u-boot 2013.04-rc1移植（3）

SD卡启动

s3c6410支持SD卡启动原理，参考《S3C6410-Internal-ROM-Booting.pdf》一文。

其原理为，IC内部已经固化了一段代码，上电后如果Boot管脚选择了SD卡启动方式，将会自动从SD卡固定的地址加载8K的代码到SRAM中（s3c6410内部8K SRAM）运行，运行之后需要将剩下的全部u-boot代码加搬运到ram中。

而现在要做的关键是，怎样搬运代码到ram。

1、建立s3c6410_sdboot.c，/home/eric/Documents/u-boot-2013.04-rc1/arch/arm/cpu/arm1176/s3c64xx/s3c6410_sdboot.c

/*
*  Samsung S3C6410 SD/MMC Device Boot
*      date: 2016/11/05
*  Licensed under the GPL-2 or later.
*/

#include <common.h>
#include <asm/io.h>
#ifdef  CONFIG_MMC_CHANNEL
#define MMC_CHANNEL CONFIG_MMC_CHANNEL
#else
#define MMC_CHANNEL 0
#endif

#define ELFIN_HSMMC_BASE    (0x7C200000 + MMC_CHANNEL*0x100000)
#define HM_CONTROL4 (ELFIN_HSMMC_BASE+0x8C)
#define globalBlockSizeHide *((volatile unsigned int*)(0x0C004000-0x4))
#define globalSDHCInfo      *((volatile unsigned int*)(0x0C004000-0x8))

#define LAST_BLKPOS (globalBlockSizeHide - 2)
#define BLK_SIZE 512
#define BL1_SIZE (1024*8)
#define BL2_SIZE (300*1024)

#if 0
#define ENV_SIZE CONFIG_ENV_SIZE
#else
#define ENV_SIZE (16*1024)
#endif

#define BL1_BLKCNT   (BL1_SIZE/BLK_SIZE)
#define BL2_BLKCNT   (BL2_SIZE/BLK_SIZE)
#define ENV_BLKCNT   (ENV_SIZE/BLK_SIZE)
#define STARTBLKADDR (LAST_BLKPOS - BL1_BLKCNT - BL2_BLKCNT - ENV_BLKCNT)
#define DESTADDR     CONFIG_SYS_PHY_UBOOT_BASE

//此函数在IROM中固化的代码已经实现，只开放了固定的地址用来调用。
#define CopyMMCtoMem(a,b,c,d,e) (((int(*)(int, uint, ushort, uint *, int)) \
(*((uint *)(0x0C004000 + 0x8))))(a,b,c,d,e))

int BootCopyMMCtoMem()
{
writel(readl(HM_CONTROL4) | (0x3 << 16), HM_CONTROL4);
return  CopyMMCtoMem(0, STARTBLKADDR, BL2_BLKCNT, (uint *)DESTADDR, 0);
}

思考？因为SD卡和SDHC卡，IROM加载的起始地址并不相同，相差1024Block。但此处，不论SD卡类型是SD还是SDHC，copyMMCtoMem函数的参数都是固定跳过2个block！

#define LAST_BLKPOS (globalBlockSizeHide - 2)

解密：因为IROM中得到Block总数，如果是SDHC则自动减去1024。其目大概是保证SD卡和SDHC的兼容性吧！

2、修改配置文件/home/eric/Documents/u-boot-2013.04-rc1/include/configs/smdk6410.h

260行添加：CONFIG_BOOT_SD宏

#define CONFIG_BOOT_SD

3、修改u-boot-2013.04-rc1/arch/arm/cpu/arm1176/s3c64xx/Makefile

36行添加：将s3c6410_sdboot.c编译到u-boot中

COBJS-$(CONFIG_BOOT_SD)    += s3c6410_sdboot.o     ##eric++ 2017-11-04

4、 修改/home/eric/Documents/u-boot-2013.04-rc1/board/samsung/smdk6410/lowlevel_init.s

54行修改：修改IO配置，对应板子上的LED

/* LED on only #8 */
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x00001111//0x55540000         //eric++2017-11-04
str r1, [r0, #GPMCON_OFFSET]//str   r1, [r0, #GPNCON_OFFSET]

ldr r1, =0x000000AA//ldr    r1, =0x55555555
str r1, [r0, <
abb1
span class="hljs-preprocessor">#GPMPUD_OFFSET]//str   r1, [r0, #GPNPUD_OFFSET]

ldr r1, =0x000A//ldr    r1, =0xf000
str r1, [r0, #GPMDAT_OFFSET]//str   r1, [r0, #GPNDAT_OFFSET]

134行修改：上电后的状态

/* LED test */
ldr r0, =ELFIN_GPIO_BASE
ldr r1, =0x000000AA//0x3000         //eric++
str r1, [r0, #GPMDAT_OFFSET]//str   r1, [r0, #GPNDAT_OFFSET]

225行修改时钟，6400和6410时钟配置不同，否则将不能正常启动u-boot

/* FOUT of EPLL is 96MHz */
ldr r1, =0x80200203//0x200203           //eric++

5、修改u-boot-2013.04-rc1/arch/arm/cpu/arm1176/start.s,添加SD跳转

226行添加：完成初始化后，调用BootCopyMMCtoMem，将u-boot加载到ram中运行。

/*  eric++ 2017-11-04*/
#if defined(CONFIG_BOOT_SD) && !defined(CONFIG_NAND_SPL)
ldr sp, =CONFIG_SYS_INIT_SP_ADDR
bl  BootCopyMMCtoMem
cmp r0, #0
copyerror:
beq copyerror
ldr pc, =_main
#endif
/* end add */

6、修改基本完成。尝试进行编译，可以成功生成u-boot.bin

eric@eric-PC:~/Documents/u-boot-2013.04-rc1$ ls
api         disk       lib          README           u-boot.bin
arch        doc        MAINTAINERS  rules.mk         u-boot.lds
board       drivers    MAKEALL      snapshot.commit  u-boot.map
boards.cfg  dts        Makefile     spl              u-boot-nand.bin
common      examples   mkconfig     System.map       u-boot.srec
config.mk   fs         nand_spl     test
COPYING     helper.mk  net          tools
CREDITS     include    post         u-boot
eric@eric-PC:~/Documents/u-boot-2013.04-rc1$

7、将生成的u-boot，通过烧录软件烧录至SD卡中(借用lq的软件)



其中SD和SDHC中u-boot.bin分布如下：



8、开发板，插入SD卡，接入串口线，启动超级终端(或者dnw)，默认波特率为115200。BOOT拨至SD卡启动。上电！（心情无比激动）

但是遗憾！串口没有任何信息，表明板子并没有成功启动，但是LED好像亮了！

无法启动，修改如下：

/home/eric/Documents/u-boot-2013.04-rc1/board/samsung/smdk6410/u-boot-nand.lds

38行添加：保证此部分代码，在u-boot.bin的前8K代码中

board/samsung/smdk6410/libsmdk6410.o    (.text)

9、再次编译，烧录，启动

U-Boot 2013.04-rc1 (Nov 04 2017 - 16:41:04) for SMDK6410

CPU:     S3C6410@533MHz

Fclk = 533MHz, Hclk = 133MHz, Pclk = 66MHz (ASYNC Mode)

Board:   SMDK6410

DRAM:  128 MiB

WARNING: Caches not enabled

Flash: *** failed ***

### ERROR ### Please RESET the board ###

至此！虽然出现了错误信息，但可以成功启动！！！

10、修改/home/eric/Documents/u-boot-2013.04-rc1/arch/arm/lib/board.c

588行：flash 容量0，忽略，并继续运行

//hang(); //eric++2017-11-04

11、重新启动

U-Boot 2013.04-rc1 (Nov 04 2017 - 17:13:33) for SMDK6410

CPU:     S3C6410@533MHz

Fclk = 533MHz, Hclk = 133MHz, Pclk = 66MHz (ASYNC Mode)

Board:   SMDK6410

DRAM:  128 MiB

WARNING: Caches not enabled

Flash: *** failed ***

NAND:  raise: Signal # 8 caught

raise: Signal # 8 caught

raise: Signal # 8 caught

raise: Signal # 8 caught

一直不断输出raise: Signal # 8 caught。其根本原因是程序中出现了运算错误，导致。

修复：u-boot-2013.04-rc1/arch/arm/cpu/arm1176/s3c64xx/timer.c

46行：将timer_load_val ，lastdec，timestamp分别用gd->arch中的timer_rate_hz，lastinc，timer_reset_value代替。并声明gd。

#define timer_load_val  gd->arch.timer_rate_hz//static ulong timer_load_val;        //eric++ 2017-11-04
DECLARE_GLOBAL_DATA_PTR     //eric++,声明gd

63行：

/* Internal tick units */
/* Last decremneter snapshot */
#define lastdec gd->arch.lastinc//static unsigned long lastdec;     //eric++ 2017-11-04
/* Monotonic incrementing timer */
#define timestamp   gd->arch.timer_reset_value//static unsigned long long timestamp;    //eric++ 2017-11-04

11、重新启动

U-Boot 2013.04-rc1 (Nov 04 2017 - 21:48:46) for SMDK6410

CPU:     S3C6410@533MHz

Fclk = 533MHz, Hclk = 133MHz, Pclk = 66MHz (ASYNC Mode)

Board:   SMDK6410

DRAM:  128 MiB

WARNING: Caches not enabled

Flash: *** failed ***

NAND:  nand_get_flash_type: second ID read did not match 00,04 against 00,00

No NAND device found!!!

0 MiB

*** Warning - bad CRC, using default environment

In:    serial

Out:   serial

Err:   serial

Net:   CS8900-0

Hit any key to stop autoboot:  0

no devices available

Wrong Image Format for bootm command

ERROR: can't get kernel image!

SMDK6410 #

至此，u-boot，启动初步完成。