */ + bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */ + orr r0, r0, #0x00000002 /* set bit 2 (A) Align */ + orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */ + mcr p15, 0, r0, c1, c0, 0 + + /* + * Go setup Memory and board specific bits prior to relocation. + */ + mov ip, lr /* perserve link reg across call */ + bl platformsetup /* go setup pll,mux,memory */ + mov lr, ip /* restore link */ + mov pc, lr /* back to my caller */ + +/* + * exception handler + */ + .align 5 +do_hang: + ldr sp, _TEXT_BASE /* use 32 words abort stack */ + bl hang /* hang and never return */ + + |