X-003 FriendlyARM tiny4412 uboot移植之添加相应目录文件

时间:2023-03-09 05:14:05
X-003 FriendlyARM tiny4412 uboot移植之添加相应目录文件

X-003 FriendlyARM tiny4412 uboot移植之添加相应目录文件

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开发环境:win7 64位 + VMware12 + Ubuntu14.04 64位

工具链:linaro提供的gcc-linaro-6.1.1-2016.08-x86_64_arm-linux-gnueabi

要移植的u-boot版本:u-boot-2016-11

Tiny4412开发板硬件版本为

  底板:  Tiny4412/Super4412SDK 1506

    核心板:Tiny4412 - 1412

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 

在u-boot/board/samsung目录下基于exynos4412的开发板有:origen、odroid、trats、trats2,但是只有origen支持spl配置,根据exynos4412芯片启动的特点,选择origen作为参考比较合适。

一、参考origenu-boot中的代码结构添加tiny4412的目录和配置文件

1、添加tiny4412 板级目录

mkdir -p board/samsung/tiny4412

mkdir -p board/samsung/tiny4412/tools

2、添加tiny4412 配置文件

touch board/samsung/tiny4412/tiny4412.c

touch board/samsung/tiny4412/Kconfig

touch board/samsung/tiny4412/MAINTAINERS

touch board/samsung/tiny4412/Makefile

touch board/samsung/tiny4412/tools/mktiny4412spl.c

touch include/configs/tiny4412.h

touch configs/tiny4412_defconfig

touch arch/arm/dts/exynos4412-tiny4412.dts

3、修改、添加tiny4412 相关文件

3.1 添加board/samsung/tiny4412/tiny4412.c

diff --git a/board/samsung/tiny4412/tiny4412.c b/board/samsung/tiny4412/tiny4412.c

new file mode 100644

index 0000000..547dd45

--- /dev/null

+++ b/board/samsung/tiny4412/tiny4412.c

@@ -0,0 +1,40 @@

+/*

+ *         2016

+ * Author AP0904225 <ap0904225@qq.com>

+ *

+ *

+ * SPDX-License-Identifier:    GPL-2.0+

+ */

+

+#include <common.h>

+#include <asm/io.h>

+#include <asm/gpio.h>

+#include <asm/arch/cpu.h>

+#include <asm/arch/mmc.h>

+#include <asm/arch/periph.h>

+#include <asm/arch/pinmux.h>

+#include <usb.h>

+

+DECLARE_GLOBAL_DATA_PTR;

+

+u32 get_board_rev(void)

+{

+   return 0;

+}

+

+int exynos_init(void)

+{

+   return 0;

+}

+

+int board_usb_init(int index, enum usb_init_type init)

+{

+   return 0;

+}

+

+#ifdef CONFIG_BOARD_EARLY_INIT_F

+int exynos_early_init_f(void)

+{

+   return 0;

+}

+#endif

3.2 添加board/samsung/tiny4412/tools/mktiny4412spl.c

diff --git a/board/samsung/tiny4412/tools/mktiny4412spl.c b/board/samsung/tiny4412/tools/mktiny4412spl.c

new file mode 100644

index 0000000..c3a3e29

--- /dev/null

+++ b/board/samsung/tiny4412/tools/mktiny4412spl.c

@@ -0,0 +1,104 @@

+/*

+ *       2016

+ *  Author  AP0904225 <ap0904225@qq.com>

+ *

+ * SPDX-License-Identifier:    GPL-2.0+

+ */

+

+#include <stdio.h>

+#include <stdlib.h>

+#include <unistd.h>

+#include <fcntl.h>

+#include <errno.h>

+#include <string.h>

+#include <sys/stat.h>

+

+#define BUFSIZE            (16*1024)

+#define IMG_SIZE       ( (14*1024)- 4 )

+#define FILE_PERM      (S_IRUSR | S_IWUSR | S_IRGRP \

+               | S_IWGRP | S_IROTH | S_IWOTH)

+/*

+* Requirement:

+* IROM code reads first 14K bytes from boot device.

+* It then calculates the checksum of 14K-4 bytes and compare with data at

+* 14K-4 offset.

+*

+* This function takes two filenames:

+* IN  "u-boot-spl.bin" and

+* OUT "$(BOARD)-spl.bin as filenames.

+* It reads the "u-boot-spl.bin" in 16K buffer.

+* It calculates checksum of 14K-4 Bytes and stores at 14K-4 offset in buffer.

+* It writes the buffer to "$(BOARD)-spl.bin" file.

+*/

+

+int main(int argc, char **argv)

+{

+   int i, len;

+   unsigned char buffer[BUFSIZE] = {0};

+   int ifd, ofd;

+   unsigned int checksum = 0;

+   unsigned int count = 0;

+

+   if (argc != 3) {

+       printf(" %d Wrong number of arguments\n", argc);

+       exit(EXIT_FAILURE);

+   }

+

+   ifd = open(argv[1], O_RDONLY);

+   if (ifd < 0) {

+       fprintf(stderr, "%s: Can't open %s: %s\n",

+           argv[0], argv[1], strerror(errno));

+       exit(EXIT_FAILURE);

+   }

+

+   ofd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, FILE_PERM);

+   if (ofd < 0) {

+       fprintf(stderr, "%s: Can't open %s: %s\n",

+           argv[0], argv[2], strerror(errno));

+       if (ifd)

+           close(ifd);

+       exit(EXIT_FAILURE);

+   }

+

+   len = lseek(ifd, 0, SEEK_END);

+   lseek(ifd, 0, SEEK_SET);

+

+   count = (len < IMG_SIZE )? len : IMG_SIZE; //14K-4

+

+   if (read(ifd, buffer, count) != count) {

+       fprintf(stderr, "%s: Can't read %s: %s\n",

+           argv[0], argv[1], strerror(errno));

+

+       if (ifd)

+           close(ifd);

+       if (ofd)

+           close(ofd);

+

+       exit(EXIT_FAILURE);

+   }

+

+   for(i = 0;i < IMG_SIZE;i++)

+   {

+       checksum += (unsigned char)(buffer[i]);

+   }

+   *(unsigned int*)(buffer+i) = checksum;

+

+   if (write(ofd, buffer, BUFSIZE) != BUFSIZE) {

+       fprintf(stderr, "%s: Can't write %s: %s\n",

+           argv[0], argv[2], strerror(errno));

+

+       if (ifd)

+           close(ifd);

+       if (ofd)

+           close(ofd);

+

+       exit(EXIT_FAILURE);

+   }

+

+   if (ifd)

+       close(ifd);

+   if (ofd)

+       close(ofd);

+

+   return EXIT_SUCCESS;

+}

3.3 添加include/configs/tiny4412.h

diff --git a/include/configs/tiny4412.h b/include/configs/tiny4412.h

new file mode 100644

index 0000000..36af8b1

--- /dev/null

+++ b/include/configs/tiny4412.h

@@ -0,0 +1,115 @@

+/*

+ *         2016

+ *     Author AP0904225 <ap0904225@qq.com>

+ *

+ * Configuration settings for the FriendlyARM TINY4412 (EXYNOS4412) board.

+ *

+ * SPDX-License-Identifier:    GPL-2.0+

+ */

+

+#ifndef __CONFIG_TINY4412_H

+#define __CONFIG_TINY4412_H

+

+#include <configs/exynos4-common.h>

+

+/* TIZEN THOR downloader support */

+#undef CONFIG_CMD_THOR_DOWNLOAD

+#undef CONFIG_USB_FUNCTION_THOR

+

+/* High Level Configuration Options */

+#define TINY4412           1   /* working with TINY4412*/

+

+#define CONFIG_SYS_DCACHE_OFF      1

+

+/* TINY4412 has 4 bank of DRAM */

+#define CONFIG_NR_DRAM_BANKS       4

+#define CONFIG_SYS_SDRAM_BASE      0x40000000

+#define PHYS_SDRAM_1           CONFIG_SYS_SDRAM_BASE

+#define SDRAM_BANK_SIZE            (256 << 20) /* 256 MB */

+

+/* memtest works on */

+#define CONFIG_SYS_MEMTEST_START   CONFIG_SYS_SDRAM_BASE

+#define CONFIG_SYS_MEMTEST_END     (CONFIG_SYS_SDRAM_BASE + 0x6000000)

+#define CONFIG_SYS_LOAD_ADDR       (CONFIG_SYS_SDRAM_BASE + 0x3E00000)

+

+#define CONFIG_SYS_TEXT_BASE       0x43E00000

+

+#define CONFIG_MACH_TYPE       MACH_TYPE_TINY4412

+

+/* select serial console configuration */

+#define CONFIG_SERIAL2

+#define CONFIG_BAUDRATE            115200

+

+/* Console configuration */

+#define CONFIG_DEFAULT_CONSOLE     "console=ttySAC1,115200n8\0"

+

+#define CONFIG_SYS_MEM_TOP_HIDE    (1 << 20)   /* ram console */

+

+#define CONFIG_SYS_MONITOR_BASE    0x00000000

+

+/* Power Down Modes */

+#define S5P_CHECK_SLEEP            0x00000BAD

+#define S5P_CHECK_DIDLE            0xBAD00000

+#define S5P_CHECK_LPA          0xABAD0000

+

+#define CONFIG_SUPPORT_RAW_INITRD

+

+/* MMC SPL */

+#define COPY_BL2_FNPTR_ADDR    0x02020030

+#define CONFIG_SPL_TEXT_BASE   0x02023400

+#define CONFIG_SPL_STACK   0x02060000

+

+#define CONFIG_EXTRA_ENV_SETTINGS \

+   "loadaddr=0x40007000\0" \

+   "rdaddr=0x48000000\0" \

+   "kerneladdr=0x40007000\0" \

+   "ramdiskaddr=0x48000000\0" \

+   "console=ttySAC2,115200n8\0" \

+   "mmcdev=0\0" \

+   "bootenv=uEnv.txt\0" \

+   "loadbootenv=load mmc ${mmcdev} ${loadaddr} ${bootenv}\0" \

+   "importbootenv=echo Importing environment from mmc ...; " \

+       "env import -t $loadaddr $filesize\0" \

+        "loadbootscript=load mmc ${mmcdev} ${loadaddr} boot.scr\0" \

+        "bootscript=echo Running bootscript from mmc${mmcdev} ...; " \

+                "source ${loadaddr}\0"

+#define CONFIG_BOOTCOMMAND \

+   "if mmc rescan; then " \

+       "echo SD/MMC found on device ${mmcdev};" \

+       "if run loadbootenv; then " \

+           "echo Loaded environment from ${bootenv};" \

+           "run importbootenv;" \

+       "fi;" \

+       "if test -n $uenvcmd; then " \

+           "echo Running uenvcmd ...;" \

+           "run uenvcmd;" \

+       "fi;" \

+       "if run loadbootscript; then " \

+           "run bootscript; " \

+       "fi; " \

+   "fi;" \

+   "load mmc ${mmcdev} ${loadaddr} uImage; bootm ${loadaddr} "

+

+#define CONFIG_CLK_1000_400_200

+

+/* MIU (Memory Interleaving Unit) */

+#define CONFIG_MIU_2BIT_21_7_INTERLEAVED

+

+#define CONFIG_ENV_IS_IN_MMC

+#define CONFIG_SYS_MMC_ENV_DEV     0

+#define CONFIG_ENV_SIZE            (16 << 10)  /* 16 KB */

+#define RESERVE_BLOCK_SIZE     (512)

+#define BL1_SIZE           (16 << 10) /*16 K reserved for BL1*/

+#define CONFIG_ENV_OFFSET      (RESERVE_BLOCK_SIZE + BL1_SIZE)

+

+#define CONFIG_SPL_LDSCRIPT    "board/samsung/common/exynos-uboot-spl.lds"

+#define CONFIG_SPL_MAX_FOOTPRINT   (14 * 1024)

+

+#define CONFIG_SYS_INIT_SP_ADDR        0x02040000

+

+/* U-Boot copy size from boot Media to DRAM.*/

+#define COPY_BL2_SIZE      0x80000

+#define BL2_START_OFFSET   ((CONFIG_ENV_OFFSET + CONFIG_ENV_SIZE)/512)

+#define BL2_SIZE_BLOC_COUNT    (COPY_BL2_SIZE/512)

+

+#endif /* __CONFIG_H */

3.4 添加configs/tiny4412_defconfig

diff --git a/configs/tiny4412_defconfig b/configs/tiny4412_defconfig

new file mode 100644

index 0000000..93917b9

--- /dev/null

+++ b/configs/tiny4412_defconfig

@@ -0,0 +1,34 @@

+#

+# U-Boot 2016.11 Configuration for FriendlyARM tiny4412

+#

+CONFIG_ARM=y

+CONFIG_ARCH_EXYNOS=y

+CONFIG_ARCH_EXYNOS4=y

+CONFIG_TARGET_TINY4412=y

+CONFIG_IDENT_STRING=" for TINY4412"

+CONFIG_DEFAULT_DEVICE_TREE="exynos4412-tiny4412"

+CONFIG_SYS_CONSOLE_IS_IN_ENV=y

+CONFIG_SYS_CONSOLE_INFO_QUIET=y

+CONFIG_SPL=y

+CONFIG_HUSH_PARSER=y

+CONFIG_SYS_PROMPT="TINY4412 # "

+CONFIG_CMD_BOOTZ=y

+CONFIG_CMD_MMC=y

+CONFIG_CMD_MII=y

+CONFIG_CMD_CACHE=y

+CONFIG_CMD_EXT2=y

+CONFIG_CMD_EXT4=y

+CONFIG_CMD_EXT4_WRITE=y

+CONFIG_CMD_FAT=y

+CONFIG_CMD_FS_GENERIC=y

+CONFIG_OF_CONTROL=y

+

+#

+#NOTE:do not delete this:

+#

+# CONFIG_CMD_IMLS is not set

+# CONFIG_CMD_XIMG is not set

+# CONFIG_CMD_MISC is not set

+# CONFIG_CMD_FPGA is not set

+# CONFIG_CMD_NET is not set

+# CONFIG_CMD_NFS is not set

    3.5 添加board/samsung/tiny4412/MAINTAINERS

diff --git a/board/samsung/tiny4412/MAINTAINERS b/board/samsung/tiny4412/MAINTAINERS

new file mode 100644

index 0000000..ee5ad1a9

--- /dev/null

+++ b/board/samsung/tiny4412/MAINTAINERS

@@ -0,0 +1,6 @@

+TINY4412 BOARD

+M: AP0904225 <ap0904225@qq.com>

+S: Author  AP0904225

+F: board/samsung/tiny4412/

+F: include/configs/tiny4412.h

+F: configs/tiny4412_defconfig

3.6 修改 board/samsung/tiny4412/Kconfig

diff --git a/board/samsung/tiny4412/Kconfig b/board/samsung/tiny4412/Kconfig

new file mode 100644

index 0000000..954c391

--- /dev/null

+++ b/board/samsung/tiny4412/Kconfig

@@ -0,0 +1,15 @@

+if TARGET_TINY4412

+

+config SYS_BOARD

+   default "tiny4412"

+

+config SYS_VENDOR

+   default "samsung"

+

+config SYS_CONFIG_NAME

+   default "tiny4412"

+

+config EXYNOS4412

+   bool

+

+endif

3.7 修改board/samsung/tiny4412/Makefile

diff --git a/board/samsung/tiny4412/Makefile b/board/samsung/tiny4412/Makefile

new file mode 100644

index 0000000..55301d5

--- /dev/null

+++ b/board/samsung/tiny4412/Makefile

@@ -0,0 +1,23 @@

+#

+#       2016

+#  Author  AP0904225 <ap0904225@qq.com>

+#

+# SPDX-License-Identifier: GPL-2.0+

+#

+

+ifdef CONFIG_SPL_BUILD

+# necessary to create built-in.o

+obj- := __dummy__.o

+

+hostprogs-y := tools/mktiny4412spl

+always := $(hostprogs-y)

+

+# omit -O2 option to suppress

+#   warning: dereferencing type-punned pointer will break strict-aliasing rules

+#

+# TODO:

+# Fix the root cause in tools/mktiny4412spl.c and delete the following work-around

+$(obj)/tools/mktiny4412spl: HOSTCFLAGS:=$(filter-out -O2,$(HOSTCFLAGS))

+else

+obj-y  += tiny4412.o

+endif

3.8 修改arch/arm/mach-exynos/Kconfig,在执行make menuconfig时会看到tiny4412 board选项

diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig

index ce2a16f..c8bb811 100644

--- a/arch/arm/mach-exynos/Kconfig

+++ b/arch/arm/mach-exynos/Kconfig

@@ -56,6 +56,15 @@ config TARGET_TRATS2

config TARGET_ODROID

bool "Exynos4412 Odroid board"

+config TARGET_TINY4412

+   bool "Exynos4412 FriendlyARM Tiny4412 board"

+   select SUPPORT_SPL

+   select SPL

+   select EXYNOS4412

+       help

+       Support FriendlyARM Tiny4412 board based on Samsung exynos4412

+       CPU: S5PC220[Samsung SOC on SMP Platform Base on ARM CortexA9].

+

endchoice

endif

@@ -145,6 +154,7 @@ source "board/samsung/universal_c210/Kconfig"

source "board/samsung/origen/Kconfig"

source "board/samsung/trats2/Kconfig"

source "board/samsung/odroid/Kconfig"

+source "board/samsung/tiny4412/Kconfig"

source "board/samsung/arndale/Kconfig"

source "board/samsung/smdk5250/Kconfig"

source "board/samsung/smdk5420/Kconfig"

3.9 修改 arch/arm/mach-exynos/Makefile

diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile

index 0cc6c32..ac47ab2 100644

--- a/arch/arm/mach-exynos/Makefile

+++ b/arch/arm/mach-exynos/Makefile

@@ -15,6 +15,7 @@ ifdef CONFIG_SPL_BUILD

obj-$(CONFIG_EXYNOS5)  += clock_init_exynos5.o

obj-$(CONFIG_EXYNOS5)  += dmc_common.o dmc_init_ddr3.o

obj-$(CONFIG_EXYNOS4210)+= dmc_init_exynos4.o clock_init_exynos4.o

+obj-$(CONFIG_EXYNOS4412)+= dmc_init_exynos4.o clock_init_exynos4.o

obj-y  += spl_boot.o tzpc.o

obj-y  += lowlevel_init.o

endif

3.10 修改arch/arm/mach-exynos/exynos4_setup.h

diff --git a/arch/arm/mach-exynos/exynos4_setup.h b/arch/arm/mach-exynos/exynos4_setup.h

index 9f29d94..838e02c 100644

--- a/arch/arm/mach-exynos/exynos4_setup.h

+++ b/arch/arm/mach-exynos/exynos4_setup.h

@@ -440,6 +440,12 @@ struct mem_timings {

#define APB_SFR_ARBRITATION_CONF_VAL   0x00000001

#endif

+#ifdef TINY4412

+/* Interleave: 2Bit, Interleave_bit1: 0x15, Interleave_bit0: 0x7 */

+#define APB_SFR_INTERLEAVE_CONF_VAL    0x20001507

+#define APB_SFR_ARBRITATION_CONF_VAL   0x00000001

+#endif

+

#define INTERLEAVE_ADDR_MAP_START_ADDR 0x40000000

#define INTERLEAVE_ADDR_MAP_END_ADDR   0xbfffffff

#define INTERLEAVE_ADDR_MAP_EN     0x00000001

3.11、修改arch/arm/include/asm/mach-types.h,增加tiny4412machine ID

diff --git a/arch/arm/include/asm/mach-types.h b/arch/arm/include/asm/mach-types.h

index d51be0b..297f1c3 100644

--- a/arch/arm/include/asm/mach-types.h

+++ b/arch/arm/include/asm/mach-types.h

@@ -1107,6 +1107,7 @@ extern unsigned int __machine_arch_type;

#define MACH_TYPE_COLIBRI_T30          4493

#define MACH_TYPE_APALIS_T30           4513

#define MACH_TYPE_OMAPL138_LCDK        2495

+#define MACH_TYPE_TINY4412             4608

#ifdef CONFIG_ARCH_EBSA110

# ifdef machine_arch_type

3.12、修改arch/arm/dts/Makefile,用于编译tiny4412设备树

diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile

index 836a8c4..a654d74 100644

--- a/arch/arm/dts/Makefile

+++ b/arch/arm/dts/Makefile

@@ -14,6 +14,7 @@ dtb-$(CONFIG_EXYNOS4) += exynos4210-origen.dtb \

exynos4210-universal_c210.dtb \

exynos4210-trats.dtb \

exynos4412-trats2.dtb \

+   exynos4412-tiny4412.dtb \

exynos4412-odroid.dtb

dtb-$(CONFIG_TARGET_HIKEY) += hi6220-hikey.dtb

3.13 添加arch/arm/dts/exynos4412-tiny4412.dts,使用uart0作为终端

diff --git a/arch/arm/dts/exynos4412-tiny4412.dts b/arch/arm/dts/exynos4412-tiny4412.dts

new file mode 100644

index 0000000..8822d52

--- /dev/null

+++ b/arch/arm/dts/exynos4412-tiny4412.dts

@@ -0,0 +1,86 @@

+/*

+ * FriendlyARM Tiny4412 board device tree source

+ *

+ *             2016

+ *  Author  AP0904225 <ap0904225@qq.com>

+ *

+ * SPDX-License-Identifier:    GPL-2.0+

+ */

+

+/dts-v1/;

+#include "exynos4412.dtsi"

+

+/ {

+   model = "Tiny4412 based on Exynos4412";

+   compatible = "samsung,tiny4412", "samsung,exynos4412";

+

+   aliases {

+       i2c0 = "/i2c@13860000";

+       i2c1 = "/i2c@13870000";

+       i2c2 = "/i2c@13880000";

+       i2c3 = "/i2c@13890000";

+       i2c4 = "/i2c@138a0000";

+       i2c5 = "/i2c@138b0000";

+       i2c6 = "/i2c@138c0000";

+       i2c7 = "/i2c@138d0000";

+       serial0 = "/serial@13800000";

+       console = "/serial@13810000";

+       mmc2 = "/sdhci@12530000";

+       mmc4 = "/dwmmc@12550000";

+   };

+

+   i2c@13860000 {

+       samsung,i2c-sda-delay = <100>;

+       samsung,i2c-slave-addr = <0x10>;

+       samsung,i2c-max-bus-freq = <100000>;

+       status = "okay";

+   };

+

+   serial@13810000 {

+       status = "okay";

+   };

+

+   sdhci@12510000 {

+       status = "disabled";

+   };

+

+   sdhci@12520000 {

+       status = "disabled";

+   };

+

+   sdhci@12530000 {

+       samsung,bus-width = <4>;

+       samsung,timing = <1 2 3>;

+       cd-gpios = <&gpk2 2 0>;

+   };

+

+   sdhci@12540000 {

+       status = "disabled";

+   };

+

+   dwmmc@12550000 {

+       samsung,bus-width = <8>;

+       samsung,timing = <2 1 0>;

+       samsung,removable = <0>;

+       fifoth_val = <0x203f0040>;

+       bus_hz = <400000000>;

+       div = <0x3>;

+       index = <4>;

+   };

+

+   ehci@12580000 {

+       compatible = "samsung,exynos-ehci";

+       reg = <0x12580000 0x100>;

+       #address-cells = <1>;

+       #size-cells = <1>;

+       phy {

+           compatible = "samsung,exynos-usb-phy";

+           reg = <0x125B0000 0x100>;

+       };

+   };

+

+   emmc-reset {

+       compatible = "samsung,emmc-reset";

+       reset-gpio = <&gpk1 2 0>;

+   };

+};

添加完相关代码目录后,执行如下命令进行编译uboot:

 

$ make distclean

$ make tiny4412_defconfig

$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-

添加的文件没有出错的话,可以顺利编译出u-boot-spl.bin 和u-boot.bin文件,此时这个u-boot-spl.bin 和u-boot.bin文件还不能直接用在tiny4412 SDK开发板上,需进一步修改代码。

到这里第一阶段的添加相关代码目录文件的工作就告一段落了。

参考

1、友善之臂tiny4412 uboot_tiny4412-20130729.tar.gz

2、http://www.wowotech.net/x_project/bubblegum_uboot_porting.html

3、http://www.wowotech.net/u-boot/boot_flow_1.html

4、http://www.wowotech.net/u-boot/boot_flow_2.html

5、http://www.cnblogs.com/pengdonglin137/p/5080645.html