U-Boot1.3.1移植YC2440
U-Boot1.3.1移植YC2440
ARM and Linux，一个伟大的行业，鄙人正处于摸索阶段的新手。既然如此，就先从U-Boot下手，在此过程中参考了网上一些高手的资料。下面是他们的链接，感谢他们分享经验让新手快速入门、找到学习方法，再次感谢他们对于技术资料无私奉献、共享。
由于YC2440网卡芯片DM9000AEP，网卡移植参考了Weibing的一位网友。
U-Boot源码：
U-Boot源码下载
免费下载地址在 http://linux.bkjia.com/
用户名与密码都是www.bkjia.com
具体下载目录在 /pub/u-boot/
U-Boot-
一、在U-Boot中建立自己开发板类型，测试编译
1 进入U-Boot目录，修改Makefile
# tar –jxvf u-boot-
# cd u-boot-
# gedit Makefile
//为liao2440建立编译项
sbc2410x_config: unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t sbc2410x NULL s
liao2440_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t liao2440 liao s
说明：
arm: CPU的架构(ARCH)
arm920t: CPU的类型(CPU)，其对应于cpu/arm920t子目录。
liao2440: 开发板的型号(BOARD)，对应于board/liao/liao2440目录。
liao: 开发者/或经销商(vender)。
s
同时在“ifndef CROSS_COMPILE”之前 加上自己交叉编译器的路径，比如我使用crosstool-0.43制作的基于
CROSS_COMPILE=CROSS_COMPILE=/home/liao/crosstool/gcc-
2 /board子目录中建立自己开发板liao2440目录
由于上一步板子的开发者/或经销商(vender)中填了liao，所以开发板liao2440目录一定要建在/board子目录liao目录下 ，否则编译会出错。
# cd board
# mkdir liao liao/liao2440
# cp -arf sbc2410x/* liao/liao2440/
# cd liao/liao2440
# mv sbc2410x.c liao2440.c
修改自己开发板liao2440目录下Makefile文件
# gedit Makefile
COBJS := sbc2410x.o flash.o
COBJS := liao2440.o flash.o
3 建立配置头文件在include/configs/
# cd …/u-boot-
# cp include/configs/sbc2410x.h include/configs/liao2440.h
4 测试编译是否成功
# make liao2440_config
Configuring for liao2440 board…
(如果出现：
Makefile:1927: *** 遗漏分隔符 。 停止。
请在U－boot的根目录下的Makefile的
@$(MKCONFIG) $(@:_config=) arm arm920t liao2440 liao)
前加上“Tab”键)
# make
Ok，到这里前期准备工作完成！！！！！！！
二、修改U-Boot中文件，根据开发板YC2440配置
1 修改/cpu/arm920t/start.S
1.0 修改一些AT91RM9200定义
#include <config.h>
#include <version.h>
//#include <status_led.h> /*这是针对AT91RM9200DK开发板*/
......
/*
* the actual start code
*/
start_code:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x
orr r0,r0,#0xd3
msr cpsr,r0
//bl coloured_LED_init
//bl red_LED_on
1.1修改寄存器定义
#if defined(CONFIG_S
/* turn off the watchdog */
# if defined(CONFIG_S
# define pWTCON 0x15300000
# define INTMSK 0x14400008 /* Interupt-Controller base addresses */
# define CLKDIVN 0x14800014 /* clock divisor register */
# else
# define pWTCON 0x53000000
# define INTMSK 0x
# define INTSUBMSK 0x
# define CLKDIVN 0x
# endif
# define CLK_CTL_BASE 0x
# if defined(CONFIG_S
# define MDIV_405 0x
# define PSDIV_405 0x21
# endif
# if defined(CONFIG_S
# define MDIV_200 0xa1 << 12
# define PSDIV_200 0x31
# endif
/*这一段为后面修改时钟定义的一些参数*/
1.2修改中断禁止部分
# if defined(CONFIG_S
ldr r0, =pWTCON
mov r1, #0x0
str r1, [r0]
/*
* mask all IRQs by setting all bits in the INTMR - default
*/
mov r1, #0xffffffff
ldr r0, =INTMSK
str r1, [r0]
# if defined(CONFIG_S
ldr r1, =0x7ff //根据2410芯片手册，INTSUBMSK有11位可用，
//vivi也是0x7ff，不知为什么U－Boot一直没改过来。
ldr r0, =INTSUBMSK
str r1, [r0]
# endif
# if defined(CONFIG_S
ldr r1, =0x7fff //根据2440芯片手册，INTSUBMSK有15位可用
ldr r0, =INTSUBMSK
str r1, [r0]
# endif
1.3 修改时钟设置
/*时钟控制逻辑单元能够产生s
/* FCLK:HCLK:PCLK = 1:4:8 */
ldr r0, =CLKDIVN
mov r1, #5
str r1, [r0]
/*
下面协处理器指令是用来把CPU的模式设置成Asynchronous 模式，为什么要这样做？s
单从指令上看，下面指令的作用把协处理器p15的寄存器c1的最高两位置1，仔细看过《arm 体系结构与编程》的朋友可能会发现个问题：《arm 体系结构与编程》里面说 p15 的bit30和bit31是保留的，那么下面的指令又怎么会有意义呢？其实《arm 体系结构与编程》里面说这两个bit是保留的是针对arm7的，对arm9的s
*/
mrc p15, 0, r1, c1, c0, 0 /*read ctrl register liao*/
orr r1, r1, #0xc0000000 /*Asynchronous liao*/
mcr p15, 0, r1, c1, c0, 0 /*write ctrl register liao*/
# if defined(CONFIG_S
/*now, CPU clock is 405.00 Mhz */
mov r1, #CLK_CTL_BASE
mov r2, #MDIV_405 /* mpll_405mhz liao*/
add r2, r2, #PSDIV_405 /* mpll_405mhz liao*/
str r2, [r1, #0x04] /* MPLLCON liao */
# endif
# if defined(CONFIG_S
/*now, CPU clock is 202.8 Mhz liao*/
mov r1, #CLK_CTL_BASE /* liao*/
mov r2, #MDIV_200 /* mpll_200mhz liao*/
add r2, r2, #PSDIV_200 /* mpll_200mhz liao*/
str r2, [r1, #0x04] /* MPLLCON liao */
# endif
# endif /* CONFIG_S
/*时钟设置参照vivi代码，主频405MHZ*/
1.4 将Flash启动改为从NAND Flash启动（2410与2440不同，参照vivi）
# if 0
# ifndef CONFIG_SKIP_RELOCATE_UBOOT
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
# endif /* CONFIG_SKIP_RELOCATE_UBOOT */
# endif
/*参照vivi代码，nandflash拷贝*/
# ifdef CONFIG_S
@ reset NAND
mov r1, #NAND_CTL_BASE
ldr r2, =( (7<<12)|(7<<8)|(7<<4)|(0<<0) )
str r2, [r1, #oNFCONF] /*这些宏在includes/configs/liao2440.h中定义*/
ldr r2, [r1, #oNFCONF]
ldr r2, =( (1<<4)|(0<<1)|(1<<0) ) @ Active low CE Control
str r2, [r1, #oNFCONT]
ldr r2, [r1, #oNFCONT]
ldr r2, =(0x6) @ RnB Clear
str r2, [r1, #oNFSTAT]
ldr r2, [r1, #oNFSTAT]
mov r2, #0xff @ RESET command
strb r2, [r1, #oNFCMD]
mov r3, #0 @ wait
nand1:
add r3, r3, #0x1
cmp r3, #0xa
blt nand1
nand2:
ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x4
beq nand2
ldr r2, [r1, #oNFCONT]
orr r2, r2, #0x2 @ Flash Memory Chip Disable
str r2, [r1, #oNFCONT]
/*汇编调用C函数，初始化栈*/
@ get read to call C functions (for nand_read())
ldr sp, DW_STACK_START @ setup stack pointer
mov fp, #0 @ no previous frame, so fp=0
@ copy U-Boot to RAM
ldr r0, =TEXT_BASE
mov r1, #0x0
mov r2, #0x30000
bl nand_read_ll
/*nand_read_ll为uboot拷贝代码入口函数，r0，r1，r2为入口参数
tst r0，#0x0中r0为函数返回值*/
tst r0, #0x0
beq ok_nand_read
bad_nand_read:
loop2: b loop2 @ infinite loop
ok_nand_read:
@ verify
mov r0, #0
ldr r1, =TEXT_BASE
mov r2, #0x400 @ 4 bytes * 1024 = 4K-bytes
go_next:
ldr r3, [r0], #4
ldr r4, [r1], #4
teq r3, r4
bne notmatch
subs r2, r2, #4
beq stack_setup
bne go_next
notmatch:
loop3: b loop3 @ infinite loop
#endif @ CONFIG_S
#ifdef CONFIG_S
@ reset NAND
mov r1, #NAND_CTL_BASE
ldr r2, =0xf830 @ initial value
str r2, [r1, #oNFCONF]
ldr r2, [r1, #oNFCONF]
bic r2, r2, #0x800 @ enable chip
str r2, [r1, #oNFCONF]
mov r2, #0xff @ RESET command
strb r2, [r1, #oNFCMD]
mov r3, #0 @ wait
nand1:
add r3, r3, #0x1
cmp r3, #0xa
blt nand1
nand2:
ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x1
beq nand2
ldr r2, [r1, #oNFCONF]
orr r2, r2, #0x800 @ disable chip
str r2, [r1, #oNFCONF]
@ get read to call C functions (for nand_read())
ldr sp, DW_STACK_START @ setup stack pointer
mov fp, #0 @ no previous frame, so fp=0
@ copy U-Boot to RAM
ldr r0, =TEXT_BASE
mov r1, #0x0
mov r2, #0x30000
bl nand_read_ll
tst r0, #0x0
beq ok_nand_read
bad_nand_read:
loop2: b loop2 @ infinite loop
ok_nand_read:
@ verify
mov r0, #0
ldr r1, =TEXT_BASE
mov r2, #0x400 @ 4 bytes * 1024 = 4K-bytes
go_next:
ldr r3, [r0], #4
ldr r4, [r1], #4
teq r3, r4
bne notmatch
subs r2, r2, #4
beq stack_setup
bne go_next
notmatch:
loop3: b loop3 @ infinite loop
#endif @ CONFIG_S
1.5 调出start.S前，利用点灯大法查看程序运行位置
在 ldr pc，_start_armboot 之前加入LED
mov r1, #GPIO_CTL_BASE
add r1, r1, #oGPIO_F
ldr r2,=0x55aa
str r2, [r1, #oGPIO_CON]
mov r2, #0xff
str r2, [r1, #oGPIO_UP]
mov r2, #0xe0
str r2, [r1, #oGPIO_DAT]
/*YC2440开发板有4个LED，GPIO_F[4:7]，点亮一个LED，下面函数进入第二阶段*/
ldr pc，_start_armboot
_start_armboot: .word start_armboot
.align 2
DW_STACK_START: .word STACK_BASE+STACK_SIZE-4
/*栈空间是从高地址向低地址增长，用于调用nand_read_ll函数时设置占空间，STACK_BASE STACK_SIZE定义在后面/include/configs/liao2440.h */
2 在board/liao/liao2440加入NAND Flash读函数文件，复制vivi中nand_read.c文件
#include <config.h>
#define __REGb(x) (*(volatile unsigned char *)(x))
#define __REGi(x) (*(volatile unsigned int *)(x))
#define NF_BASE 0x4e000000
#if defined(CONFIG_S
#define NFCONF __REGi(NF_BASE + 0x0)
#define NFCONT __REGi(NF_BASE + 0x4)
#define NFCMD __REGb(NF_BASE + 0x8)
#define NFADDR __REGb(NF_BASE + 0xC)
#define NFDATA __REGb(NF_BASE + 0x10)
#define NFSTAT __REGb(NF_BASE + 0x20)
//#define GPDAT __REGi(GPIO_CTL_BASE+oGPIO_F+oGPIO_DAT)
#define NAND_CHIP_ENABLE (NFCONT &= ~(1<<1))
#define NAND_CHIP_DISABLE (NFCONT |= (1<<1))
#define NAND_CLEAR_RB (NFSTAT |= (1<<2))
#define NAND_DETECT_RB { while(! (NFSTAT&(1<<2)) );}
#define BUSY 4
inline void wait_idle(void) {
while(!(NFSTAT & BUSY));
NFSTAT |= BUSY;
}
#define NAND_SECTOR_SIZE 512
#define NAND_BLOCK_MASK (NAND_SECTOR_SIZE - 1)
/* low level nand read function */
int
nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
int i, j;
/*
下面if保证对flash的读操作是从某一页的页头开始的，也就是保证start_addr[0:8]位都为0，
本次flash的一页的大小位512-bytes，也就是从0x0到0x1ff */
if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
return -1; /* invalid alignment */
}
NAND_CHIP_ENABLE;
for(i=start_addr; i < (start_addr + size);) {
/* READ0 */
NAND_CLEAR_RB;
NFCMD = 0;
/* Write Address */
/*下面这个送地址的过程最难懂的一部分，为什么送进nand flash的地址忽略了bit8，纵观整个for(i) 循环，i并不是一个随机的地址，而应该是每一页的首地址。其实nand flash并不是忽略了bit8这个地址，而是bit8早就被定下来了，就是上面的NFCMD = 0;语句，(K
NFADDR = i & 0xff;
NFADDR = (i >> 9) & 0xff;
NFADDR = (i >> 17) & 0xff;
NFADDR = (i >> 25) & 0xff;
NAND_DETECT_RB;
for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
*buf = (NFDATA & 0xff);
buf++;
}
}
NAND_CHIP_DISABLE;
return 0;
}
#endif
#if defined(CONFIG_S
#define NFCONF __REGi(NF_BASE + 0x0)
#define NFCMD __REGb(NF_BASE + 0x4)
#define NFADDR __REGb(NF_BASE + 0x8)
#define NFDATA __REGb(NF_BASE + 0xc)
#define NFSTAT __REGb(NF_BASE + 0x10)
#define BUSY 1
inline void wait_idle(void) {
int i;
while(!(NFSTAT & BUSY))
for(i=0; i<10; i++);
}
/* low level nand read function */
int
nand_read_ll(unsigned char *buf, unsigned long start_addr, int size)
{
int i, j;
if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
return -1; /* invalid alignment */
}
/* chip Enable */
NFCONF &= ~0x800;
for(i=0; i<10; i++);
for(i=start_addr; i < (start_addr + size);)
{
/* READ0 */
NFCMD = 0;
/* Write Address */
NFADDR = i & 0xff;
NFADDR = (i >> 9) & 0xff;
NFADDR = (i >> 17) & 0xff;
NFADDR = (i >> 25) & 0xff;
wait_idle();
for(j=0; j < NAND_SECTOR_SIZE; j++, i++)
{
*buf = (NFDATA & 0xff);
buf++;
}
}
/* chip Disable */
NFCONF |= 0x800; /* chip disable */
return 0;
}
# endif
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