mini6410移植全攻略（4）--uboot移植之支持nand flansh启动(中)

四、修改有关的信息：

本文章由muge0913编写，仅供技术交流转载请注明出处：

http://blog.csdn.net/muge0913/article/details/7168325

1、

串口中打印出来的信息大多数来自board.c文件

print_cpuinfo函数在/*arch/arm/cpu/arm1176/s3c64xx/speed.c*/实现

更改相应的信息即可。

2、checkboard函数在/*board/samsung/th6410/th6410.c*/实现，更改相应的信息即可。

3、同时屏蔽

	env_init,		/* initialize environment */
	init_baudrate,		/* initialze baudrate settings */
//	serial_init,		/* serial communications setup */
	console_init_f,		/* stage 1 init of console */
	display_banner,		/* say that we are here */

串口初始化在lowlevel_init.S中实现，其代码如下，这是经过修改后的代码，因为工作量问题我们不再具体讲述。

五、lovlevel_init.S代码分析：

#include <config.h>
#include <version.h>

#include <asm/arch/s3c6400.h>

#ifdef CONFIG_SERIAL1
#define ELFIN_UART_CONSOLE_BASE (ELFIN_UART_BASE + ELFIN_UART0_OFFSET)
#elif defined(CONFIG_SERIAL2)
#define ELFIN_UART_CONSOLE_BASE (ELFIN_UART_BASE + ELFIN_UART1_OFFSET)
#else
#define ELFIN_UART_CONSOLE_BASE (ELFIN_UART_BASE + ELFIN_UART2_OFFSET)
#endif

_TEXT_BASE:
	.word	TEXT_BASE

	.globl lowlevel_init
lowlevel_init:
	mov	r12, lr

	/* LED on only #8 在这里我们不做处理*/

	/* 禁止看门狗*/
	ldr	r0, =0x7e000000		@0x7e004000
	orr	r0, r0, #0x4000
	mov	r1, #0
	str	r1, [r0]

	/*禁止外部中断*/
	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

	mvn	r3, #0x0
	str	r3, [r0, #oINTMSK]
	str	r3, [r1, #oINTMSK]

	@ 设置IRQ
	mov	r3, #0x0
	str	r3, [r0, #oINTMOD]
	str	r3, [r1, #oINTMOD]

	mov	r3, #0x0
	str	r3, [r0, #oVECTADDR]
	str	r3, [r1, #oVECTADDR]

	/* 初始化系统时钟 */
	bl system_clock_init

	/* 初始化串口 */
	bl uart_asm_init

#if defined(CONFIG_NAND)
	/* simple init for NAND */
	bl nand_asm_init
#endif
       /*初始化存储控制*/
	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

本文章由muge0913编写，仅供技术交流转载请注明出处

http://blog.csdn.net/muge0913/article/details/7168325