学习S3C6410最好的办法是从裸机程序开始，下面的程序是一个实现简单功能的S3C6410入门裸机程序。
s3c6410裸机程序：从uboot程序中提取的代码，包括初始化时钟、256M DDR、初始化串口等。
编译工具：arm-linux-gcc。
mini6410.h
/*
* gbing163@163.com
* 2012-7-9
*/
#ifndef __CONFIG_H
#define __CONFIG_H
/*
* High Level Configuration Options
* (easy to change)
*/
#define CONFIG_S3C6410 1 /* in a SAMSUNG S3C6410 SoC */
#define CONFIG_S3C64XX 1 /* in a SAMSUNG S3C64XX Family */
#define CONFIG_MINI6410 1 /* on a FriendlyARM MINI6410 Board */
#define MEMORY_BASE_ADDRESS 0x50000000
/* input clock of PLL */
#define CONFIG_SYS_CLK_FREQ 12000000 /* the SMDK6400 has 12MHz input clock */
//#define CONFIG_ENABLE_MMU disable by gong
#ifdef CONFIG_ENABLE_MMU
#define virt_to_phys(x) virt_to_phy_smdk6410(x)
#else
#define virt_to_phys(x) (x)
#endif
//#define CONFIG_MEMORY_UPPER_CODE
#undef CONFIG_USE_IRQ /* we don't need IRQ/FIQ stuff */
//#define CONFIG_INCLUDE_TEST
//#define CONFIG_ZIMAGE_BOOT
//#define CONFIG_IMAGE_BOOT
#define BOARD_LATE_INIT
#define CONFIG_SETUP_MEMORY_TAGS
//#define CONFIG_CMDLINE_TAG
//#define CONFIG_INITRD_TAG
/*
* Architecture magic and machine type
*/
#define MACH_TYPE 2520
#define UBOOT_MAGIC (0x43090000 | MACH_TYPE)
/* Power Management is enabled */
//#define CONFIG_PM
#define CONFIG_DISPLAY_CPUINFO
#define CONFIG_DISPLAY_BOARDINFO
#undef CONFIG_SKIP_RELOCATE_UBOOT
#undef CONFIG_USE_NOR_BOOT
/*
* Size of malloc() pool
*/
#define CFG_MALLOC_LEN (1*1024*1024)
//#define CFG_GBL_DATA_SIZE 128 /* size in bytes reserved for initial data */
#define CFG_STACK_SIZE 512*1024
/*
* select serial console configuration
*/
#define CONFIG_SERIAL1 1 /* we use SERIAL 1 on SMDK6400 */
/* the PWM TImer 4 uses a counter of 15625 for 10 ms, so we need */
/* it to wrap 100 times (total 1562500) to get 1 sec. */
#define CFG_HZ 2062500 // at PCLK 66MHz
/* valid baudrates */
#define CFG_BAUDRATE_TABLE { 9600, 19200, 38400, 57600, 115200 }
/*-----------------------------------------------------------------------
* Stack sizes
*
* The stack sizes are set up in start.S using the settings below
*/
#define CONFIG_STACKSIZE 0x40000 /* regular stack 256KB */
#ifdef CONFIG_USE_IRQ
#define CONFIG_STACKSIZE_IRQ (2*1024) /* IRQ stack */
#define CONFIG_STACKSIZE_FIQ (2*1024) /* FIQ stack */
#endif
#define CONFIG_STACKSIZE_SVC (2*1024)
//#define CONFIG_CLK_800_133_66
//#define CONFIG_CLK_666_133_66
#define CONFIG_CLK_532_133_66
//#define CONFIG_CLK_400_133_66
//#define CONFIG_CLK_400_100_50
//#define CONFIG_CLK_OTHERS
#define CONFIG_CLKSRC_CLKUART
#define set_pll(mdiv, pdiv, sdiv) (1<<31 | mdiv<<16 | pdiv<<8 | sdiv)
#if defined(CONFIG_CLK_666_133_66) /* FIN 12MHz, Fout 666MHz */
#define APLL_MDIV 333
#define APLL_PDIV 3
#define APLL_SDIV 1
#undef CONFIG_SYNC_MODE /* ASYNC MODE */
#elif defined(CONFIG_CLK_532_133_66) /* FIN 12MHz, Fout 532MHz */
#define APLL_MDIV 266
#define APLL_PDIV 3
#define APLL_SDIV 1
#define CONFIG_SYNC_MODE
#elif defined(CONFIG_CLK_400_133_66) || defined(CONFIG_CLK_800_133_66) /* FIN 12MHz, Fout 800MHz */
#define APLL_MDIV 400
#define APLL_PDIV 3
#define APLL_SDIV 1
#define CONFIG_SYNC_MODE
#elif defined(CONFIG_CLK_400_100_50) /* FIN 12MHz, Fout 400MHz */
#define APLL_MDIV 400
#define APLL_PDIV 3
#define APLL_SDIV 2
#define CONFIG_SYNC_MODE
#elif defined(CONFIG_CLK_OTHERS)
/*If you have to use another value, please define pll value here*/
/* FIN 12MHz, Fout 532MHz */
#define APLL_MDIV 266
#define APLL_PDIV 3
#define APLL_SDIV 1
#define CONFIG_SYNC_MODE
#else
#error "Not Support Fequency or Mode!! you have to setup right configuration."
#endif
#define CONFIG_UART_66 /* default clock value of CLK_UART */
#define APLL_VAL set_pll(APLL_MDIV, APLL_PDIV, APLL_SDIV)
/* prevent overflow */
#define Startup_APLL (CONFIG_SYS_CLK_FREQ/(APLL_PDIV<<APLL_SDIV)*APLL_MDIV)
/* fixed MPLL 533MHz */
#define MPLL_MDIV 266
#define MPLL_PDIV 3
#define MPLL_SDIV 1
#define MPLL_VAL set_pll(MPLL_MDIV, MPLL_PDIV, MPLL_SDIV)
/* prevent overflow */
#define Startup_MPLL ((CONFIG_SYS_CLK_FREQ)/(MPLL_PDIV<<MPLL_SDIV)*MPLL_MDIV)
#if defined(CONFIG_CLK_800_133_66)
#define Startup_APLLdiv 0
#define Startup_HCLKx2div 2
#elif defined(CONFIG_CLK_400_133_66)
#define Startup_APLLdiv 1
#define Startup_HCLKx2div 2
#else
#define Startup_APLLdiv 0
#define Startup_HCLKx2div 1
#endif
#define Startup_PCLKdiv 3
#define Startup_HCLKdiv 1
#define Startup_MPLLdiv 1
#define CLK_DIV_VAL ((Startup_PCLKdiv<<12)|(Startup_HCLKx2div<<9)|(Startup_HCLKdiv<<8)|(Startup_MPLLdiv<<4)|Startup_APLLdiv)
#if defined(CONFIG_SYNC_MODE)
#define Startup_HCLK (Startup_APLL/(Startup_HCLKx2div+1)/(Startup_HCLKdiv+1))
#else
#define Startup_HCLK (Startup_MPLL/(Startup_HCLKx2div+1)/(Startup_HCLKdiv+1))
#endif
#if defined(FRIENDLYARM_BOOT_RAM256)
#define DMC1_MEM_CFG ((1<<30) | (2<<15) | (3<<3) | (2<<0))
#define DMC1_CHIP0_CFG 0x150F0
#define PHYS_SDRAM_1_SIZE 0x10000000 /* 256 MB */
#elif defined(FRIENDLYARM_BOOT_RAM128)
#define DMC1_MEM_CFG ((1<<30) | (2<<15) | (2<<3)| (2<<0))
#define DMC1_CHIP0_CFG 0x150F8
#define PHYS_SDRAM_1_SIZE 0x8000000 /* 128 MB */
#else
#error RAM size must be defined
#endif
/*-----------------------------------------------------------------------
* Physical Memory Map
*/
#define DMC1_MEM_CFG2 0xB41
#define DMC_DDR_32_CFG 0x0 /* 32bit, DDR */
/* Memory Parameters */
/* DDR Parameters */
#define DDR_tREFRESH 7800 /* ns */
#define DDR_tRAS 45 /* ns (min: 45ns)*/
#define DDR_tRC 68 /* ns (min: 67.5ns)*/
#define DDR_tRCD 23 /* ns (min: 22.5ns)*/
#define DDR_tRFC 80 /* ns (min: 80ns)*/
#define DDR_tRP 23 /* ns (min: 22.5ns)*/
#define DDR_tRRD 15 /* ns (min: 15ns)*/
#define DDR_tWR 15 /* ns (min: 15ns)*/
#define DDR_tXSR 120 /* ns (min: 120ns)*/
#define DDR_CASL 3 /* CAS Latency 3 */
/*
* mDDR memory configuration
*/
#define DMC_DDR_BA_EMRS 2
#define DMC_DDR_MEM_CASLAT 3
#define DMC_DDR_CAS_LATENCY (DDR_CASL<<1) //6 Set Cas Latency to 3
#define DMC_DDR_t_DQSS 1 // Min 0.75 ~ 1.25
#define DMC_DDR_t_MRD 2 //Min 2 tck
#define DMC_DDR_t_RAS (((Startup_HCLK / 1000 * DDR_tRAS) - 1) / 1000000 + 1) //7, Min 45ns
#define DMC_DDR_t_RC (((Startup_HCLK / 1000 * DDR_tRC) - 1) / 1000000 + 1) //10, Min 67.5ns
#define DMC_DDR_t_RCD (((Startup_HCLK / 1000 * DDR_tRCD) - 1) / 1000000 + 1) //4,5(TRM), Min 22.5ns
#define DMC_DDR_schedule_RCD ((DMC_DDR_t_RCD - 3) << 3)
#define DMC_DDR_t_RFC (((Startup_HCLK / 1000 * DDR_tRFC) - 1) / 1000000 + 1) //11,18(TRM) Min 80ns
#define DMC_DDR_schedule_RFC ((DMC_DDR_t_RFC - 3) << 5)
#define DMC_DDR_t_RP (((Startup_HCLK / 1000 * DDR_tRP) - 1) / 1000000 + 1) //4, 5(TRM) Min 22.5ns
#define DMC_DDR_schedule_RP ((DMC_DDR_t_RP - 3) << 3)
#define DMC_DDR_t_RRD (((Startup_HCLK / 1000 * DDR_tRRD) - 1) / 1000000 + 1) //3, Min 15ns
#define DMC_DDR_t_WR (((Startup_HCLK / 1000 * DDR_tWR) - 1) / 1000000 + 1) //Min 15ns
#define DMC_DDR_t_WTR 2
#define DMC_DDR_t_XP 2 //1tck + tIS(1.5ns)
#define DMC_DDR_t_XSR (((Startup_HCLK / 1000 * DDR_tXSR) - 1) / 1000000 + 1) //17, Min 120ns
#define DMC_DDR_t_ESR DMC_DDR_t_XSR
#define DMC_DDR_REFRESH_PRD (((Startup_HCLK / 1000 * DDR_tREFRESH) - 1) / 1000000) // TRM 2656
#define DMC_DDR_USER_CONFIG 1 // 2b01 : mDDR
#define CONFIG_NR_DRAM_BANKS 1 /* we have 2 bank of DRAM */
#define PHYS_SDRAM_1 MEMORY_BASE_ADDRESS /* SDRAM Bank #1 */
//#define PHYS_SDRAM_1_SIZE 0x08000000 /* 128 MB */
/* total memory required by uboot */
#define CFG_UBOOT_SIZE (1*1024*1024)
/* base address */
#define CFG_PROG_BASE MEMORY_BASE_ADDRESS
#define CFG_PHY_UBOOT_BASE MEMORY_BASE_ADDRESS
#endif /* __CONFIG_H */
start.S
#include <config.h>
//#include <version.h>
//#include <regs.h>
#ifndef CONFIG_ENABLE_MMU
#ifndef CFG_PHY_UBOOT_BASE
#define CFG_PHY_UBOOT_BASE CFG_UBOOT_BASE
#endif
#endif
/*
*************************************************************************
*
* Jump vector table as in table 3.1 in [1]
*
*************************************************************************
*/
.globl _start
_start: b reset
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
ldr pc, _data_abort
ldr pc, _not_used
ldr pc, _irq
ldr pc, _fiq
_undefined_instruction:
.word undefined_instruction
_software_interrupt:
.word software_interrupt
_prefetch_abort:
.word prefetch_abort
_data_abort:
.word data_abort
_not_used:
.word not_used
_irq:
.word irq
_fiq:
.word fiq
_pad:
.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
/*
* Below variable is very important because we use MMU in U-Boot.
* Without it, we cannot run code correctly before MMU is ON.
* by scsuh.
*/
_TEXT_PHY_BASE:
.word CFG_PHY_UBOOT_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
#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
/*
* 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
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
/*
* we do sys-critical inits only at reboot,
* not when booting from ram!
*/
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
/* Peri port setup */
ldr r0, =0x70000000
orr r0, r0, #0x13
mcr p15,0,r0,c15,c2,4 @ 256M(0x70000000-0x7fffffff)
/*
* Go setup Memory and board specific bits prior to relocation.
*/
bl lowlevel_init /* go setup pll,mux,memory */
#if 0
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0xC00
str r1, [r0, #GPPDAT_OFFSET]
ldr r1, [r0, #GPFPUD_OFFSET]
bic r1, r1, #0xc0000000
orr r1, r1, #0x80000000
str r1, [r0, #GPFPUD_OFFSET]
ldr r1, [r0, #GPFDAT_OFFSET]
orr r1, r1, #0x8000
str r1, [r0, #GPFDAT_OFFSET]
ldr r1, [r0, #GPFCON_OFFSET]
bic r1, r1, #0xc0000000
orr r1, r1, #0x40000000
str r1, [r0, #GPFCON_OFFSET]
#endif
skip_hw_init:
/* Set up the stack */
stack_setup:
ldr r0, _bss_start /* upper 128 KiB: relocated uboot */
add r0, r0, #CFG_MALLOC_LEN /* malloc area */
add r0, r0, #CONFIG_STACKSIZE_SVC
mov sp, r0
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
ble clbss_l
ldr pc, _start_armboot
_start_armboot:
.word start_armboot
/*
*************************************************************************
*
* Interrupt handling
*
*************************************************************************
*/
@
@ IRQ stack frame.
@
#define S_FRAME_SIZE 72
#define S_OLD_R0 68
#define S_PSR 64
#define S_PC 60
#define S_LR 56
#define S_SP 52
#define S_IP 48
#define S_FP 44
#define S_R10 40
#define S_R9 36
#define S_R8 32
#define S_R7 28
#define S_R6 24
#define S_R5 20
#define S_R4 16
#define S_R3 12
#define S_R2 8
#define S_R1 4
#define S_R0 0
#define MODE_SVC 0x13
#define I_BIT 0x80
/*
* exception handlers
*/
.align 5
undefined_instruction:
b undefined_instruction
.align 5
software_interrupt:
b software_interrupt
.align 5
prefetch_abort:
b prefetch_abort
.align 5
data_abort:
b data_abort
.align 5
not_used:
b not_used
#ifdef CONFIG_USE_IRQ
.align 5
irq:
b irq
.align 5
fiq:
b fiq
#else
.align 5
irq:
b irq
.align 5
fiq:
b fiq
#endif
cpu_init.S
#include <config.h> #include <s3c6410.h> .globl mem_ctrl_asm_init mem_ctrl_asm_init: ldr r0, =ELFIN_MEM_SYS_CFG @Memory sussystem address 0x7e00f120 mov r1, #0xd @ Xm0CSn2 = NFCON CS0, Xm0CSn3 = NFCON CS1 str r1, [r0] ldr r0, =ELFIN_DMC1_BASE @DMC1 base address 0x7e001000 ldr r1, =0x04 str r1, [r0, #INDEX_DMC_MEMC_CMD] ldr r1, =DMC_DDR_REFRESH_PRD str r1, [r0, #INDEX_DMC_REFRESH_PRD] ldr r1, =DMC_DDR_CAS_LATENCY str r1, [r0, #INDEX_DMC_CAS_LATENCY] ldr r1, =DMC_DDR_t_DQSS str r1, [r0, #INDEX_DMC_T_DQSS] ldr r1, =DMC_DDR_t_MRD str r1, [r0, #INDEX_DMC_T_MRD] ldr r1, =DMC_DDR_t_RAS str r1, [r0, #INDEX_DMC_T_RAS] ldr r1, =DMC_DDR_t_RC str r1, [r0, #INDEX_DMC_T_RC] ldr r1, =DMC_DDR_t_RCD ldr r2, =DMC_DDR_schedule_RCD orr r1, r1, r2 str r1, [r0, #INDEX_DMC_T_RCD] ldr r1, =DMC_DDR_t_RFC ldr r2, =DMC_DDR_schedule_RFC orr r1, r1, r2 str r1, [r0, #INDEX_DMC_T_RFC] ldr r1, =DMC_DDR_t_RP ldr r2, =DMC_DDR_schedule_RP orr r1, r1, r2 str r1, [r0, #INDEX_DMC_T_RP] ldr r1, =DMC_DDR_t_RRD str r1, [r0, #INDEX_DMC_T_RRD] ldr r1, =DMC_DDR_t_WR str r1, [r0, #INDEX_DMC_T_WR] ldr r1, =DMC_DDR_t_WTR str r1, [r0, #INDEX_DMC_T_WTR] ldr r1, =DMC_DDR_t_XP str r1, [r0, #INDEX_DMC_T_XP] ldr r1, =DMC_DDR_t_XSR str r1, [r0, #INDEX_DMC_T_XSR] ldr r1, =DMC_DDR_t_ESR str r1, [r0, #INDEX_DMC_T_ESR] ldr r1, =DMC1_MEM_CFG str r1, [r0, #INDEX_DMC_MEMORY_CFG] ldr r1, =DMC1_MEM_CFG2 str r1, [r0, #INDEX_DMC_MEMORY_CFG2] ldr r1, =DMC1_CHIP0_CFG str r1, [r0, #INDEX_DMC_CHIP_0_CFG] ldr r1, =DMC_DDR_32_CFG str r1, [r0, #INDEX_DMC_USER_CONFIG] @DMC0 DDR Chip 0 configuration direct command reg ldr r1, =DMC_NOP0 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Precharge All ldr r1, =DMC_PA0 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Auto Refresh 2 time ldr r1, =DMC_AR0 str r1, [r0, #INDEX_DMC_DIRECT_CMD] str r1, [r0, #INDEX_DMC_DIRECT_CMD] @MRS ldr r1, =DMC_mDDR_EMR0 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Mode Reg ldr r1, =DMC_mDDR_MR0 str r1, [r0, #INDEX_DMC_DIRECT_CMD] #ifdef CONFIG_SMDK6410_X5A ldr r1, =DMC1_CHIP1_CFG str r1, [r0, #INDEX_DMC_CHIP_1_CFG] @DMC0 DDR Chip 0 configuration direct command reg ldr r1, =DMC_NOP1 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Precharge All ldr r1, =DMC_PA1 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Auto Refresh 2 time ldr r1, =DMC_AR1 str r1, [r0, #INDEX_DMC_DIRECT_CMD] str r1, [r0, #INDEX_DMC_DIRECT_CMD] @MRS ldr r1, =DMC_mDDR_EMR1 str r1, [r0, #INDEX_DMC_DIRECT_CMD] @Mode Reg ldr r1, =DMC_mDDR_MR1 str r1, [r0, #INDEX_DMC_DIRECT_CMD] #endif @Enable DMC1 mov r1, #0x0 str r1, [r0, #INDEX_DMC_MEMC_CMD] check_dmc1_ready: ldr r1, [r0, #INDEX_DMC_MEMC_STATUS] mov r2, #0x3 and r1, r1, r2 cmp r1, #0x1 bne check_dmc1_ready nop mov pc, lr /* Below code is for ARM926EJS and ARM1026EJS */ .globl cleanDCache cleanDCache: mrc p15, 0, pc, c7, c10, 3 /* test/clean D-Cache */ bne cleanDCache mov pc, lr .globl cleanFlushDCache cleanFlushDCache: mrc p15, 0, pc, c7, c14, 3 /* test/cleanflush D-Cache */ bne cleanFlushDCache mov pc, lr .globl cleanFlushCache cleanFlushCache: mrc p15, 0, pc, c7, c14, 3 /* test/cleanflush D-Cache */ bne cleanFlushCache mcr p15, 0, r0, c7, c5, 0 /* flush I-Cache */ mov pc, lr .ltorg
lowlevel_init.S
/*
* Memory Setup stuff - taken from blob memsetup.S
*
* Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and
* Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
*
* Modified for the Samsung SMDK2410 by
* (C) Copyright 2002
* David Mueller, ELSOFT AG, <d.mueller@elsoft.ch>
*
* 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>
#include <s3c6410.h>
_TEXT_BASE:
.word TEXT_BASE
.globl lowlevel_init
lowlevel_init:
mov r12, lr
#if 0
/* LED on only #8 */
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x55540000
str r1, [r0, #GPNCON_OFFSET]
ldr r1, =0x55555555
str r1, [r0, #GPNPUD_OFFSET]
ldr r1, =0xf000
str r1, [r0, #GPNDAT_OFFSET]
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x1
str r1, [r0, #GPECON_OFFSET]
ldr r1, =0x0
str r1, [r0, #GPEDAT_OFFSET]
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x2A5AAAAA
str r1, [r0, #GPPCON_OFFSET]
ldr r1, =0x0
str r1, [r0, #GPPDAT_OFFSET]
ldr r1, =0x55555555
str r1, [r0, #MEM1DRVCON_OFFSET]
#endif
/* Disable Watchdog */
ldr r0, =0x7e000000 @0x7e004000
orr r0, r0, #0x4000
mov r1, #0
str r1, [r0]
@ External interrupt pending clear
ldr r0, =(ELFIN_GPIO_BASE+EINTPEND_OFFSET) /*EINTPEND*/
ldr r1, [r0]
str r1, [r0]
ldr r0, =ELFIN_VIC0_BASE_ADDR @0x71200000
ldr r1, =ELFIN_VIC1_BASE_ADDR @0x71300000
@ Disable all interrupts (VIC0 and VIC1)
mvn r3, #0x0
str r3, [r0, #oINTMSK]
str r3, [r1, #oINTMSK]
@ Set all interrupts as IRQ
mov r3, #0x0
str r3, [r0, #oINTMOD]
str r3, [r1, #oINTMOD]
@ Pending Interrupt Clear
mov r3, #0x0
str r3, [r0, #oVECTADDR]
str r3, [r1, #oVECTADDR]
/* init system clock */
bl system_clock_init
/* for UART */
bl uart_asm_init
#if defined(CONFIG_NAND)
/* simple init for NAND */
bl nand_asm_init
#endif
#if 0
ldr r0, =0xff000fff
bic r1, pc, r0 /* r0 <- current base addr of code */
ldr r2, _TEXT_BASE /* r1 <- original base addr in ram */
bic r2, r2, r0 /* r0 <- current base addr of code */
cmp r1, r2 /* compare r0, r1 */
beq 1f /* r0 == r1 then skip sdram init */
#endif
bl mem_ctrl_asm_init
#if 1
ldr r0, =(ELFIN_CLOCK_POWER_BASE+RST_STAT_OFFSET)
ldr r1, [r0]
bic r1, r1, #0xfffffff7
cmp r1, #0x8
beq wakeup_reset
#endif
1:
ldr r0, =ELFIN_UART_BASE
ldr r1, =0x4b4b4b4b
str r1, [r0, #UTXH_OFFSET]
mov lr, r12
mov pc, lr
#if 1
wakeup_reset:
/*Clear wakeup status register*/
ldr r0, =(ELFIN_CLOCK_POWER_BASE+WAKEUP_STAT_OFFSET)
ldr r1, [r0]
str r1, [r0]
/*LED test*/
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x3000
str r1, [r0, #GPNDAT_OFFSET]
/*Load return address and jump to kernel*/
ldr r0, =(ELFIN_CLOCK_POWER_BASE+INF_REG0_OFFSET)
ldr r1, [r0] /* r1 = physical address of s3c6400_cpu_resume function*/
mov pc, r1 /*Jump to kernel (sleep-s3c6400.S)*/
nop
nop
#endif
/*
* system_clock_init: Initialize core clock and bus clock.
* void system_clock_init(void)
*/
system_clock_init:
ldr r0, =ELFIN_CLOCK_POWER_BASE @0x7e00f000
#ifdef CONFIG_SYNC_MODE
ldr r1, [r0, #OTHERS_OFFSET]
mov r2, #0x40
orr r1, r1, r2
str r1, [r0, #OTHERS_OFFSET]
nop
nop
nop
nop
nop
ldr r2, =0x80
orr r1, r1, r2
str r1, [r0, #OTHERS_OFFSET]
check_syncack:
ldr r1, [r0, #OTHERS_OFFSET]
ldr r2, =0xf00
and r1, r1, r2
cmp r1, #0xf00
bne check_syncack
#else /* ASYNC Mode */
nop
nop
nop
nop
nop
ldr r1, [r0, #OTHERS_OFFSET]
bic r1, r1, #0xC0
orr r1, r1, #0x40
str r1, [r0, #OTHERS_OFFSET]
wait_for_async:
ldr r1, [r0, #OTHERS_OFFSET]
and r1, r1, #0xf00
cmp r1, #0x0
bne wait_for_async
ldr r1, [r0, #OTHERS_OFFSET]
bic r1, r1, #0x40
str r1, [r0, #OTHERS_OFFSET]
#endif
mov r1, #0xff00
orr r1, r1, #0xff
str r1, [r0, #APLL_LOCK_OFFSET]
str r1, [r0, #MPLL_LOCK_OFFSET]
str r1, [r0, #EPLL_LOCK_OFFSET]
/* CLKUART(=66.5Mhz) = CLKUART_input(532/2=266Mhz) / (UART_RATIO(3)+1) */
/* CLKUART(=50Mhz) = CLKUART_input(400/2=200Mhz) / (UART_RATIO(3)+1) */
/* Now, When you use UART CLK SRC by EXT_UCLK1, We support 532MHz & 400MHz value */
#if defined(CONFIG_CLKSRC_CLKUART)
ldr r1, [r0, #CLK_DIV2_OFFSET]
bic r1, r1, #0x70000
orr r1, r1, #0x30000
str r1, [r0, #CLK_DIV2_OFFSET]
#endif
ldr r1, [r0, #CLK_DIV0_OFFSET] /*Set Clock Divider*/
bic r1, r1, #0x30000
bic r1, r1, #0xff00
bic r1, r1, #0xff
ldr r2, =CLK_DIV_VAL
orr r1, r1, r2
str r1, [r0, #CLK_DIV0_OFFSET]
ldr r1, =APLL_VAL
str r1, [r0, #APLL_CON_OFFSET]
ldr r1, =MPLL_VAL
str r1, [r0, #MPLL_CON_OFFSET]
ldr r1, =0x80200203 /* FOUT of EPLL is 96MHz */
str r1, [r0, #EPLL_CON0_OFFSET]
ldr r1, =0x0
str r1, [r0, #EPLL_CON1_OFFSET]
ldr r1, [r0, #CLK_SRC_OFFSET] /* APLL, MPLL, EPLL select to Fout */
#if defined(CONFIG_CLKSRC_CLKUART)
ldr r2, =0x2007
#else
ldr r2, =0x7
#endif
orr r1, r1, r2
str r1, [r0, #CLK_SRC_OFFSET]
/* wait at least 200us to stablize all clock */
mov r1, #0x10000
1: subs r1, r1, #1
bne 1b
#if 0
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #0xc0000000 /* clock setting in MMU */
mcr p15, 0, r0, c1, c0, 0
#endif
#ifdef CONFIG_SYNC_MODE /* Synchronization for VIC port */
ldr r1, [r0, #OTHERS_OFFSET]
orr r1, r1, #0x20
str r1, [r0, #OTHERS_OFFSET]
#else
ldr r1, [r0, #OTHERS_OFFSET]
bic r1, r1, #0x20
str r1, [r0, #OTHERS_OFFSET]
#endif
mov pc, lr
/*
* uart_asm_init: Initialize UART in asm mode, 115200bps fixed.
* void uart_asm_init(void)
*/
uart_asm_init:
/* set GPIO to enable UART */
@ GPIO setting for UART
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x22222222
str r1, [r0, #GPACON_OFFSET]
ldr r1, =0x2222
str r1, [r0, #GPBCON_OFFSET]
ldr r0, =ELFIN_UART_CONSOLE_BASE @0x7F005000
mov r1, #0x0
str r1, [r0, #UFCON_OFFSET]
str r1, [r0, #UMCON_OFFSET]
mov r1, #0x3 @was 0.
str r1, [r0, #ULCON_OFFSET]
#if defined(CONFIG_CLKSRC_CLKUART)
ldr r1, =0xe45 /* UARTCLK SRC = 11 => EXT_UCLK1*/
#else
ldr r1, =0x245 /* UARTCLK SRC = x0 => PCLK */
#endif
str r1, [r0, #UCON_OFFSET]
#if defined(CONFIG_UART_50)
ldr r1, =0x1A
#elif defined(CONFIG_UART_66)
ldr r1, =0x22
#else
ldr r1, =0x1A
#endif
str r1, [r0, #UBRDIV_OFFSET]
#if defined(CONFIG_UART_50)
ldr r1, =0x3
#elif defined(CONFIG_UART_66)
ldr r1, =0x1FFF
#else
ldr r1, =0x3
#endif
str r1, [r0, #UDIVSLOT_OFFSET]
ldr r1, =0x4f4f4f4f
str r1, [r0, #UTXH_OFFSET] @'O'
mov pc, lr
/*
* Nand Interface Init for SMDK6400 */
nand_asm_init:
ldr r0, =ELFIN_NAND_BASE
ldr r1, [r0, #NFCONF_OFFSET]
orr r1, r1, #0x70
orr r1, r1, #0x7700
str r1, [r0, #NFCONF_OFFSET]
ldr r1, [r0, #NFCONT_OFFSET]
orr r1, r1, #0x03
str r1, [r0, #NFCONT_OFFSET]
mov pc, lr
#ifdef CONFIG_ENABLE_MMU
/*
* MMU Table for SMDK6400
*/
/* form a first-level section entry */
.macro FL_SECTION_ENTRY base,ap,d,c,b
.word (\base << 20) | (\ap << 10) | \
(\d << 5) | (1<<4) | (\c << 3) | (\b << 2) | (1<<1)
.endm
.section .mmudata, "a"
.align 14
// the following alignment creates the mmu table at address 0x4000.
.globl mmu_table
mmu_table:
.set __base,0
// 1:1 mapping for debugging
.rept 0xA00
FL_SECTION_ENTRY __base,3,0,0,0
.set __base,__base+1
.endr
// access is not allowed.
.rept 0xC00 - 0xA00
.word 0x00000000
.endr
// 128MB for SDRAM 0xC0000000 -> 0x50000000
.set __base, 0x500
.rept 0xC80 - 0xC00
FL_SECTION_ENTRY __base,3,0,1,1
.set __base,__base+1
.endr
// access is not allowed.
.rept 0x1000 - 0xc80
.word 0x00000000
.endr
#endif
start_armboot.c
/*
* gbing163@163.com
* 2012-7-9
*/
#include <s3c6410.h>
#include <stdio.h>
//#define DDR_TEST
#define TEST_LED
#ifdef DDR_TEST
static void TestDDR();
#endif
#ifdef TEST_LED
static void test_led();
#endif
void start_armboot()
{
printf("\r\n----------------------------\r\n");
#ifdef DDR_TEST
TestDDR();
#endif
#ifdef TEST_LED
test_led();
#endif
while(1)
{
printf("123.\r\n");
}
while(1);
}
#ifdef DDR_TEST
static void TestDDR()
{
unsigned int ddr_base = 0x50001000;
unsigned int i;
for(i = 0; i < 0x1000; i += 4)
{
*(unsigned int*)(ddr_base + i) = i;
if(*(unsigned int*)(ddr_base + i) != i)
{
*(unsigned int*)(ddr_base) = 0;
}
}
}
#endif
#ifdef TEST_LED
static void test_led()
{
int ledStatus = 0;
int i;
*(unsigned int*)(ELFIN_GPIO_BASE + GPKCON0_OFFSET) = 0x11110000;
while(1)
{
if(ledStatus)
{
*(unsigned int*)(ELFIN_GPIO_BASE + GPKDAT_OFFSET) = 0x00f0;
ledStatus = 0;
printf(".");
}
else
{
*(unsigned int*)(ELFIN_GPIO_BASE + GPKDAT_OFFSET) = 0x0000;
ledStatus = 1;
printf(".");
}
for(i = 0; i < 0x100000; i++);
}
}
#endif
gb6410.lds
/*
* gbing163@163.com
* 2012-7-9
*/
OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
/*OUTPUT_FORMAT("elf32-arm", "elf32-arm", "elf32-arm")*/
OUTPUT_ARCH(arm)
ENTRY(_start)
SECTIONS
{
. = 0x00000000;
. = ALIGN(4);
.text :
{
startup/start.o (.text)
startup/cpu_init.o (.text)
startup/lowlevel_init.o (.text)
startup/start_armboot.o (.text)
startup/putchar.o (.text)
*(.text)
}
. = ALIGN(4);
.rodata : { *(.rodata) }
. = ALIGN(4);
.data : { *(.data) }
. = ALIGN(4);
__bss_start = .;
.bss : { *(.bss) }
_end = .;
}
Makefile
#
# E-mail: gbing163@163.com
# Date: 2012-7-9
#
PROGNAME = gb6410
TOP_DIR := $(CURDIR)
export TOP_DIR
CC := arm-linux-gcc
CXX := arm-linux-g++
AR := arm-linux-ar
LD := arm-linux-ld
OBJCOPY := arm-linux-objcopy
#######################################################################################################
INC_DIR_OPT := \
-I$(TOP_DIR)/inc
CPPFLAGS := -g -Wall $(INC_DIR_OPT) -DTEXT_BASE=0x50000000
export CC CXX AR CPPFLAGS
########################################################################
SUBDIRS := $(TOP_DIR)/startup
#LIBS := $(TOP_DIR)/startup/libstartup.a
.PHONY: all $(SUBDIRS)
all: $(SUBDIRS)
$(LD) $(LDFLAGS) -o $(TOP_DIR)/$(PROGNAME) $(LIBS) -T gb6410.lds -Ttext 0x50000000 -Map gb6410.map
$(OBJCOPY) ${OBJCFLAGS} -O binary $(PROGNAME) $(PROGNAME).bin
@echo Success To Build Project.
$(SUBDIRS):
$(MAKE) -C $@ all
########################################################################
.PHONY:clean distclean cleanall
clean:
@for d in $(SUBDIRS); do \
$(MAKE) -C $$d clean; \
done
distclean cleanall:
@for d in $(SUBDIRS); do \
$(MAKE) -C $$d distclean; \
done
$(RM) $(PROGNAME)
运行程序，在终端可以看到打印字符，板子上LED闪烁。