diff options
Diffstat (limited to 'u-boot/arch/arm/cpu/s3c44b0/start.S')
| -rw-r--r-- | u-boot/arch/arm/cpu/s3c44b0/start.S | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/u-boot/arch/arm/cpu/s3c44b0/start.S b/u-boot/arch/arm/cpu/s3c44b0/start.S new file mode 100644 index 0000000..9c9c3b3 --- /dev/null +++ b/u-boot/arch/arm/cpu/s3c44b0/start.S @@ -0,0 +1,349 @@ +/* + * Startup Code for S3C44B0 CPU-core + * + * (C) Copyright 2004 + * DAVE Srl + * + * http://www.dave-tech.it + * http://www.wawnet.biz + * mailto:info@wawnet.biz + * + * 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 <asm-offsets.h> +#include <config.h> +#include <version.h> + +/* + * Jump vector table + */ + + +.globl _start +_start: b reset + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + add pc, pc, #0x0c000000 + + .balignl 16,0xdeadbeef + + +/* + ************************************************************************* + * + * Startup Code (reset vector) + * + * do important init only if we don't start from memory! + * relocate u-boot to ram + * setup stack + * jump to second stage + * + ************************************************************************* + */ + +.globl _TEXT_BASE +_TEXT_BASE: + .word CONFIG_SYS_TEXT_BASE + +/* + * These are defined in the board-specific linker script. + * Subtracting _start from them lets the linker put their + * relative position in the executable instead of leaving + * them null. + */ +.globl _bss_start_ofs +_bss_start_ofs: + .word __bss_start - _start + +.globl _bss_end_ofs +_bss_end_ofs: + .word _end - _start + +#ifdef CONFIG_USE_IRQ +/* IRQ stack memory (calculated at run-time) */ +.globl IRQ_STACK_START +IRQ_STACK_START: + .word 0x0badc0de + +/* IRQ stack memory (calculated at run-time) */ +.globl FIQ_STACK_START +FIQ_STACK_START: + .word 0x0badc0de +#endif + +/* IRQ stack memory (calculated at run-time) + 8 bytes */ +.globl IRQ_STACK_START_IN +IRQ_STACK_START_IN: + .word 0x0badc0de + +/* + * 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 + + /* + * we do sys-critical inits only at reboot, + * not when booting from ram! + */ +#ifndef CONFIG_SKIP_LOWLEVEL_INIT + bl cpu_init_crit + /* + * before relocating, we have to setup RAM timing + * because memory timing is board-dependend, you will + * find a lowlevel_init.S in your board directory. + */ + bl lowlevel_init +#endif + +/* Set stackpointer in internal RAM to call board_init_f */ +call_board_init_f: + ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) + bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ + ldr r0,=0x00000000 + bl board_init_f + +/*------------------------------------------------------------------------------*/ + +/* + * void relocate_code (addr_sp, gd, addr_moni) + * + * This "function" does not return, instead it continues in RAM + * after relocating the monitor code. + * + */ + .globl relocate_code +relocate_code: + mov r4, r0 /* save addr_sp */ + mov r5, r1 /* save addr of gd */ + mov r6, r2 /* save addr of destination */ + + /* Set up the stack */ +stack_setup: + mov sp, r4 + + adr r0, _start + cmp r0, r6 + beq clear_bss /* skip relocation */ + mov r1, r6 /* r1 <- scratch for copy_loop */ + ldr r3, _bss_start_ofs + add r2, r0, r3 /* r2 <- source end address */ + +copy_loop: + ldmia r0!, {r9-r10} /* copy from source address [r0] */ + stmia r1!, {r9-r10} /* copy to target address [r1] */ + cmp r0, r2 /* until source end address [r2] */ + blo copy_loop + +#ifndef CONFIG_PRELOADER + /* + * fix .rel.dyn relocations + */ + ldr r0, _TEXT_BASE /* r0 <- Text base */ + sub r9, r6, r0 /* r9 <- relocation offset */ + ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */ + add r10, r10, r0 /* r10 <- sym table in FLASH */ + ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */ + add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ + ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */ + add r3, r3, r0 /* r3 <- rel dyn end in FLASH */ +fixloop: + ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */ + add r0, r0, r9 /* r0 <- location to fix up in RAM */ + ldr r1, [r2, #4] + and r7, r1, #0xff + cmp r7, #23 /* relative fixup? */ + beq fixrel + cmp r7, #2 /* absolute fixup? */ + beq fixabs + /* ignore unknown type of fixup */ + b fixnext +fixabs: + /* absolute fix: set location to (offset) symbol value */ + mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ + add r1, r10, r1 /* r1 <- address of symbol in table */ + ldr r1, [r1, #4] /* r1 <- symbol value */ + add r1, r1, r9 /* r1 <- relocated sym addr */ + b fixnext +fixrel: + /* relative fix: increase location by offset */ + ldr r1, [r0] + add r1, r1, r9 +fixnext: + str r1, [r0] + add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ + cmp r2, r3 + blo fixloop +#endif + +clear_bss: +#ifndef CONFIG_PRELOADER + ldr r0, _bss_start_ofs + ldr r1, _bss_end_ofs + mov r4, r6 /* reloc addr */ + add r0, r0, r4 + add r1, r1, r4 + mov r2, #0x00000000 /* clear */ + +clbss_l:str r2, [r0] /* clear loop... */ + add r0, r0, #4 + cmp r0, r1 + bne clbss_l + + bl coloured_LED_init + bl red_LED_on +#endif + +/* + * We are done. Do not return, instead branch to second part of board + * initialization, now running from RAM. + */ + ldr r0, _board_init_r_ofs + adr r1, _start + add lr, r0, r1 + add lr, lr, r9 + /* setup parameters for board_init_r */ + mov r0, r5 /* gd_t */ + mov r1, r6 /* dest_addr */ + /* jump to it ... */ + mov pc, lr + +_board_init_r_ofs: + .word board_init_r - _start + +_rel_dyn_start_ofs: + .word __rel_dyn_start - _start +_rel_dyn_end_ofs: + .word __rel_dyn_end - _start +_dynsym_start_ofs: + .word __dynsym_start - _start + +/* + ************************************************************************* + * + * CPU_init_critical registers + * + * setup important registers + * setup memory timing + * + ************************************************************************* + */ + +#define INTCON (0x01c00000+0x200000) +#define INTMSK (0x01c00000+0x20000c) +#define LOCKTIME (0x01c00000+0x18000c) +#define PLLCON (0x01c00000+0x180000) +#define CLKCON (0x01c00000+0x180004) +#define WTCON (0x01c00000+0x130000) +cpu_init_crit: + /* disable watch dog */ + ldr r0, =WTCON + ldr r1, =0x0 + str r1, [r0] + + /* + * mask all IRQs by clearing all bits in the INTMRs + */ + ldr r1,=INTMSK + ldr r0, =0x03fffeff + str r0, [r1] + + ldr r1, =INTCON + ldr r0, =0x05 + str r0, [r1] + + /* Set Clock Control Register */ + ldr r1, =LOCKTIME + ldrb r0, =800 + strb r0, [r1] + + ldr r1, =PLLCON + +#if CONFIG_S3C44B0_CLOCK_SPEED==66 + ldr r0, =0x34031 /* 66MHz (Quartz=11MHz) */ +#elif CONFIG_S3C44B0_CLOCK_SPEED==75 + ldr r0, =0x610c1 /*B2: Xtal=20mhz Fclk=75MHz */ +#else +# error CONFIG_S3C44B0_CLOCK_SPEED undefined +#endif + + str r0, [r1] + + ldr r1,=CLKCON + ldr r0, =0x7ff8 + str r0, [r1] + + mov pc, lr + + +/*************************************************/ +/* interrupt vectors */ +/*************************************************/ +real_vectors: + b reset + b undefined_instruction + b software_interrupt + b prefetch_abort + b data_abort + b not_used + b irq + b fiq + +/*************************************************/ + +undefined_instruction: + mov r6, #3 + b reset + +software_interrupt: + mov r6, #4 + b reset + +prefetch_abort: + mov r6, #5 + b reset + +data_abort: + mov r6, #6 + b reset + +not_used: + /* we *should* never reach this */ + mov r6, #7 + b reset + +irq: + mov r6, #8 + b reset + +fiq: + mov r6, #9 + b reset |