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Diffstat (limited to 'cpu/arm1136/start.S')
| -rw-r--r-- | cpu/arm1136/start.S | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/cpu/arm1136/start.S b/cpu/arm1136/start.S new file mode 100644 index 0000000..16108d0 --- /dev/null +++ b/cpu/arm1136/start.S @@ -0,0 +1,218 @@ +/* + * armboot - Startup Code for OMP2420/ARM1136 CPU-core + * + * Copyright (c) 2004 Texas Instruments + * + * 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> + +.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 + + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 + .word 0x12345678 /* now 16*4=64 */ + +.global _end_vect +_end_vect: + + .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 + + /* Copy vectors to mask ROM indirect addr */ + adr r0, _start /* r0 <- current position of code */ + add r0, r0, #4 /* skip reset vector */ + mov r2, #64 /* r2 <- size to copy */ + add r2, r0, r2 /* r2 <- source end address */ + mov r1, #0x40000000 /* build vect addr */ + mov r3, #0x00200000 + add r1, r1, r3 + mov r3, #0xf800 + add r1, r1, r3 +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] */ + bne next /* loop until equal */ + + bl cpy_clk_code /* put dpll adjust code behind vectors */ + + /* the mask ROM code should have PLL and others stable */ + bl cpu_init_crit + +relocate: /* relocate U-Boot 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 addreee [r2] */ + ble copy_loop + + /* Set up the stack */ +stack_setup: + ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */ + sub sp, r0, #128 /* leave 32 words for abort-stack */ + +clear_bss: + ldr r0, _bss_start /* find start of bss segment */ + 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 +#ifndef CONFIG_ICACHE_OFF + orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache +#endif + mcr p15, 0, r0, c1, c0, 0 + + /* + * Jump to board specific initialization... The Mask ROM will have already initialized + * basic memory. Go here to bump up clock rate and handle wake up conditions. + */ + adr r0, _start /* r0 <- current position of code */ + ldr r1, _TEXT_BASE /* test if we run from flash or RAM */ + cmp r0, r1 /* pass on info about skipping some init portions */ + moveq r0,#0x1 /* flag to skip prcm and sdrc setup */ + movne r0,#0x0 + +//mov r0, #1 /* this skip memory init */ + + mov ip, lr /* persevere 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 */ + |