| Stefan Roese | c6bc1db | 2012-01-03 16:49:01 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * armboot - Startup Code for ARM926EJS CPU-core |
| 3 | * |
| 4 | * Copyright (c) 2003 Texas Instruments |
| 5 | * |
| 6 | * ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------ |
| 7 | * |
| 8 | * Copyright (c) 2001 Marius Gröger <mag@sysgo.de> |
| 9 | * Copyright (c) 2002 Alex Züpke <azu@sysgo.de> |
| 10 | * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de> |
| 11 | * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com> |
| 12 | * Copyright (c) 2003 Kshitij <kshitij@ti.com> |
| 13 | * |
| 14 | * See file CREDITS for list of people who contributed to this |
| 15 | * project. |
| 16 | * |
| 17 | * This program is free software; you can redistribute it and/or |
| 18 | * modify it under the terms of the GNU General Public License as |
| 19 | * published by the Free Software Foundation; either version 2 of |
| 20 | * the License, or (at your option) any later version. |
| 21 | * |
| 22 | * This program is distributed in the hope that it will be useful, |
| 23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 25 | * GNU General Public License for more details. |
| 26 | * |
| 27 | * You should have received a copy of the GNU General Public License |
| 28 | * along with this program; if not, write to the Free Software |
| 29 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 30 | * MA 02111-1307 USA |
| 31 | */ |
| 32 | |
| 33 | |
| 34 | #include <config.h> |
| 35 | |
| 36 | .globl _start |
| 37 | _start: |
| 38 | b reset |
| 39 | ldr pc, _undefined_instruction |
| 40 | ldr pc, _software_interrupt |
| 41 | ldr pc, _prefetch_abort |
| 42 | ldr pc, _data_abort |
| 43 | ldr pc, _not_used |
| 44 | ldr pc, _irq |
| 45 | ldr pc, _fiq |
| 46 | |
| 47 | _undefined_instruction: |
| 48 | _software_interrupt: |
| 49 | _prefetch_abort: |
| 50 | _data_abort: |
| 51 | _not_used: |
| 52 | _irq: |
| 53 | _fiq: |
| 54 | .word infinite_loop |
| 55 | |
| 56 | infinite_loop: |
| 57 | b infinite_loop |
| 58 | |
| 59 | /* |
| 60 | ************************************************************************* |
| 61 | * |
| 62 | * Startup Code (reset vector) |
| 63 | * |
| 64 | * Below are the critical initializations already taken place in BootROM. |
| 65 | * So, these are not taken care in Xloader |
| 66 | * 1. Relocation to RAM |
| 67 | * 2. Initializing stacks |
| 68 | * |
| 69 | ************************************************************************* |
| 70 | */ |
| 71 | |
| 72 | /* |
| 73 | * the actual reset code |
| 74 | */ |
| 75 | |
| 76 | reset: |
| 77 | /* |
| 78 | * Xloader has to return back to BootROM in a few cases. |
| 79 | * eg. Ethernet boot, UART boot, USB boot |
| 80 | * Saving registers for returning back |
| 81 | */ |
| 82 | stmdb sp!, {r0-r12,r14} |
| 83 | bl cpu_init_crit |
| 84 | /* |
| 85 | * Clearing bss area is not done in Xloader. |
| 86 | * BSS area lies in the DDR location which is not yet initialized |
| 87 | * bss is assumed to be uninitialized. |
| 88 | */ |
| 89 | bl spl_boot |
| 90 | ldmia sp!, {r0-r12,pc} |
| 91 | |
| 92 | /* |
| 93 | ************************************************************************* |
| 94 | * |
| 95 | * CPU_init_critical registers |
| 96 | * |
| 97 | * setup important registers |
| 98 | * setup memory timing |
| 99 | * |
| 100 | ************************************************************************* |
| 101 | */ |
| 102 | cpu_init_crit: |
| 103 | /* |
| 104 | * flush v4 I/D caches |
| 105 | */ |
| 106 | mov r0, #0 |
| 107 | mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ |
| 108 | mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ |
| 109 | |
| 110 | /* |
| 111 | * enable instruction cache |
| 112 | */ |
| 113 | mrc p15, 0, r0, c1, c0, 0 |
| 114 | orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */ |
| 115 | mcr p15, 0, r0, c1, c0, 0 |
| 116 | |
| 117 | /* |
| 118 | * Go setup Memory and board specific bits prior to relocation. |
| 119 | */ |
| 120 | stmdb sp!, {lr} |
| 121 | bl lowlevel_init /* go setup pll,mux,memory */ |
| 122 | ldmia sp!, {pc} |