(一)
(1)、建立自己s3c2410开发板的配置
1)# cp –r board/smdk2410 board/s3c2410
2)# cp include/configs/smdk2410.h include/configs/s3c2410.h
s3c2410.h是开发板的配置文件,他包括开发板的CPU、系统时钟、RAM、FLASH系统及其他相关的配置信息,由于u-boot已经支持三星的SMDK2410开发板,所以移植的时候直接拷贝SMDK2410的配置文件,做相应的修改即可。由于Uboot对SMDK2410板的NAND Flash初始化部分没有写,即lib_arm/board.c中的start_armboot函数中有这么一句:
#if (CONFIG_COMMANDS & CFG_CMD_NAND)
puts ("NAND:");
nand_init();
#endif
但是在board/smdk2410目录下源文件中都没有定义nand_init这个函数。所以需要我们补充这个函数以及这个函数涉及的底层操作,NAND Flash的读写操作相对复杂,将在u-boot- 1.1.6移植的第二部分介绍。
(2). 修改顶层Makefile
cd /uboot/u-boot-1.1.6
vi Makefile
找到:
smdk2410_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0
在其后面添加:
s3c2410_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t s3c2410 NULL s3c24x0
各项的意思如下:
arm: CPU的架构(ARCH)
arm920t: CPU的类型(CPU),其对应于cpu/arm920t子目录。
s3c2410: 开发板的型号(BOARD),对应于board/s3c2410目录。
NULL: 开发者/或经销商(vender)。
s3c24x0: 片上系统(SOC)。
(3). include/configs/s3c2410.h:
修改:
# define CFG_PROMPT “SMDK2410 #”
为:
# define CFG_PROMPT “GUET2410 #”
这是u-boot的命令行提示符。
(4) 修改board/s3c2410/Makefile
将:
OBJS := smdk2410.o flash.o
改为:
OBJS := s3c2410.o flash.o
当然,s3c2410下的 smdk2410.c要改成s3c2410.c;
(5)依照你自己开发板的内存地址分配情况修改board/s3c2410/lowlevel_init.S文件
这里我参考了FS2410开发板自带S3C2410_BIOS,代码如下:
#include <config.h>
#include <version.h>
#define BWSCON 0x48000000
#define DW8 (0x0)
#define DW16 (0x1)
#define DW32 (0x2)
#define WAIT (0x1<<2)
#define UBLB (0x1<<3)
#define B1_BWSCON (DW16)
#define B2_BWSCON (DW16)
#define B3_BWSCON (DW16 + WAIT + UBLB)
#define B4_BWSCON (DW16)
#define B5_BWSCON (DW16)
#define B6_BWSCON (DW32)
#define B7_BWSCON (DW32)
#define B0_Tacs 0x3
#define B0_Tcos 0x3
#define B0_Tacc 0x7
#define B0_Tcoh 0x3
#define B0_Tah 0x3
#define B0_Tacp 0x1
#define B0_PMC 0x0
#define B1_Tacs 0x3
#define B1_Tcos 0x3
#define B1_Tacc 0x7
#define B1_Tcoh 0x3
#define B1_Tah 0x3
#define B1_Tacp 0x3
#define B1_PMC 0x0
#define B2_Tacs 0x0
#define B2_Tcos 0x0
#define B2_Tacc 0x7
#define B2_Tcoh 0x0
#define B2_Tah 0x0
#define B2_Tacp 0x0
#define B2_PMC 0x0
#define B3_Tacs 0x0
#define B3_Tcos 0x3
#define B3_Tacc 0x7
#define B3_Tcoh 0x1
#define B3_Tah 0x0
#define B3_Tacp 0x3
#define B3_PMC 0x0
#define B4_Tacs 0x1
#define B4_Tcos 0x1
#define B4_Tacc 0x6
#define B4_Tcoh 0x1
#define B4_Tah 0x1
#define B4_Tacp 0x0
#define B4_PMC 0x0
#define B5_Tacs 0x1
#define B5_Tcos 0x1
#define B5_Tacc 0x6
#define B5_Tcoh 0x1
#define B5_Tah 0x1
#define B5_Tacp 0x0
#define B5_PMC 0x0
#define B6_MT 0x3
#define B6_Trcd 0x1
#define B6_SCAN 0x1
#define B7_MT 0x3
#define B7_Trcd 0x1
#define B7_SCAN 0x1
#define REFEN 0x1
#define TREFMD 0x0
#define Trp 0x0
#define Trc 0x3
#define Tchr 0x2
#define REFCNT 1113
(6)在board/s3c2410加入NAND Flash读函数,建立nand_read.c,加入如下内容(copy from vivi):
#include <config.h>
#include "linux/mtd/mtd.h"
#include "linux/mtd/nand.h"
#define __REGb(x) (*(volatile unsigned char *)(x))
#define __REGi(x) (*(volatile unsigned int *)(x))
#define NF_BASE 0x4e000000
#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++);
}
#define NAND_SECTOR_SIZE 512
#define NAND_BLOCK_MASK (NAND_SECTOR_SIZE - 1)
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;
}
NFCONF &= ~0x800;
for(i=0; i<10; i++);
for(i=start_addr; i < (start_addr + size);) {
NFCMD = 0;
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++;
}
}
NFCONF |= 0x800;
return 0;
}
(7)修改cpu/arm920t/start.S文件
2410的启动代码可以在外部的NAND FLASH上执行,启动时,NAND FLASH的前4KB(地址为0x00000000,OM[1:0]=0)将被装载到SDRAM中被称为Setppingstone的地址中,然后开始执行这段代码。启动以后,这4KB的空间可以做其他用途,在start.S加入搬运代码如下:
...........
...........
copy_loop:
ldmia r0!, {r3-r10}
stmia r1!, {r3-r10}
cmp r0, r2
ble copy_loop
#ifdef CONFIG_S3C2410_NAND_BOOT
bl copy_myself
#endif
#endif
stack_setup:
..................
#ifdef CONFIG_S3C2410_NAND_BOOT
copy_myself:
mov r10, lr
@ 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
1: add r3, r3, #0x1
cmp r3, #0xa
blt 1b
2: ldr r2, [r1, #oNFSTAT] @ wait ready
tst r2, #0x1
beq 2b
ldr r2, [r1, #oNFCONF]
orr r2, r2, #0x800 @ disable chip
str r2, [r1, #oNFCONF]
@ get read to call C functions
ldr sp, DW_STACK_START @ setup stack pointer
mov fp, #0 @ no previous frame, so fp=0
@ copy UBOOT to RAM
ldr r0, _TEXT_BASE
mov r1, #0x0
mov r2, #0x20000
bl nand_read_ll
teq r0, #0x0
beq ok_nand_read
bad_nand_read:
1: b 1b @ 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 done_nand_read
bne go_next
notmatch:
1: b 1b
done_nand_read:
mov pc, r10
#endif
@ CONFIG_S3C2440_NAND_BOOT
DW_STACK_START:
.word STACK_BASE+STACK_SIZE-4
(8)修改include/configs/s3c2410.h文件,添加如下内容:
#define CONFIG_S3C2410_NAND_BOOT 1
#define STACK_BASE 0x33f00000
#define STACK_SIZE 0x8000
#define UBOOT_RAM_BASE 0x30100000
#define NAND_CTL_BASE 0x4e000000
#define bINT_CTL(Nb) _REG(INT_CTL_BASE+(Nb))
#define oNFCONF 0x00
#define oNFCMD 0x04
#define oNFADDR 0x08
#define oNFDATA 0x0c
#define oNFSTAT 0x10
#define oNFECC 0x14
#define NAND_MAX_CHIPS 1
(9)修改board/s3c2410/Makefile
OBJS := s3c2410.o flash.o nand_read.o
(二)
一、代码搬运
u-boot启动时,需要 copy u-boot to ram 的过程,通过自己定义的 nand_read.c实现,该步骤与u-boot- 1.1.6移植(一)同,需要注意的是增加对nand flash支持后编译出来的bin文件将大于128KB,所以修改start.S即可:
@ copy UBOOT to RAM
ldr r0, _TEXT_BASE
mov r1, #0x0
mov r2, #0x20000 //改为mov r2,#0x40000,这是FS2410分配给u-boot的存储空间
bl nand_read_ll
二、修改配置文件 include/configs/s3c2410.h 使支持NAND
#define CONFIG_COMMANDS \
(CONFIG_CMD_DFL | \
CFG_CMD_CACHE | \
CFG_CMD_ENV | \
CFG_CMD_NET | \
CFG_CMD_PING | \
CFG_CMD_NAND | \
\
\
\
CFG_CMD_REGINFO | \
CFG_CMD_DATE | \
CFG_CMD_ELF)
#define CFG_NAND_BASE 0x4E000000
#define CFG_MAX_NAND_DEVICE 1
#define NAND_MAX_CHIPS 1
#define CFG_ENV_IS_IN_NAND 1
#define CMD_SAVEENV
#define CFG_ENV_SIZE 0x10000
#define CFG_ENV_OFFSET 0x30000
#define CONFIG_BOOTDELAY 3
#define CONFIG_BOOTARGS "noinitrd root=/dev/mtdblock2 init=/linuxrc devfs=mount console=ttySAC0,115200"
#define CONFIG_ETHADDR 08:00:3e:26:0a:5b
#define CONFIG_NETMASK 255.255.255.0
#define CONFIG_IPADDR 202.193.74.101
#define CONFIG_SERVERIP 202.193.74.235
#define CONFIG_BOOTCOMMAND "nand read 0x30007fc0 0x40000 0x1c0000; bootm 0x30007fc0"
三、建立cpu/arm920t/s3c24x0/nand_flash.c,实现board_nand_init函数
《嵌入式Linux应用开发完全手册》中介召的nand_flash.c包含对S3C2440的支持,在这里一并列出,供日后参考。
(1)针对S3C2410、S3C2440 NAND Flash控制器的不同来定义一些数据结构和函数,在include/s3c24x0.h 文件中增加S3C2440_NAND数据结构。
typedef struct {
S3C24X0_REG32 NFCONF;
S3C24X0_REG32 NFCONT;
S3C24X0_REG32 NFCMD;
S3C24X0_REG32 NFADDR;
S3C24X0_REG32 NFDATA;
S3C24X0_REG32 NFMECCD0;
S3C24X0_REG32 NFMECCD1;
S3C24X0_REG32 NFSECCD;
S3C24X0_REG32 NFSTAT;
S3C24X0_REG32 NFESTAT0;
S3C24X0_REG32 NFESTAT1;
S3C24X0_REG32 NFMECC0;
S3C24X0_REG32 NFMECC1;
S3C24X0_REG32 NFSECC;
S3C24X0_REG32 NFSBLK;
S3C24X0_REG32 NFEBLK;
} S3C2440_NAND;
(2)在 include/s3c2410.h 文件中仿照 S3C2410_GetBase_NAND函数定义S3C2440_GetBase_NAND函数。
static inline S3C2440_NAND * const S3C2440_GetBase_NAND(void)
{
return (S3C2440_NAND * const)S3C2410_NAND_BASE;
}
(3) cpu/arm920t/s3c24x0/nand_flash.c,添加nand_flash.c文件
#include <common.h>
#if (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined(CFG_NAND_LEGACY)
#include <s3c2410.h>
#include <nand.h>
DECLARE_GLOBAL_DATA_PTR;
#define S3C2410_NFSTAT_READY (1<<0)
#define S3C2410_NFCONF_nFCE (1<<11)
#define S3C2440_NFSTAT_READY (1<<0)
#define S3C2440_NFCONT_nFCE (1<<1)
static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
{
S3C2410_NAND * const s3c2410nand = S3C2410_GetBase_NAND();
if (chip == -1) {
s3c2410nand->NFCONF |= S3C2410_NFCONF_nFCE;
} else {
s3c2410nand->NFCONF &= ~S3C2410_NFCONF_nFCE;
}
}
static void s3c2410_nand_hwcontrol(struct mtd_info *mtd, int cmd)
{
S3C2410_NAND * const s3c2410nand = S3C2410_GetBase_NAND();
struct nand_chip *chip = mtd->priv;
switch (cmd) {
case NAND_CTL_SETNCE:
case NAND_CTL_CLRNCE:
printf("%s: called for NCE\n", __FUNCTION__);
break;
case NAND_CTL_SETCLE:
chip->IO_ADDR_W = (void *)&s3c2410nand->NFCMD;
break;
case NAND_CTL_SETALE:
chip->IO_ADDR_W = (void *)&s3c2410nand->NFADDR;
break;
default:
chip->IO_ADDR_W = (void *)&s3c2410nand->NFDATA;
break;
}
}
static int s3c2410_nand_devready(struct mtd_info *mtd)
{
S3C2410_NAND * const s3c2410nand = S3C2410_GetBase_NAND();
return (s3c2410nand->NFSTAT & S3C2410_NFSTAT_READY);
}
static void s3c2440_nand_select_chip(struct mtd_info *mtd, int chip)
{
S3C2440_NAND * const s3c2440nand = S3C2440_GetBase_NAND();
if (chip == -1) {
s3c2440nand->NFCONT |= S3C2440_NFCONT_nFCE;
} else {
s3c2440nand->NFCONT &= ~S3C2440_NFCONT_nFCE;
}
}
static void s3c2440_nand_hwcontrol(struct mtd_info *mtd, int cmd)
{
S3C2440_NAND * const s3c2440nand = S3C2440_GetBase_NAND();
struct nand_chip *chip = mtd->priv;
switch (cmd) {
case NAND_CTL_SETNCE:
case NAND_CTL_CLRNCE:
printf("%s: called for NCE\n", __FUNCTION__);
break;
case NAND_CTL_SETCLE:
chip->IO_ADDR_W = (void *)&s3c2440nand->NFCMD;
break;
case NAND_CTL_SETALE:
chip->IO_ADDR_W = (void *)&s3c2440nand->NFADDR;
break;
default:
chip->IO_ADDR_W = (void *)&s3c2440nand->NFDATA;
break;
}
}
static int s3c2440_nand_devready(struct mtd_info *mtd)
{
S3C2440_NAND * const s3c2440nand = S3C2440_GetBase_NAND();
return (s3c2440nand->NFSTAT & S3C2440_NFSTAT_READY);
}
static void s3c24x0_nand_inithw(void)
{
S3C2410_NAND * const s3c2410nand = S3C2410_GetBase_NAND();
S3C2440_NAND * const s3c2440nand = S3C2440_GetBase_NAND();
#define TACLS 0
#define TWRPH0 4
#define TWRPH1 2
if (gd->bd->bi_arch_number == MACH_TYPE_SMDK2410)
{
s3c2410nand->NFCONF = (1<<15)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0);
}
else
{
s3c2440nand->NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);
s3c2440nand->NFCONT = (1<<4)|(0<<1)|(1<<0);
}
}
void board_nand_init(struct nand_chip *chip)
{
S3C2410_NAND * const s3c2410nand = S3C2410_GetBase_NAND();
S3C2440_NAND * const s3c2440nand = S3C2440_GetBase_NAND();
s3c24x0_nand_inithw();
if (gd->bd->bi_arch_number == MACH_TYPE_SMDK2410) {
chip->IO_ADDR_R = (void *)&s3c2410nand->NFDATA;
chip->IO_ADDR_W = (void *)&s3c2410nand->NFDATA;
chip->hwcontrol = s3c2410_nand_hwcontrol;
chip->dev_ready = s3c2410_nand_devready;
chip->select_chip = s3c2410_nand_select_chip;
chip->options = 0;
} else {
chip->IO_ADDR_R = (void *)&s3c2440nand->NFDATA;
chip->IO_ADDR_W = (void *)&s3c2440nand->NFDATA;
chip->hwcontrol = s3c2440_nand_hwcontrol;
chip->dev_ready = s3c2440_nand_devready;
chip->select_chip = s3c2440_nand_select_chip;
chip->options = 0;
}
chip->eccmode = NAND_ECC_SOFT;
}
#endif
四、将nand_flash.c编入 u-boot,修改cpu/arm920t/s3c24x0/Makefile文件
COBJS = i2c.o interrupts.o serial.o speed.o \
usb_ohci.o nand_flash.o
至此,编译生成 u-boot.bin 并烧入NAND Flash,启动,便可以引导内核了。
(三)
1、U-BOOT给linux内核传递合适参数的定义
修改include/configs/s3c2410.h如下:
……
……
#define CONFIG_RTC_S 3C24X0 1
#define CONFIG_ENV_OVERWRITE
#define CONFIG_BAUDRATE 115200
#define CONFIG_CMDLINE_TAG 1
#define CONFIG_SETUP_MEMORY_TAGS 1
#define CONFIG_INITRD_TAG 1
2、修改UBOOT的2410CPU频率
smdk2410的U-BOOT原来运行频率是202.8M,而FS2410的BIOS里面是200M,所以不修改频率可能会出点问题。按照网上的说法,内核中,在\arch\arm\mach_s3c2410\s3c2410.c 中,fclk = s3c2410_get_pll(MPLLCON, xtal); //读出来的fclk结果和bootloader的频率不一致。
修改board/s3c2410/s3c2410.c文件如下:
#define FCLK_SPEED 1
#if FCLK_SPEED==0
#define M_MDIV 0xC3
#define M_PDIV 0x4
#define M_SDIV 0x1
#elif FCLK_SPEED==1
//#define M_MDIV 0xA1
//#define M_PDIV 0x3
//#define M_SDIV 0x1
#define M_MDIV 0x5c
#define M_PDIV 0x4
#define M_SDIV 0x0
#endif
3、修改include/configs/s3c2410.h中的CFG_LOAD_ADDR的地址为0x30007FC0
这是内核的加载地址,board/smdk2410/config.mk文件注释中提到Linux内核希望自己被加载到0x30008000的内存地址,而由于uImage会在kernel镜像之前加上大小为0x40的头文件消息,所以需要减去0x40。
(四)
u-boot- 1.1.6已经可以通过"nand write..."、"nand write.jffs2..."等命令来烧写cramfs、jffs2文件系统映象文件,下面增加"nand write.yaffs..."命令实现yaffs文件系统映象的烧写。
1、在commom/cmd_nand.c中增加"nand write.yaffs..." 的使用说明,代码添加如下:
U_BOOT_CMD(nand, 5, 1, do_nand,
"nand - NAND sub-system\n",
"info - show available NAND devices\n"
"nand device [dev] - show or set current device\n"
"nand read[.jffs2] - addr off|partition size\n"
"nand write[.jffs2] - addr off|partiton size - read/write `size' bytes starting\n"
" at offset `off' to/from memory address `addr'\n"
"nand read.yaffs addr off size - read the `size' byte yaffs image starting\n"
" at offset `off' to memory address `addr'\n"
"nand write.yaffs addr off size - write the `size' byte yaffs image starting\n"
" at offset `off' from memory address `addr'\n"
"nand erase [clean] [off size] - erase `size' bytes from\n"
" offset `off' (entire device if not specified)\n"
"nand bad - show bad blocks\n"
……………………
……………………
然后,在 nand 命令的处理函数 do_nand 中增加对"nand yaffs..."的支持。do_nand 函数仍在 commom/cmd_nand.c 中实现,代码修改如下:
……………………
……………………
opts.quiet = quiet;
ret = nand_write_opts(nand, &opts);
}
}
else if ( s != NULL && !strcmp(s, ".yaffs")){
if (read) {
nand_read_options_t opts;
memset(&opts, 0, sizeof(opts));
opts.buffer = (u_char*) addr;
opts.length = size;
opts.offset = off;
opts.readoob = 1;
opts.quiet = quiet;
ret = nand_read_opts(nand, &opts);
} else {
nand_write_options_t opts;
memset(&opts, 0, sizeof(opts));
opts.buffer = (u_char*) addr;
opts.length = size;
opts.offset = off;
opts.noecc = 1;
opts.writeoob = 1;
opts.blockalign = 1;
opts.quiet = quiet;
opts.skipfirstblk = 1;
ret = nand_write_opts(nand, &opts);
}
} else {
if (read)
ret = nand_read(nand, off, &size, (u_char *)addr);
else
ret = nand_write(nand, off, &size, (u_char *)addr);
}
…………………
…………………
2、在 include/nand.h 中进行如下修改,增加 skipfirstblk 成员:
struct nand_write_options {
u_char *buffer;
………………
………………
int pad;
int blockalign;
int skipfirstblk;
};
3、在 drivers/nand/nand_util.c 修改 nand_write_opts 函数,增加对 skipfirstblk 成员的支持:
int nand_write_opts(nand_info_t *meminfo, const nand_write_options_t *opts)
{
int imglen = 0;
………………
………………
int result;
int skipfirstblk = opts->skipfirstblk;
………………
………………
} while (offs < blockstart + erasesize_blockalign);
}
if (skipfirstblk) {
mtdoffset += erasesize_blockalign;
skipfirstblk = 0;
continue;
}
readlen = meminfo->oobblock;
………………
进行上面移植后,u-boot 已经支持 yaffs 文件系统映象的烧写,由于前面设置"opts.noecc=1" 不使用ECC校验码,烧写时会提示很多提示信息,可以修改 drivers/nand/nand_base.c 文件中的 nand_write_page 函数,将其注释掉。
case NAND_ECC_NONE:
//printk (KERN_WARNING "Writing data without ECC to NAND-FLASH is not recommended\n");
最后在u-boot顶层目录执行:make s3c2410_config
make
命令后,在u-boot顶层目录中生成u-boot.bin文件,用jtag线下到板子上reset正常启动。
友坚恒天已经正式推出了exynos4412开发板!四核A9哦~inand急速开机15S~