TQ2440 u-boot-2012.04.01移植二支持NAND启动
|
继?u-boot-2012.04.01移植一串口正常输出，继续修改代码支持单板NAND启动。最后直接用NOR Flash里的u-boot烧写自己移植的u-boot到NAND，方便电脑没有并口或手上没有openjtag,照样能移植u-boot，当然有openjtag更方便。
开发环境： 搭建开发环境详见ubuntu 10.04.4开发环境配置。 NOR Flash是内存接口，能直接运行程序，但是NAND Flash地址线都没有，是不能直接跑程序的。熟悉三星片子的人都知道s3c2440 NAND启动时，CPU会自动从NAND Flash读取前4KB到SRAM,同时把这段片内SRAM映射到nGCS0片选空间即0x0000 0000。而ARM架构的CPU第一条指令是从0地址开始执行的。相当于片内SRAM充当一个载体，把NAND前4KB映射到0地址，CPU开始执行NAND前4KB内容。 change@change:~$ cd Si/TQ2440/u-boot-2012.04.01/ 看到生成的u-boot.bin有360KB左右，这个放在NOR Flash里能直接启动，但是不利于NAND启动。u-boot运行后，不管是NNAD还是NOR Flash启动，都会进行重定位，即把代码拷到内存运行，就像PC机一样程序都是在内存运行的。那么支持NAND启动的u-boot，重定位之前代码必须小于4KB，才能跑起来。分析现在较新的u-boot源码(以后在另外文章分析)，代码连接时加-pie选项，重定位成位置无关代码，搞的很高级，不利于像S3C2440这样片内SRAM十分有限的SOC跑。这里修改重定位代码，支持NAND启动。 1.去掉-pie选项，不需要附加“*(.rel*)”、“*(.dynsm)”等信息 change@change:~/Si/TQ2440/u-boot-2012.04.01$ grep "-pie" * -nR 2.参考以前update写的start.S init.c修改代码 在arch/arm/cpu/arm920t/start.S112：增加 .globl base_sp 在arch/arm/cpu/arm920t/start.S:205行增加如下代码 ldr sp,=(CONFIG_SYS_INIT_SP_ADDR)/*sp =30000f80*/ bic sp,sp,#7 /* 8-byte alignment for ABI compliance */ bl nand_init_ll mov r0,#0 //ldr r1,=_start ldr r1,_TEXT_BASE //dr r2,=__bss_start //sub r2,r2,r1 ldr r2,_bss_start_ofs bl copy_code_to_sdram bl clear_bss ldr pc,=call_board_init_f arch/arm/cpu/arm920t/start.S221：注释掉下面2行 //ldr sp,=(CONFIG_SYS_INIT_SP_ADDR) 在arch/arm/cpu/arm920t/start.S:226行增加如下代码 /*unsigned int id */ 用自己的重定位代码，去掉u-boot自带的arch/arm/cpu/arm920t/start.S?231： /*------------------------------------------------------------------------------*/
/*
* 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
moveq r9,#0 /* no relocation. relocation offset(r9) = 0 */
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_SPL_BUILD
/*
* 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,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,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,LSR #4 /* r1 <- symbol index in .dynsym */
add r1,r1 /* r1 <- address of symbol in table */
ldr r1,[r1,#4] /* r1 <- symbol value */
add r1,r9 /* r1 <- relocated sym addr */
b fixnext
fixrel:
/* relative fix: increase location by offset */
ldr r1,[r0]
add r1,r9
fixnext:
str r1,[r0]
add r2,#8 /* each rel.dyn entry is 8 bytes */
cmp r2,r3
blo fixloop
#endif
clear_bss:
#ifndef CONFIG_SPL_BUILD
ldr r0,_bss_start_ofs
ldr r1,_bss_end_ofs
mov r4,r6 /* reloc addr */
add r0,r4
add r1,r4
mov r2,#0x00000000 /* clear */
clbss_l:cmp r0,r1 /* clear loop... */
bhs clbss_e /* if reached end of bss,exit */
str r2,[r0]
add r0,#4
b clbss_l
clbss_e:
bl coloured_LED_init
bl red_led_on
#endif以上代码全部去掉，在之前已重定位
接着在board/samsung/TQ2440/目录下增加init.c文件，board/samsung/TQ2440/init.c: /* NAND FLASH控制器 */
#define NFCONF (*((volatile unsigned long *)0x4E000000))
#define NFCONT (*((volatile unsigned long *)0x4E000004))
#define NFCMMD (*((volatile unsigned char *)0x4E000008))
#define NFADDR (*((volatile unsigned char *)0x4E00000C))
#define NFDATA (*((volatile unsigned char *)0x4E000010))
#define NFSTAT (*((volatile unsigned char *)0x4E000020))
/* GPIO */
#define GPHCON (*(volatile unsigned long *)0x56000070)
#define GPHUP (*(volatile unsigned long *)0x56000078)
/* UART registers*/
#define ULCON0 (*(volatile unsigned long *)0x50000000)
#define UCON0 (*(volatile unsigned long *)0x50000004)
#define UFCON0 (*(volatile unsigned long *)0x50000008)
#define UMCON0 (*(volatile unsigned long *)0x5000000c)
#define UTRSTAT0 (*(volatile unsigned long *)0x50000010)
#define UTXH0 (*(volatile unsigned char *)0x50000020)
#define URXH0 (*(volatile unsigned char *)0x50000024)
#define UBRDIV0 (*(volatile unsigned long *)0x50000028)
#define TXD0READY (1<<2)
void nand_read_ll(unsigned int addr,unsigned char *buf,unsigned int len);
static int isBootFromNorFlash(void)
{
volatile int *p = (volatile int *)0;
int val;
val = *p;
*p = 0x12345678;
if (*p == 0x12345678)
{
/* 写成功,是nand启动 */
*p = val;
return 0;
}
else
{
/* NOR不能像内存一样写 */
return 1;
}
}
void copy_code_to_sdram(unsigned char *src,unsigned char *dest,unsigned int len)
{
int i = 0;
/* 如果是NOR启动 */
if (isBootFromNorFlash())
{
while (i < len)
{
dest[i] = src[i];
i++;
}
}
else
{
//nand_init();
nand_read_ll((unsigned int)src,dest,len);
}
}
void clear_bss(void)
{
extern int __bss_start,__bss_end__;
int *p = &__bss_start;
for (; p < &__bss_end__; p++)
*p = 0;
}
void nand_init_ll(void)
{
#define TACLS 0
#define TWRPH0 1
#define TWRPH1 0
/* 设置时序 */
NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);
/* 使能NAND Flash控制器,初始化ECC,禁止片选 */
NFCONT = (1<<4)|(1<<1)|(1<<0);
}
static void nand_select(void)
{
NFCONT &= ~(1<<1);
}
static void nand_deselect(void)
{
NFCONT |= (1<<1);
}
static void nand_cmd(unsigned char cmd)
{
volatile int i;
NFCMMD = cmd;
for (i = 0; i < 10; i++);
}
static void nand_addr(unsigned int addr)
{
unsigned int col = addr % 2048;
unsigned int page = addr / 2048;
volatile int i;
NFADDR = col & 0xff;
for (i = 0; i < 10; i++);
NFADDR = (col >> 8) & 0xff;
for (i = 0; i < 10; i++);
NFADDR = page & 0xff;
for (i = 0; i < 10; i++);
NFADDR = (page >> 8) & 0xff;
for (i = 0; i < 10; i++);
NFADDR = (page >> 16) & 0xff;
for (i = 0; i < 10; i++);
}
static void nand_wait_ready(void)
{
while (!(NFSTAT & 1));
}
static unsigned char nand_data(void)
{
return NFDATA;
}
void nand_read_ll(unsigned int addr,unsigned int len)
{
int col = addr % 2048;
int i = 0;
/* 1. 选中 */
nand_select();
while (i < len)
{
/* 2. 发出读命令00h */
nand_cmd(0x00);
/* 3. 发出地址(分5步发出) */
nand_addr(addr);
/* 4. 发出读命令30h */
nand_cmd(0x30);
/* 5. 判断状态 */
nand_wait_ready();
/* 6. 读数据 */
for (; (col < 2048) && (i < len); col++)
{
buf[i] = nand_data();
i++;
addr++;
}
col = 0;
}
/* 7. 取消选中 */
nand_deselect();
}
同时修改该目录下的在Makfile,board/samsung/TQ2440/Makefile:
28:?COBJS:= TQ2440.o init.o? 其中lowlevel_init.S定义_TEXT_BASE: ? ??.word CONFIG_SYS_TEXT_BASE，是u-boot的重定位地址，搜索定义在TQ2440.h42: //#define CONFIG_SYS_TEXT_BASE 0x0 同时修改include/common.h 276： void?board_init_f? (ulong) __attribute__ ((noreturn)); 改为unsigned int?board_init_f? (ulong); arch/arm/lib/board.c265：增加extern ulong base_sp;//**add arch/arm/lib/board.c373：修改如下 //addr -= gd->mon_len; arch/arm/lib/board.c439：修改如下 base_sp = addr_sp;//**add 代码部分修改的差不多了，接下来还要修改链接脚本，确保重定位之前的代码编译在最前面 在arch/arm/cpu/u-boot.lds 38:增加如下 board/samsung/TQ2440/libTQ2440.o(.text) 3.重新配置、编译 change@change:~/Si/TQ2440/u-boot-2012.04.01$ make distclean ok编译通过，看看现在的u-boot.bin多大 change@change:~/Si/TQ2440/u-boot-2012.04.01$ ls u-boot.bin -l 4.烧写、测试 记住这里是烧到NAND，我用NOR Flash里的u-boot烧写，拨到NOR Flash启动，设置串口 115200 8 n 1
CPUID: 32440001 In:??? serial NAND erase: device 0 offset 0x0,size 0x80000 NAND write: device 0 offset 0x0,size 0x80000 单板断电，拨到NAND启动，上电串口输出： CPUID: 32440001 启动了，但卡在NOR Flash，NAND启动没检测到NOR Flash 就hang()这是正常的。这里修改一下不然它卡住，直接输出0 arch/arm/lib/board.c530：修改如下: ??puts("0 KBnr"); 修改后再次编译，应该就没问题了。发现还会卡在NET，暂时不支持网卡，先这样屏蔽arch/arm/lib/board.c:619//eth_initialize(gd->bd);同时将TQ2440.h131: #define CONFIG_SYS_PROMPT?"SMDK2410 # "改为#define CONFIG_SYS_PROMPT?"TQ2440 # " change@change:~/Si/TQ2440/u-boot-2012.04.01$ make distclean change@change:~/Si/TQ2440/u-boot-2012.04.01$ cp u-boot.bin /home/change/work/tftpboot/ OK编译通过，单板拨到NOR Flash启动，串口设置115200 8 n 1上电 U-Boot 2012.04.01 (Oct 25 2012 - 22:47:25) CPUID: 32440001 In:??? serial NAND erase: device 0 offset 0x0,size 0x80000 NAND write: device 0 offset 0x0,size 0x80000 烧写刚刚移植的u-boot.bin到NAND,现在单板断电，拨到NAND启动，串口115200 8 n 1上电
CPUID: 32440001 In:??? serial 这样NAND启动基本正常了，还需要完善，支持更多的功能。 （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |