silenceran |
2009-01-10 13:17 |
u-boot移植(将分(一)、(二)、(三)(四)部分完成移植工作) (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 #include #define BWSCON 0x48000000 #define DW8 (0x0) #define DW16 (0x1) #define DW32 (0x2) #define WAIT (0x1 (0x1#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 #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 int i, j; if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) { return -1; } NFCONF &= ~0x800; for(i=0; i for(i=start_addr; i NFCMD = 0; NFADDR = i & 0xff; NFADDR = (i >> 9) & 0xff; NFADDR = (i >> 17) & 0xff; NFADDR = (i >> 25) & 0xff; wait_idle(); for(j=0; j } } 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
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