레이블이 Uboot-Script인 게시물을 표시합니다. 모든 게시물 표시
레이블이 Uboot-Script인 게시물을 표시합니다. 모든 게시물 표시

3/29/2020

Uboot 설정 과 Device Tree 처리방법

1. Uboot 구성 및 설정 

Uboot 기본 Manual
  https://www.denx.de/wiki/DULG/Manual

Uboot 의 전체 구성 과 설정방법
  https://gitlab.denx.de/u-boot/u-boot/raw/HEAD/README


  • Uboot 의 명령어
  https://www.denx.de/wiki/view/U-Bootdoc/BasicCommandSet
  https://www.digi.com/resources/documentation/digidocs/PDFs/90000852.pdf
  https://sites.google.com/site/manisbutareed/bringing-my-beagles-to-heel/u-boot-commands
  https://sites.google.com/site/manisbutareed/bringing-my-beagles-to-heel/selected-annotated-u-boot-commands


  • Uboot 환경값
  https://sites.google.com/site/manisbutareed/bringing-my-beagles-to-heel/u-boot-environment-variables


1.1 Uboot 와 DTB 결합구성 


  • Uboot Image 의 구성
  1. Uboot의 DTS를 DTC를 이용하여 DTB 파일생성 
  2. Uboot  Build를 진행 Uboot 파일생성
  3. cat를 이용하여 상위 두개 파일을 하나로 결합 
  4. mkimage를 이용하여 최종 Image 생성 

DTB Image를 최종 합쳐서 Uboot Image로 만들어서 제공

https://rocketboards.org/foswiki/Documentation/A10GSRDV1511GeneratingUBootAndUBootDeviceTree

  • Uboot Build 된곳에서 기본적인확인 
상위 그림처럼 Uboot 와 Uboot의 DTB를 결합하여 최종 Uboot 생성

$ cat dts/.dt.dtb.cmd  //Uboot DTB 파일 
cmd_dts/dt.dtb := cat arch/arm/dts/imx6sx-sdb-emmc.dtb > dts/dt.dtb

$ cat .u-boot-nodtb.bin.cmd  // 일반 Uboot bin 생성 (objcopy)
cmd_u-boot-nodtb.bin := arm-poky-linux-gnueabi-objcopy --gap-fill=0xff  -j .text -j .secure_text -j .secure_data -j .rodata -j .hash -j .data -j .got -j .got.plt -j .u_boot_list -j .rel.dyn -j .binman_sym_table -j .text_rest -j .dtb.init.rodata -j .efi_runtime -j .efi_runtime_rel -O binary   u-boot u-boot-nodtb.bin

$ cat .u-boot-dtb.bin.cmd    //Uboot 와 DTB 결합 
cmd_u-boot-dtb.bin := cat u-boot-nodtb.bin dts/dt.dtb > u-boot-dtb.bin

$ cat .u-boot.bin.cmd      // Uboot 이름변경 및 최종 uboot
cmd_u-boot.bin := cp u-boot-dtb.bin u-boot.bin   

$ cat .u-boot.imx.cmd // 최종 u-boot image
cmd_u-boot.imx := ./tools/mkimage -n u-boot.cfgout -T imximage -e 0x87800000 -d u-boot.bin u-boot.imx >u-boot.imx.log  && cat u-boot.imx.log

Uboot 와 Kernel 는 각각 DTS 존재하며, 두 DTS가 동일하지만, Uboot의 DTB 와 Kernel DTB는 각각 별도로 사용이 되어지고 있다.

내 개인적인 생각으로는 1st Boot Loader가 Uboot에게 전달하고, Uboot가 다시 Kernel에게 전달하여 전부 공유할 것이라고 생각했는데,
설정을 바꿔서 어떻게 공유할 수 있는지를 알아봐야겠다.
(환경변수 fdtcontroladdr 와  fdt_addr를 동일하게 공유)

Device Tree Boot 기본 구조
아래링크의 그림부분 참조
  https://ahyuo79.blogspot.com/2015/08/am437x-kernel-device-tree.html

TI-Sitara 의 Uboot / Kernel 의 Device Tree 관련부분 복습
  https://ahyuo79.blogspot.com/2015/08/kernel-boot-kernel-device-tree.html
  https://elinux.org/Device_Tree_Reference

Uboot 관련정보정리
  https://www.denx.de/wiki/pub/U-Boot/MiniSummitELCE2014/uboot2014_kconfig.pdf

1.2 Uboot 와 DTB 관련소스분석 

  • Uboot fdt 확인
=> version
U-Boot 2019.04-4.19.35-1.1.0+g4d37753 (May 13 2020 - 07:43:31 +0000)

arm-poky-linux-gnueabi-gcc (GCC) 8.3.0
GNU ld (GNU Binutils) 2.32.0.20190204

=> bdinfo
arch_number = 0x00000000
boot_params = 0x80000100
DRAM bank   = 0x00000000
-> start    = 0x80000000
-> size     = 0x40000000
baudrate    = 115200 bps
TLB addr    = 0xbfff0000
relocaddr   = 0xbff45000
reloc off   = 0x38745000
irq_sp      = 0xbdf359f0
sp start    = 0xbdf359e0
FB base     = 0x00000000
Early malloc usage: fc / 400
fdt_blob    = 0xbdf35a08  //uboot용 dtb (device tree blob) 주소

  • Uboot Config 설정확인 
$ vi .config   // Uboot Config 
....
#
# Partition Types
#
CONFIG_PARTITIONS=y
# CONFIG_MAC_PARTITION is not set
CONFIG_DOS_PARTITION=y
# CONFIG_ISO_PARTITION is not set
# CONFIG_AMIGA_PARTITION is not set
CONFIG_EFI_PARTITION=y
CONFIG_EFI_PARTITION_ENTRIES_NUMBERS=128
CONFIG_EFI_PARTITION_ENTRIES_OFF=0
CONFIG_PARTITION_UUIDS=y
# CONFIG_PARTITION_TYPE_GUID is not set
CONFIG_SUPPORT_OF_CONTROL=y
CONFIG_DTC=y

#
# Device Tree Control
#
## 아래 설정으로 Uboot에서 Device Tree 사용 (fdt 사용가능)
CONFIG_OF_CONTROL=y          
# CONFIG_OF_BOARD_FIXUP is not set
# CONFIG_OF_LIVE is not set
## 아래 설정때문에 cat u-boot.bin u-boot.dtb >image.bin 결합 
CONFIG_OF_SEPARATE=y
# CONFIG_OF_EMBED is not set
# CONFIG_OF_BOARD is not set
# CONFIG_OF_PRIOR_STAGE is not set
CONFIG_DEFAULT_DEVICE_TREE="imx6sx-sdb-emmc"
# CONFIG_MULTI_DTB_FIT is not set
CONFIG_MKIMAGE_DTC_PATH="dtc"

#
# Environment
#
# CONFIG_ENV_DEFAULT_NOWHERE is not set
# CONFIG_ENV_IS_IN_EEPROM is not set
# CONFIG_ENV_IS_IN_FAT is not set
# CONFIG_ENV_IS_IN_EXT4 is not set
# CONFIG_ENV_IS_IN_FLASH is not set
CONFIG_ENV_IS_IN_MMC=y
.....


  • Uboot Linker Script 
$ vi arch/arm/cpu/u-boot.lds  

        .rel_dyn_end :
        {
                *(.__rel_dyn_end)
        }

        .end :
        {
                *(.__end)
        }

        _image_binary_end = .;

//binary 로 변경시 아래부분은 필요없음 

        /*
         * Deprecated: this MMU section is used by pxa at present but
         * should not be used by new boards/CPUs.
         */
        . = ALIGN(4096);
        .mmutable : {
                *(.mmutable)
        }
.....
$ vi u-boot.map // System.map 재확인 

  • Uboot Source 확인
Uboot Config 기반으로 소스확인

$ vi common/board_r.c
......
static init_fnc_t init_sequence_r[] = {
        initr_trace,
        initr_reloc,
...
#ifdef CONFIG_MMC
        initr_mmc,
#endif
        initr_env,
....
        run_main_loop,
};

static int initr_env(void)
{
        /* initialize environment */
        if (should_load_env())
                env_relocate();
        else
                set_default_env(NULL, 0);
// 매번 Booting 때마다 fdtcontroladdr 변수설정하기 때문에 User가 변경해도 소용없음 
// Uboot에서 printenv로 확인가능하며 상위 CONFIG확인 
#ifdef CONFIG_OF_CONTROL
        env_set_hex("fdtcontroladdr",
                    (unsigned long)map_to_sysmem(gd->fdt_blob));  
#endif

        /* Initialize from environment */
        load_addr = env_get_ulong("loadaddr", 16, load_addr);

        return 0;
}

상위 설정대로 했을 경우 아래 bold 체가 실행

$ vi lib/fdtdec.c  // Uboot의 dtb부분 처리를 이해가능 

#if defined(CONFIG_OF_BOARD) || defined(CONFIG_OF_SEPARATE)
/*
 * For CONFIG_OF_SEPARATE, the board may optionally implement this to
 * provide and/or fixup the fdt.
 */
__weak void *board_fdt_blob_setup(void)
{
        void *fdt_blob = NULL;
#ifdef CONFIG_SPL_BUILD
        /* FDT is at end of BSS unless it is in a different memory region */
        if (IS_ENABLED(CONFIG_SPL_SEPARATE_BSS))
                fdt_blob = (ulong *)&_image_binary_end;
        else
                fdt_blob = (ulong *)&__bss_end;
#else
        //CONFIG_OF_SEPARATE만 사용해서 uboot 끝에서 fdt를 가져옴 (Linker Script 참조)
        /* FDT is at end of image */
        fdt_blob = (ulong *)&_end;     
#endif
        return fdt_blob;
}
#endif

int fdtdec_setup(void)
{
#if CONFIG_IS_ENABLED(OF_CONTROL)   // 현재설정 CONFIG_OF_CONTROL=y

# if CONFIG_IS_ENABLED(MULTI_DTB_FIT) // 현재 미설정 # CONFIG_MULTI_DTB_FIT is not set
        void *fdt_blob;
# endif

# ifdef CONFIG_OF_EMBED  // 현재 미설정 # CONFIG_OF_EMBED is not set
        /* Get a pointer to the FDT */
#  ifdef CONFIG_SPL_BUILD // 현재 미설정 
        gd->fdt_blob = __dtb_dt_spl_begin;
#  else
        gd->fdt_blob = __dtb_dt_begin;
#  endif
# elif defined(CONFIG_OF_BOARD) || defined(CONFIG_OF_SEPARATE) // 현재 이부분만 실행 
        /* Allow the board to override the fdt address. */
        gd->fdt_blob = board_fdt_blob_setup();  // 상위함수 참고 CONFIG_OF_BOARD는 미설정
# elif defined(CONFIG_OF_HOSTFILE)
        if (sandbox_read_fdt_from_file()) {
                puts("Failed to read control FDT\n");
                return -1;
        }
# endif
# ifndef CONFIG_SPL_BUILD  // 현재 미설정 
        /* Allow the early environment to override the fdt address */
#  if CONFIG_IS_ENABLED(OF_PRIOR_STAGE)   // 현재 미설정 # CONFIG_OF_PRIOR_STAGE is not set
        gd->fdt_blob = (void *)prior_stage_fdt_address;
#  else
// 상위에서 설정된 gd->fdt_blob 변수 fdtcontroladdr의 기본값으로 읽어옴 
//bdinfo 와 printenv 확인가능 
        gd->fdt_blob = map_sysmem
                (env_get_ulong("fdtcontroladdr", 16,
                               (unsigned long)map_to_sysmem(gd->fdt_blob)), 0); 
#  endif
# endif

# if CONFIG_IS_ENABLED(MULTI_DTB_FIT)   // 현재미설정 # CONFIG_MULTI_DTB_FIT is not set
        /*
         * Try and uncompress the blob.
         * Unfortunately there is no way to know how big the input blob really
         * is. So let us set the maximum input size arbitrarily high. 16MB
         * ought to be more than enough for packed DTBs.
         */
        if (uncompress_blob(gd->fdt_blob, 0x1000000, &fdt_blob) == 0)
                gd->fdt_blob = fdt_blob;

        /*
         * Check if blob is a FIT images containings DTBs.
         * If so, pick the most relevant
         */
        fdt_blob = locate_dtb_in_fit(gd->fdt_blob);
        if (fdt_blob) {
                gd->multi_dtb_fit = gd->fdt_blob;
                gd->fdt_blob = fdt_blob;
        }

# endif
#endif

        return fdtdec_prepare_fdt();
}

이전의 Uboot 관련소스
  https://lists.denx.de/pipermail/u-boot/2012-July/127516.html
  https://gitlab.labs.nic.cz/turris/u-boot-turris/commit/eea63e05d0b7f54e7aa39725015483972c71cb3c

  • Uboot의 DTB  설정확인
$ vi arch/arm/dts/Makefile
....
dtb-$(CONFIG_MX6SX) += \
        imx6sx-14x14-arm2.dtb \
        imx6sx-17x17-arm2.dtb \
        imx6sx-17x17-arm2-ecspi.dtb \
        imx6sx-17x17-arm2-gpmi-weim.dtb \
        imx6sx-19x19-arm2.dtb \
        imx6sx-19x19-arm2-ecspi.dtb \
        imx6sx-19x19-arm2-gpmi-weim.dtb \
        imx6sx-sabreauto.dtb \
        imx6sx-sdb.dtb \
        imx6sx-sdb-emmc.dtb
.....


1.3 Uboot 의 Flattened Device Tree (FDT)

Uboot는 DTB File을 Memory 에 Load하여 기본 확인가능하며, 이를 수정도 가능한 명령이 fdt 명령어이다.
uImage 에서 사용하게 될 dtb, 즉 kernel 용 dtb를 fdt 명령어를 이용하여 이를 확인해보자.

fdt 명령어 설명 (세부명령어 참조)
  https://www.denx.de/wiki/view/DULG/UBootCmdFDT#Section_5.9.7.2.
  https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841676/U-Boot+Flattened+Device+Tree

  • Uboot 에서 Kernel의 DTB 정보확인 
Kernel에서 사용하게될 DTB 정보확인

=>pri
...
mmcdev=3
mmcpart=1
fdt_addr=0x83000000
fdt_file=undefined.dtb
loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}   
.....
=> setenv fdt_file imx6sx-sdb-emmc.dtb  //DTB File 이름변경 

=> run loadfdt        //상위 명령어 실행 (eMMC or SDcard의 Device의 Partition에서 File 읽기 
49954 bytes read in 15 ms (3.2 MiB/s)

=> fdt addr ${fdt_addr}  // FDT address 설정 

=> fdt list  // DTB 파일을 볼수 있음 
....
=> fdt print // DTB 파일을 세부적으로 확인 
....

1.4 Uboot Env 분석 및 Hush Shell Script 확장 

i.MX6의 경우 이전에 TI의 Uboot Env보다 좀 더 잘 구성이 되어있어 이부분을 간단정리

=> pri
baudrate=115200
boot_fdt=try
bootargs=console=ttymxc0,115200 rdinit=/linuxrc clk_ignore_unused
bootcmd=run findfdt; mmc dev ${mmcdev}; if mmc rescan; then if run loadbootscript; then run bootscript; else if run loadimage; then run mmcboot; else run netboot; fi; fi; else run netboot; fi
bootcmd_mfg=run mfgtool_args;if iminfo ${initrd_addr}; then if test ${tee} = yes; then bootm ${tee_addr} ${initrd_addr} ${fdt_addr}; else bootz ${loadaddr} ${initrd_addr} ${fdt_addr}; fi; else echo "Run fastboot ..."; fastboot 0; fi;
bootdelay=3
bootscript=echo Running bootscript from mmc ...; source   // source command를 이용하여 boot.scr 실행 (default loadaddr) 
console=ttymxc0
emmc_ack=0
emmc_dev=3
eth1addr=c2:42:5a:9f:cd:09
ethact=ethernet@02188000
ethaddr=26:E1:2C:C4:C7:C6
ethprime=eth0
fastboot_bytes=adc00
fastboot_dev=mmc
fdt_addr=0x83000000       // Kernel용 DTB 주소 (DRAM) 
fdt_file=undefined        // Kernel용 DTB File 이름
fdt_high=0xffffffff       // DTB MAX DRAM MAX 
fdtcontroladdr=bdf35a08  // Uboot 용 DTB 주소 (DRAM)  
filesize=adc00
findfdt=if test $fdt_file = undefined; then setenv fdt_file imx6sx-sdb-emmc.dtb; fi;
image=zImage
initrd_addr=0x86800000
initrd_high=0xffffffff
ip_dyn=yes
kboot=bootz
loadaddr=0x80800000
loadbootscript=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};  // eMMC에서 bootscript 읽어서 쉽게확장
loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file} // Kernel DTB File 읽기
loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image}  // Kernel Image
loadm4image=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${m4image} // qspi용 Kernel Image로 추정
loadtee=fatload mmc ${mmcdev}:${mmcpart} ${tee_addr} ${tee_file}  // 보안 boot 
m4_qspi_cs=2
m4boot=sf probe 1:${m4_qspi_cs}; bootaux 0x78000000
m4image=m4_qspi.bin
mfgtool_args=setenv bootargs console=${console},${baudrate} rdinit=/linuxrc clk_ignore_unused
mmcargs=setenv bootargs console=${console},${baudrate} root=${mmcroot}
mmcautodetect=yes
mmcboot=echo Booting from mmc ...; run mmcargs; if test ${tee} = yes; then run loadfdt; run loadtee; bootm ${tee_addr} - ${fdt_addr}; else if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi; fi;
mmcdev=3
mmcpart=1
mmcroot=/dev/mmcblk3p2 rootwait rw
netargs=setenv bootargs console=${console},${baudrate} root=/dev/nfs ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp
netboot=echo Booting from net ...; run netargs; if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; ${get_cmd} ${image}; if test ${tee} = yes; then ${get_cmd} ${tee_addr} ${tee_file}; ${get_cmd} ${fdt_addr} ${fdt_file}; bootm ${tee_addr} - ${fdt_addr}; else if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;fi;
panel=Hannstar-XGA
script=boot.scr  // FAT에서 boot.scr를 만들어 설정확장
sd_dev=3
serial#=121a59d4f21fe636
soc_type=imx6sx
tee=no
tee_addr=0x84000000
tee_file=uTee-6sxsdb
update_m4_from_sd=if sf probe 1:${m4_qspi_cs}; then if run loadm4image; then setexpr fw_sz ${filesize} + 0xffff; setexpr fw_sz ${fw_sz} / 0x10000; setexpr fw_sz ${fw_sz} * 0x10000; sf erase 0x0 ${fw_sz}; sf write ${loadaddr} 0x0 ${filesize}; fi; fi


  • i.MX6의 경우 HW bootmode에 따라 bootcmd의 실행변경
  1. bootcmd: 일반 boot  Mode
  2. bootcmd_mfg: Download Mode (uuu라는 Program을 이용하여 fastboot이용)

  • Download Mode (fastboot이용)
i.MX6는 Download Mode 일 경우 USB를 통해서 Window/Linux의 uuu(mfgtools) Program을 이용하여 boot가 가능하다.
PC (USB Host) / i.MX6 (USB Device) 로 동작이되며, Uboot에서 fastboot를 이용하여 usb로 각 Data를 Download를 하고, eMMC or SDCard를 Write를 진행한다.
PC용 fastboot로는 연결해보지 못하고 오직 uuu라는 Program만 사용해봄

  • bootcmd 일 경우 
상위를 간단히 분석을 해보면 확장을 위해서 별도의 Uboot Script 파일을 읽어 User에서 Uboot의 설정을 변경가능하도록 만들었다.

  • loadbootscript (확장의 용이성)
Linux의 User에서 수정가능한 Uboot Script(boot.scr)가 존재하며, Linux User는 Uboot Env를 쉽게 이를 이용하여 변경이 가능하다.

TI-Sitara Uboot Script 및 Device Tree 설정
  https://ahyuo79.blogspot.com/2015/08/uboot-script-device-tree.html


1.5 Uboot Env 값 고정값으로 설정 

Env값들 중 변경 불가능 값들이 존재하여 관련된 소스분석 아래와 같이 board init 할때 마다 env_set 관련 function을 이용하여 직접 설정

$ cd uboot
$ vi include/configs/mx6sxsabresd.h   // 기본적인 uboot의 default env 값으로 saveenv 로 user가 각각 변경가능

#define CONFIG_EXTRA_ENV_SETTINGS \       //default env 값들 (saveenv 변경가능하지만, 변경불가능한 값 원인분석)
...............

#define CONFIG_BOOTCOMMAND \             // bootcmd 값  (saveenv 변경가능) 
           "run findfdt; " \
           "mmc dev ${mmcdev}; if mmc rescan; then " \
                   "if run loadbootscript; then " \
                           "run bootscript; " \
                   "else " \
                           "if run loadimage; then " \
                                   "run mmcboot; " \
                           "else run netboot; " \
                           "fi; " \
                   "fi; " \
           "else run netboot; fi"

//mmcdev 와 mmcroot의 경우 saveenv로 변경을해도 board_init 할때마다 새로설정됨  
$ vi board/freescale/common/mmc.c  
....
void board_late_mmc_env_init(void)
{
        char cmd[32];
        char mmcblk[32];
        u32 dev_no = mmc_get_env_dev();

        if (!check_mmc_autodetect())
                return;

//mmcdev 값 고정  , saveenv로 변경해도 기본값으로 설정 
        env_set_ulong("mmcdev", dev_no);

//mmcroot 값 고정 , saveenv로 변경해도 기본값으로 설정 
        /* Set mmcblk env */
        sprintf(mmcblk, "/dev/mmcblk%dp2 rootwait rw",
                mmc_map_to_kernel_blk(dev_no));
        env_set("mmcroot", mmcblk);

        sprintf(cmd, "mmc dev %d", dev_no);
        run_command(cmd, 0);
}


2. Uboot 의 Command Script 관리 

예전의 Uboot 보다 점점 많은 명령어를 지원해주고 있으며, fastboot를 비롯하여, 각종 filesystem도 마음대로 접근이 가능하며,
다양한 Hardware Interface도 지원을 해주고 있어 Hush shell 를 잘 이용하면 일반 Shell Script 못지않게 잘 사용할 수 있을 것 같다.

각종 사용되어지는 Image 관리부터 각각의 Interface check 기능 및다양한 Program을 쉽게 작성이 가능할 것 같다.

Hush Shell Script
  https://sites.google.com/site/manisbutareed/bringing-my-beagles-to-heel/5-to-be-continued

// Android의 fastboot 기능 
fastboot  - run as a fastboot usb or udp device
// Partition 
gpt       - GUID Partition Table
part      - disk partition related commands

// File system 관리 명령어 
fstype    - Look up a filesystem type
fatsize   - determine a file's size

ext2load  - load binary file from a Ext2 filesystem
ext2ls    - list files in a directory (default /)
ext4load  - load binary file from a Ext4 filesystem
ext4ls    - list files in a directory (default /)
ext4size  - determine a file's size
ext4write - create a file in the root directory

fatinfo   - print information about filesystem
fatload   - load binary file from a dos filesystem
fatls     - list files in a directory (default /)
fatmkdir  - create a directory
fatrm     - delete a file
fatsize   - determine a file's size
fatwrite  - write file into a dos filesystem

// DTB 관리 
fdt       - flattened device tree utility commands


2.1  Uboot의 mmc command 사용


=> mmc
mmc - MMC sub system

Usage:
mmc info - display info of the current MMC device
mmc read addr blk# cnt
mmc write addr blk# cnt
mmc erase blk# cnt
mmc rescan
mmc part - lists available partition on current mmc device
mmc dev [dev] [part] - show or set current mmc device [partition]
mmc list - lists available devices
mmc hwpartition [args...] - does hardware partitioning
  arguments (sizes in 512-byte blocks):
    [user [enh start cnt] [wrrel {on|off}]] - sets user data area attributes
    [gp1|gp2|gp3|gp4 cnt [enh] [wrrel {on|off}]] - general purpose partition
    [check|set|complete] - mode, complete set partitioning completed
  WARNING: Partitioning is a write-once setting once it is set to complete.
  Power cycling is required to initialize partitions after set to complete.
mmc bootbus dev boot_bus_width reset_boot_bus_width boot_mode
 - Set the BOOT_BUS_WIDTH field of the specified device
mmc bootpart-resize   
 - Change sizes of boot and RPMB partitions of specified device
mmc partconf dev [boot_ack boot_partition partition_access]
 - Show or change the bits of the PARTITION_CONFIG field of the specified device
mmc rst-function dev value
 - Change the RST_n_FUNCTION field of the specified device
   WARNING: This is a write-once field and 0 / 1 / 2 are the only valid values.
mmc setdsr  - set DSR register value

MMC 사용예제
  https://forums.xilinx.com/t5/ACAP-and-SoC-Boot-and/U-boot-Mmc-read-write/td-p/891742

  • mmc 기본확인
=> mmc list
FSL_SDHC: 1
FSL_SDHC: 2 (SD)
FSL_SDHC: 3 (eMMC)

=> mmc dev 3   //mmc device 선택 
switch to partitions #0, OK
mmc3(part 0) is current device

=> mmc part

Partition Map for MMC device 3  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     8192            45668           304dec68-01     0c Boot
  2     57344          445688          304dec68-02     83
  3     507904          524288          304dec68-03     83

=> mmc dev 2  //mmc device 선택 
switch to partitions #0, OK
mmc2 is current device

=> mmc part

Partition Map for MMC device 2  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     129             3911551         02751898-01     0c


  • mmc erase/write/read 방법
//SD Card의 Partition1 에서 File read 
=> fatload mmc 2:1 ${loadaddr} core-lora-image-imx6sxsabresd.wic 
528482304 bytes read in 35944 ms (14 MiB/s)

=> mmc dev 3   //mmc device 선택 
switch to partitions #0, OK
mmc3(part 0) is current device

=> pri loadaddr
loadaddr=0x80800000

//0x82400000  = 0x80800000 + 0x1C00000 ( 57344*512)
// Start Sector 0xE000(57344) 
// Num Sectors 0x6CCF8‬(445688)
// mmc read/write/erase HEX로 밖에 동작이 안됨 

=> mmc erase 0xE000 0x6CCF8‬ //eMMC erase
MMC erase: dev # 3, block # 57344, count 445688 ...

=> mmc write 0x82400000 0xE000 0x6CCF8‬ //eMMC Write 
MMC write: dev # 3, block # 57344, count 445688 ... 445688 blocks written: OK

=> mmc read 0x82400000 0xE000 0x6CCF8‬ //eMMC Write 
MMC read: dev # 3, block # 57344, count 445688 ... 445688 blocks read: OK

상위 정보는 linux application에서 fdisk -l 의 정보와 동일하며, image는 dd를 이용하여 편집가능

2.2 Uboot Script 생성

상위에서 사용했던 방법들을 간단히 정리하여 Script로 만들어서 이를 확장하는 방법을 알아보자.


  • 환경변수로 분할한 후 마지막에 연결
SDcard에서 image를 읽고 write한 후 bootscript 삭제
$ vi myboot0.cmd
setenv upgrade_read fatload mmc 2:1 ${loadaddr} core-lora-image-imx6sxsabresd.wic 
setenv upgrade_write mmc write 0x82400000 0xE000 0x6CCF8‬ 
setenv upgrade_remove fatrm mmc 2:1 ${script}
setenv upgradelog_start         echo ======== Simple Upgrade Script
setenv upgradelog_success       echo ======== Succeed to upgrade the firmware
setenv upgradelog_success_read  echo ======== Succeed to read the firmware
setenv upgradelog_success_write echo ======== Succeed to wirte the firmware
setenv upgradelog_fail_read     echo ======== Failed to read a firmware file 
setenv upgradelog_fail_write    echo ======== Failed to write a firmware file 
setenv upgrade_targets read write remove 
setenv upgrade_loop "for target in ${upgrade_targets}; do run upgrade_${target}; done" 
setenv upgrade_select "run upgradelog_start; if run upgrade_read; then if run upgrade_write; then run upgrade_remove; else run upgradelog_fail_write; fi; else run upgradelog_fail_read; fi"
run upgrade_select


  • 전체순차적으로 실행 
SDcard 삽입시 계속 Loop에 지속적으로 실행되며, SD Card 제거시 동작 중지
$ vi myboot1.cmd
echo ======== Simple Version Upgrade Script;
setenv targetaddr ${loadaddr};
if test $version = 1; then
   echo "======== checked your firmware version";
   setenv upgrade_read fatload mmc 2:1 ${loadaddr} core-lora-image-imx6sxsabresd.wic
   setenv upgrade_write mmc write 0x82400000 0xE000 0x6CCF8
   if run upgrade_read; then
      echo "======== Ok found a SD card upgrade file";
      echo "======== Start to upgrade a firmware";

      if run upgrade_write; then
         echo "======== Ok write the firmware into eMMC";
         setenv version 2; 
         mw  ${targetaddr} 0 100;
         mw  ${targetaddr} 0x43435553 1;
         setexpr targetaddr $targetaddr + 4;
         mw  ${targetaddr} 0x20535345 1;
         fatwrite mmc 2:1 ${loadaddr} result.txt 8         
      else
         echo "======== failed to write the image to eMMC";
         mw  ${targetaddr} 0 100;
         mw  ${targetaddr} 0x4c494146 1;
         setexpr targetaddr $targetaddr + 4;
         mw  ${targetaddr} 0x20 1;
         fatwrite mmc 2:1 ${loadaddr} result.txt
         setenv version 0
      fi
   else
      echo "======== failed to read the image from SD card";
      mw  ${targetaddr} 0 100;
      mw  ${targetaddr} 0x4c494146 1;
      setexpr targetaddr $targetaddr + 4;
      mw  ${targetaddr} 0x20 1;
      setenv version 0;
   fi
else
   echo "======== its same version";
   mw  ${targetaddr} 0 100;
   mw  ${targetaddr} 0x454d4153 1;
   setexpr targetaddr $targetaddr + 4;
   mw  ${targetaddr} 0x52455620 1;
   setexpr targetaddr $targetaddr + 4;
   mw  ${targetaddr} 0x4e4f4953 1;
   fatwrite mmc 2:1 ${loadaddr} result.txt
fi
saveenv;
reset;
boot script example
  https://boundarydevices.com/boot-scripts-for-main-line-u-boot-on-i-mx6/


  • boot scirpt 생성

아래와 같이 기본이 PowerPC로 되어있으므로, 가능하다면, ARM으로 변경해서 사용하자. (아래와 같이 사용해도 동작가능)

$ mkimage -T script -C none -n 'Uboot Script File' -d myboot0.cmd boot.scr
Image Name:   Uboot Script File
Created:      Fri May 15 17:00:50 2020
Image Type:   PowerPC Linux Script (uncompressed)
Data Size:    271 Bytes = 0.26 kB = 0.00 MB
Load Address: 00000000
Entry Point:  00000000
Contents:
   Image 0: 263 Bytes = 0.26 kB = 0.00 MB


$ mkimage -T script -C none -n 'Uboot Script File' -d myboot1.cmd boot.scr
Image Name:   Uboot Script File
Created:      Mon May 18 10:56:40 2020
Image Type:   PowerPC Linux Script (uncompressed)
Data Size:    979 Bytes = 0.96 kB = 0.00 MB
Load Address: 00000000
Entry Point:  00000000
Contents:
   Image 0: 971 Bytes = 0.95 kB = 0.00 MB


  • boot script 적용

=> setenv version 1 // version 입력
=> setenv loadbootscript fatload mmc 2:1 ${loadaddr} ${script}; // SD Card Read로 변경 
=> saveenv
=> reset

setenv loadbootscript fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};

  https://www.denx.de/wiki/view/DULG/UBootScripts

이를 이용하여 간단히 Upgrade script 도 간단히 만들수 있다.

8/14/2015

Uboot Script 이해 및 Device Tree Boot 설정 (Sitara)

1. Uboot Env 환경변수 

setenv or set : 명령이용하여 환경변수 설정가능 uboot에서 많은 환경변수를 제공하며, script기능도 제공

1.1 Uboot Hush Script 이해

환경변수 설정과 기본 script 실행하는 방법은 아래와 같으며, Uboot에서 사용하는 Command는 Uboot 빌드시 CONFIG 옵션에 따라
변경되기 때문에 차이는 있지만, 기본 Command들은 대체적으로 알아두자.

  • UBoot의 기본 env 와 command 이해 
  1. bootcmd:  uboot가 기본적으로 실행되는 변수 (가장중요)
  2. 이외에 암묵적으로 많이 사용하는 환경변수가 존재 (stdin,stdout, 등 ) 
  3. script의 기본은 uboot cmd의 나열로 구성하고 환경변수 및 구분자를 세미콜론사용
  4. run을 이용하여 만들어진 script을 실행가능 
  5. setenv 이용하여 환경변수 및 script 생성  

  • UBoot Script 의 확장이해 
  1. if <list>; then <command list>; [elif <list>; then <list>; ] [else <list>; then <list>;]
  2. while <list>; do <list>; done
  3. until <list>; do <list>; done
  4. for <name> in <word list>; do <list> ; done

1,2,3 앞에 test command를 이용하여 비교가 가능하며,  뒤에 는 script or 환경변수를 넣으면 된다.   

  http://www.compulab.co.il/utilite-computer/wiki/index.php/U-Boot_Scripts

1.2 Uboot Hush Script 의 예제 

위에서 확장으로 사용되는 예제들을 한번 살펴보자.

  • Uboot Script  if 문 test 예제 
test command를 이용하여 비교하고, 그 결과을 적용

findfdt=if test $board_name = AM43EPOS; then setenv fdtfile am43x-epos-evm.dtb; fi; if test $board_name = AM43__GP; then setenv fdtfile am437x-gp-evm.dtb; fi; if test $board_name = AM43__SK; then setenv fdtfile am437x-sk-evm.dtb; fi; if test $fdtfile = undefined; then echo WARNING: Could not determine device tree; fi; // if문 예제 

  • Uboot Script for 문 예제 
boot_target 이라는 word_list에서 target이라는 변수를 만들어 반복문을 만들어 여러 bootcmd_target을 실행한다.

boot_targets=mmc0 legacy_mmc0 mmc1 legacy_mmc1 nand0 pxe dhcp    // target list 
distro_bootcmd=for target in ${boot_targets}; do run bootcmd_${target}; done  //for boot_targets에서 환경변수에서 target을 추출하여 bootcmd_x 실행
bootcmd_dhcp=run boot_net_usb_start; if dhcp ${scriptaddr} ${boot_script_dhcp}; then source ${scriptaddr}; fi
bootcmd_legacy_mmc0=setenv mmcdev 0; setenv bootpart 0:2 ; run mmcboot
bootcmd_legacy_mmc1=setenv mmcdev 1; setenv bootpart 1:2 ; run mmcboot
bootcmd_mmc0=setenv devnum 0; run mmc_boot
bootcmd_mmc1=setenv devnum 1; run mmc_boot
bootcmd_nand=run nandboot
bootcmd_pxe=run boot_net_usb_start; dhcp; if pxe get; then pxe boot; fi

uboot script은 쉽게 이해가능하며, 누구나 쉽게 사용가능.


1.3 외부 Uboot Script 사용방법

  • Uboot에서 Uboot Script 실행
Uboot에서 FAT에서 boot.scr를 읽어서 이를 source를 이용하여 실행하며, 보통 SDCard Boot를 했을 때 사용한다.

U-Boot# pri
...
script_addr=0x80900000
loadbootscript=fatload mmc 0 ${script_addr} boot.scr
bootscript= echo Running bootscript from MMC/SD to set the ENV...; source ${script_addr}
bootcmd=if mmc init; then if run loadbootscript; then run bootscript; else if run loaduimage; then run mmcboot; else run nandboot; f
i; fi; else run nandboot; fi
...

  • 외부 Uboot Script 생성방법
$ vi boot-nfs.txt 
setenv bootargs 'console=ttyO0,115200n8 root=/dev/nfs nfsrootdebug rw rootdelay=10 mem=80M vram=4M notifyk.vpssm3_sva=0xBFD00000 nfsroot=192.168.1.100:/home/jhlee/dm8127/work/Source/ipnc_rdk/target/filesys,nolock eth=32:30:3a:63:64:3a ip=192.168.1.168 cmemk.phys_start=0x85000000 cmemk.phys_end=0x89000000 cmemk.allowOverlap=1 earlyprintk'

$ mkimage -A arm -T script -C none -d boot-nfs.txt  boot.scr // Uboot Script 생성

생성된 boot.scr를 FAT에 복사하여 실행가능하여 이외에도 상위의 if문을 비롯하여 다양한 연속적인 Uboot Script을 생성가능하다


  • mkimage 설치
Uboot안에 mkimage가 존재하지만, PATH설정를 비롯하여 귀찮아서 직접 설치
$ sudo apt-get install uboot-mkimage //mkimage가 없을 경우 설치 

  https://wiki.ubuntu.com/ARM/EditBootscr
  http://www.denx.de/wiki/DULG/UBootScripts

2. Uboot 와 Device Tree Boot 설정 

AM437x와 AM335x는 Uboot에서 손쉽게 Device Tree Boot를 설정변경이 가능하며,
이전에 Device Tree File에 대해서 설명했듯이 zImage와 dtb 파일은 filesystem의 /boot라는 곳에 저장이 되어있다.

Device Tree 관련내용
  https://ahyuo79.blogspot.com/2015/08/kernel-boot-kernel-device-tree.html

  • Uboot 와 Device Tree Boot 역할
각각의 File (zImage와 *.dtb) 들을  Load를 하면 Uboot Device Tree 기본역할은 한것이며, 이 관련 script을 수정을하면된다.


  • Device Tree Boot 설정 변경 (다양한 Kernel 및 Device Tree 선택)
Uboot Script or 환경변수 설정을 변경하여 이를 변경하자
특히 findfdt는 device tree의 file을 설정을 하는 것이며, findfdt 대신 직접 설정을 하여도 좋다.


2.1 Uboot의 boot 분석 (AM437x-EVM-GP)

이제 중요한 uboot에서 dtb을 찾고 zImage를 찾아 booting을 해보자
기본명령어는 다음과 같다

bootz ${loadaddr} - ${fdtaddr} 


FDT (Flattened Device Tree) 는  DTB (Device Tree Blob)를 말하며 관련 구조는 Device Tree Spec를 참조

  • Uboot Env MMC BOOT 분석 
  1. bootcmd : dtb를 찾아 설정 후 mmcboot / usbboot/ nand boot로 순차실행
  2. findfdt : 현재 board_name에 따라 fdtfile 에 dtb 파일설정
  3. mmcboot: mmc device를 설정하고 rescan 
  4. mmcboot: uEnv.txt (uboot Env) File이 존재한다면 찾아 설정 
  5. mmcboot: importenv는 외부에 존재 할 경우,  uenvcmd는 존재할 경우 동작  두부분 생략
  6. mmcboot: loadimage로 kernel을  load_addr로 load 한다 ( File system의 /boot) 
  7. mmcboot: loadfdt로 dtb file을 fdt_addr로 load한다   (File system의 /boot)
  8. mmcboot: mmcargs로 kernel argument 설정
  9. mmcboot: bootz ${loadaddr} - ${fdtaddr} 로 kernel과 dtb booting  


U-Boot# pri
arch=arm
baudrate=115200
board=am43xx
board_name=AM43__GP
board_rev=1.4A
bootcmd=run findfdt; run mmcboot;run usbboot;run nandboot; 
bootdelay=1
bootdir=/boot
bootenv=uEnv.txt
bootfile=zImage
bootm_size=0x10000000
bootpart=0:2
console=ttyO0,115200n8
cpu=armv7
dfu_alt_info_emmc=MLO raw 0x100 0x100 mmcpart 0;u-boot.img raw 0x300 0x1000 mmcpart 0
dfu_alt_info_mmc=boot part 0 1;rootfs part 0 2;MLO fat 0 1;spl-os-args fat 0 1;spl-os-image fat 0 1;u-boot.img fat 0 1;uEnv.txt fat 0 1
dfu_alt_info_ram=kernel ram 0x80200000 0x4000000;fdt ram 0x80f80000 0x80000;ramdisk ram 0x81000000 0x4000000
dfu_bufsiz=0x10000
eth1addr=34:b1:f7:30:fb:00
ethact=cpsw
ethaddr=34:b1:f7:30:f7:fe
fdt_addr_r=0x88000000
fdtaddr=0x88000000
fdtfile=undefined
findfdt=if test $board_name = AM43EPOS; then setenv fdtfile am43x-epos-evm.dtb; fi; if test $board_name = AM43__GP; then setenv fdtfile am437x-gp-evm.dtb; fi; if test $board_name = AM43__SK; then setenv fdtfile am437x-sk-evm.dtb; fi; if test $fdtfile = undefined; then echo WARNING: Could not determine device tree; fi; 
importbootenv=echo Importing environment from mmc ...; env import -t $loadaddr $filesize
kernel_addr_r=0x82000000
loadaddr=0x82000000
loadbootenv=load ${devtype} ${devnum} ${loadaddr} ${bootenv}
loadfdt=load ${devtype} ${bootpart} ${fdtaddr} ${bootdir}/${fdtfile}
loadimage=load ${devtype} ${bootpart} ${loadaddr} ${bootdir}/${bootfile}
loadramdisk=load ${devtype} ${devnum} ${rdaddr} ramdisk.gz
mmcargs=setenv bootargs console=${console} ${optargs} root=${mmcroot} rootfstype=${mmcrootfstype}
mmcboot=mmc dev ${mmcdev}; setenv devnum ${mmcdev}; setenv devtype mmc; if mmc rescan; then echo SD/MMC found on device ${devnum};if run loadbootenv; then echo Loaded environment from ${bootenv};run importbootenv;fi;if test -n $uenvcmd; then echo Running uenvcmd ...;run uenvcmd;fi;if run loadimage; then run loadfdt; echo Booting from mmc${mmcdev} ...; run mmcargs; bootz ${loadaddr} - ${fdtaddr}; fi;fi;
mmcdev=0
mmcroot=/dev/mmcblk0p2 rw
mmcrootfstype=ext4 rootwait
mtdids=nand0=nand.0
mtdparts=mtdparts=nand.0:256k(NAND.SPL),256k(NAND.SPL.backup1),256k(NAND.SPL.backup2),256k(NAND.SPL.backup3),512k(NAND.u-boot-spl-os),1m(NAND.u-boot),256k(NAND.u-boot-env),256k(NAND.u-boot-env.backup1),7m(NAND.kernel),-(NAND.file-system)
nandargs=setenv bootargs console=${console} ${optargs} root=${nandroot} rootfstype=${nandrootfstype}
nandboot=echo Booting from nand ...; run nandargs; nand read ${fdtaddr} NAND.u-boot-spl-os; nand read ${loadaddr} NAND.kernel; bootz ${loadaddr} - ${fdtaddr}
nandroot=ubi0:rootfs rw ubi.mtd=NAND.file-system,4096
nandrootfstype=ubifs rootwait=1
netargs=setenv bootargs console=${console} ${optargs} root=/dev/nfs nfsroot=${serverip}:${rootpath},${nfsopts} rw ip=dhcp
netboot=echo Booting from network ...; setenv autoload no; dhcp; tftp ${loadaddr} ${bootfile}; tftp ${fdtaddr} ${fdtfile}; run netargs; bootz ${loadaddr} - ${fdtaddr}
nfsopts=nolock
partitions=uuid_disk=${uuid_gpt_disk};name=rootfs,start=2MiB,size=-,uuid=${uuid_gpt_rootfs}
ramargs=setenv bootargs console=${console} ${optargs} root=${ramroot} rootfstype=${ramrootfstype}
ramdisk_addr_r=0x88080000
ramroot=/dev/ram0 rw
ramrootfstype=ext2
rdaddr=0x88080000
rootpath=/export/rootfs
soc=am33xx
static_ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
stderr=serial
stdin=serial
stdout=serial
usbargs=setenv bootargs console=${console} ${optargs} root=${usbroot} rootfstype=${usbrootfstype}
usbboot=setenv devnum ${usbdev}; setenv devtype usb; usb start ${usbdev}; if usb dev ${usbdev}; then 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 loadimage; then run loadfdt; echo Booting from usb ${usbdev}...; run usbargs;bootz ${loadaddr} - ${fdtaddr}; fi;fi;usb stop ${usbdev};
usbdev=0
usbnet_devaddr=34:b1:f7:30:fb:00
usbroot=/dev/sda2 rw
usbrootfstype=ext4 rootwait
vendor=ti
ver=U-Boot 2014.07-gfb6ab76 (Jul 06 2015 - 16:10:49)

Environment size: 4128/65532 bytes 

  • Uboot Env ( NFS - Network 고정 IP Mode)
현재 dhcp를 사용하며 ip가 바뀌어서 고정 ip로 변경하기로 결정.
만약 AP에서 dhcp 세부설정이 가능하다면 위와 같이 사용.

setenv ipaddr '192.168.1.101'
setenv serverip '192.168.1.100'
setenv netmask '255.255.255.0'
setenv rootpath '/home/jhlee/am437x/targetNFS'
setenv netargs 'setenv bootargs console=${console} ${optargs} root=/dev/nfs nfsroot=${serverip}:${rootpath},${nfsopts} rw ip=${ipaddr}' 
setenv netboot1 'echo Booting from network ...; setenv autoload no; tftp ${loadaddr} ${bootfile}; tftp ${fdtaddr} ${fdtfile}; run netargs; bootz ${loadaddr} - ${fdtaddr}'

setenv bootcmd 'run findfdt; run netboot1;'
setenv bootfile 'zImage'
setenv fdtfile 'am437x-gp-evm.dtb'  //직접 설정 후 run findfdt를 삭제가능 


Linux server의 /tftpboot에 bootfile과 fdtfile을 보관해야한다.


2.2 Uboot Env 분석 (AM335x SK, Start Kit )

AM437x와 거의 동일하며 UBOOT에서  zImage와 *.dtb을 변경을 해주면된다.

  • Device Tree Booting Command
bootz ${loadaddr} - ${fdtaddr} 


  • Uboot Env 분석 
=>pri
arch=arm
args_fit=setenv bootargs console=${console} 
args_mmc=run finduuid;setenv bootargs console=${console} ${optargs} root=PARTUUID=${uuid} rw rootfstype=${mmcrootfstype}
baudrate=115200
board=am335x
board_name=A335X_SK
board_rev=1.2B
board_serial=34124P192908
boot_a_script=load ${devtype} ${devnum}:${distro_bootpart} ${scriptaddr} ${prefix}${script}; source ${scriptaddr}
boot_efi_binary=load ${devtype} ${devnum}:${distro_bootpart} ${kernel_addr_r} efi/boot/bootarm.efi; if fdt addr ${fdt_addr_r}; then bootefi ${kernel_addr_r} ${fdt_addr_r};elsebootefi ${kernel_addr_r} ${fdtcontroladdr};fi
boot_extlinux=sysboot ${devtype} ${devnum}:${distro_bootpart} any ${scriptaddr} ${prefix}extlinux/extlinux.conf
boot_fdt=try
boot_fit=0
boot_net_usb_start=usb start
boot_prefixes=/ /boot/
boot_script_dhcp=boot.scr.uimg
boot_scripts=boot.scr.uimg boot.scr
boot_targets=mmc0 legacy_mmc0 mmc1 legacy_mmc1 nand0 pxe dhcp 
bootcmd=if test ${boot_fit} -eq 1; then run update_to_fit;fi;run findfdt; run init_console; run envboot; run distro_bootcmd
bootcmd_dhcp=run boot_net_usb_start; if dhcp ${scriptaddr} ${boot_script_dhcp}; then source ${scriptaddr}; fi
bootcmd_legacy_mmc0=setenv mmcdev 0; setenv bootpart 0:2 ; run mmcboot
bootcmd_legacy_mmc1=setenv mmcdev 1; setenv bootpart 1:2 ; run mmcboot
bootcmd_mmc0=setenv devnum 0; run mmc_boot
bootcmd_mmc1=setenv devnum 1; run mmc_boot
bootcmd_nand=run nandboot
bootcmd_pxe=run boot_net_usb_start; dhcp; if pxe get; then pxe boot; fi
bootcount=4
bootdelay=2
bootdir=/boot
bootenvfile=uEnv.txt
bootfile=zImage
bootm_size=0x10000000
bootpart=0:2
bootscript=echo Running bootscript from mmc${mmcdev} ...; source ${loadaddr}
console=ttyO0,115200n8
cpu=armv7
dfu_alt_info_emmc=rawemmc raw 0 3751936
dfu_alt_info_mmc=boot part 0 1;rootfs part 0 2;MLO fat 0 1;MLO.raw raw 0x100 0x100;u-boot.img.raw raw 0x300 0x400;spl-os-args.raw raw 0x80 0x80;spl-os-image.raw raw 0x900 0x2000;spl-os-args fat 0 1;spl-os-image fat 0 1;u-boot.img fat 0 1;uEnv.txt fat 0 1
dfu_alt_info_nand=SPL part 0 1;SPL.backup1 part 0 2;SPL.backup2 part 0 3;SPL.backup3 part 0 4;u-boot part 0 5;u-boot-spl-os part 0 6;kernel part 0 8;rootfs part 0 9
dfu_alt_info_ram=kernel ram 0x80200000 0xD80000;fdt ram 0x80F80000 0x80000;ramdisk ram 0x81000000 0x4000000
distro_bootcmd=for target in ${boot_targets}; do run bootcmd_${target}; done
efi_dtb_prefixes=/ /dtb/ /dtb/current/
envboot=mmc dev ${mmcdev}; if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadbootscript; then run bootscript;else if run loadbootenv; then echo Loaded env from ${bootenvfile};run importbootenv;fi;if test -n $uenvcmd; then echo Running uenvcmd ...;run uenvcmd;fi;fi;fi;
eth1addr=d4:94:a1:86:70:e1
ethaddr=d4:94:a1:86:70:e0
fdt_addr_r=0x88000000
fdtaddr=0x88000000
fdtcontroladdr=8ef282f8
fdtfile=undefined
findfdt=if test $board_name = A335BONE; then setenv fdtfile am335x-bone.dtb; fi; if test $board_name = A335BNLT; then setenv fdtfile am335x-boneblack.dtb; fi; if test $board_name = BBG1; then setenv fdtfile am335x-bonegreen.dtb; fi; if test $board_name = A33515BB; then setenv fdtfile am335x-evm.dtb; fi; if test $board_name = A335X_SK; then setenv fdtfile am335x-evmsk.dtb; fi; if test $board_name = A335_ICE; then setenv fdtfile am335x-icev2.dtb; fi; if test $fdtfile = undefined; then echo WARNING: Could not determine device tree to use; fi; 
finduuid=part uuid mmc ${bootpart} uuid
fit_bootfile=fitImage.itb
fit_loadaddr=0x88000000
importbootenv=echo Importing environment from mmc${mmcdev} ...; env import -t ${loadaddr} ${filesize}
init_console=if test $board_name = A335_ICE; then setenv console ttyO3,115200n8;else setenv console ttyO0,115200n8;fi;
kernel_addr_r=0x82000000
load_efi_dtb=load ${devtype} ${devnum}:${distro_bootpart} ${fdt_addr_r} ${prefix}${efi_fdtfile}
loadaddr=0x82000000
loadbootenv=fatload mmc ${mmcdev} ${loadaddr} ${bootenvfile}
loadbootscript=load mmc ${mmcdev} ${loadaddr} boot.scr
loadfdt=load ${devtype} ${bootpart} ${fdtaddr} ${bootdir}/${fdtfile}
loadfit=run args_fit; bootm ${loadaddr}#${fdtfile};
loadimage=load ${devtype} ${bootpart} ${loadaddr} ${bootdir}/${bootfile}
loadramdisk=load mmc ${mmcdev} ${rdaddr} ramdisk.gz
mmc_boot=if mmc dev ${devnum}; then setenv devtype mmc; run scan_dev_for_boot_part; fi
mmcboot=mmc dev ${mmcdev}; setenv devnum ${mmcdev}; setenv devtype mmc; if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadimage; then if test ${boot_fit} -eq 1; then run loadfit; else run mmcloados;fi;fi;fi;
mmcdev=0
mmcloados=run args_mmc; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootz ${loadaddr} - ${fdtaddr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
mmcrootfstype=ext4 rootwait
mtdids=nand0=nand.0
mtdparts=mtdparts=nand.0:128k(NAND.SPL),128k(NAND.SPL.backup1),128k(NAND.SPL.backup2),128k(NAND.SPL.backup3),256k(NAND.u-boot-spl-os),1m(NAND.u-boot),128k(NAND.u-boot-env),128k(NAND.u-boot-env.backup1),8m(NAND.kernel),-(NAND.file-system)
nandargs=setenv bootargs console=${console} ${optargs} root=${nandroot} rootfstype=${nandrootfstype}
nandboot=echo Booting from nand ...; run nandargs; nand read ${fdtaddr} NAND.u-boot-spl-os; nand read ${loadaddr} NAND.kernel; bootz ${loadaddr} - ${fdtaddr}
nandroot=ubi0:rootfs rw ubi.mtd=NAND.file-system,2048
nandrootfstype=ubifs rootwait=1
netargs=setenv bootargs console=${console} ${optargs} root=/dev/nfs nfsroot=${serverip}:${rootpath},${nfsopts} rw ip=dhcp
netboot=echo Booting from network ...; setenv autoload no; dhcp; run netloadimage; run netloadfdt; run netargs; bootz ${loadaddr} - ${fdtaddr}
netloadfdt=tftp ${fdtaddr} ${fdtfile}
netloadimage=tftp ${loadaddr} ${bootfile}
nfsopts=nolock
partitions=uuid_disk=${uuid_gpt_disk};name=rootfs,start=2MiB,size=-,uuid=${uuid_gpt_rootfs}
pxefile_addr_r=0x80100000
ramargs=setenv bootargs console=${console} ${optargs} root=${ramroot} rootfstype=${ramrootfstype}
ramboot=echo Booting from ramdisk ...; run ramargs; bootz ${loadaddr} ${rdaddr} ${fdtaddr}
ramdisk_addr_r=0x88080000
ramroot=/dev/ram0 rw
ramrootfstype=ext2
rdaddr=0x88080000
rootpath=/export/rootfs
scan_dev_for_boot=echo Scanning ${devtype} ${devnum}:${distro_bootpart}...; for prefix in ${boot_prefixes}; do run scan_dev_for_extlinux; run scan_dev_for_scripts; done;run scan_dev_for_efi;
scan_dev_for_boot_part=part list ${devtype} ${devnum} -bootable devplist; env exists devplist || setenv devplist 1; for distro_bootpart in ${devplist}; do if fstype ${devtype} ${devnum}:${distro_bootpart} bootfstype; then run scan_dev_for_boot; fi; done
scan_dev_for_efi=setenv efi_fdtfile ${fdtfile}; if test -z "${fdtfile}" -a -n "${soc}"; then setenv efi_fdtfile ${soc}-${board}${boardver}.dtb; fi; for prefix in ${efi_dtb_prefixes}; do if test -e ${devtype} ${devnum}:${distro_bootpart} ${prefix}${efi_fdtfile}; then run load_efi_dtb; fi;done;if test -e ${devtype} ${devnum}:${distro_bootpart} efi/boot/bootarm.efi; then echo Found EFI removable media binary efi/boot/bootarm.efi; run boot_efi_binary; echo EFI LOAD FAILED: continuing...; fi; setenv efi_fdtfile
scan_dev_for_extlinux=if test -e ${devtype} ${devnum}:${distro_bootpart} ${prefix}extlinux/extlinux.conf; then echo Found ${prefix}extlinux/extlinux.conf; run boot_extlinux; echo SCRIPT FAILED: continuing...; fi
scan_dev_for_scripts=for script in ${boot_scripts}; do if test -e ${devtype} ${devnum}:${distro_bootpart} ${prefix}${script}; then echo Found U-Boot script ${prefix}${script}; run boot_a_script; echo SCRIPT FAILED: continuing...; fi; done
scriptaddr=0x80000000
soc=am33xx
spiargs=setenv bootargs console=${console} ${optargs} root=${spiroot} rootfstype=${spirootfstype}
spiboot=echo Booting from spi ...; run spiargs; sf probe ${spibusno}:0; sf read ${loadaddr} ${spisrcaddr} ${spiimgsize}; bootz ${loadaddr}
spibusno=0
spiimgsize=0x362000
spiroot=/dev/mtdblock4 rw
spirootfstype=jffs2
spisrcaddr=0xe0000
static_ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off
stderr=serial@44e09000
stdin=serial@44e09000
stdout=serial@44e09000
update_to_fit=setenv loadaddr ${fit_loadaddr}; setenv bootfile ${fit_bootfile}
usb_boot=usb start; if usb dev ${devnum}; then setenv devtype usb; run scan_dev_for_boot_part; fi
usbnet_devaddr=de:ad:be:ef:00:01
vendor=ti
ver=U-Boot 2016.05-g6c5519b6fc (Dec 14 2016 - 19:14:27 -0500)

Environment size: 8557/131068 bytes

9/23/2014

IMAGE 수정 및 boot.scr 관리

1. Uboot Script 

Uboot Script 이며, Uboot 에서 사용하는 Command들을 나열하여 사용하는 일종의 Shell Script이라고 생각하면 되겠다.
boot.txt or boot.cmd 로 uboot command를 정의한 후 이를 mkimage를 이용하여 변형을 해주고, Uboot에서 이를 load에서 해서 이 Uboot Script를 사용하면 된다.

  https://www.denx.de/wiki/DULG/UBootScripts


1.1 How to make boot.scr

 mkimage -A arm -T script -C none -n "Boot.scr for odroid" -d ./boot.txt ./boot.scr 
  • boot.txt : string 
  • boot.scr : result

1.2 Uboot 환경변수 설정소스 파악  

기본적으로 Uboot에서 설정되는 환경설정값들을 각각의 EVM or Board마다 다르므로, 본인의 소스 위치를 파악하여 알아보자.

Uboot 에서 BOOTCOMAND는 bootcmd 의 환경설정값 이며, boot.scr 안에서 Kernel를 Load하고 본인이 원하는 기능을 추가하여 넣자.

  • Uboot 의 CONFIG_BOOTCOMMAND (bootcmd ) 
Uboot에서 bootcmd 설정

$ vi /include/configs/smdk4412.h  //EXYNOS의 UBOOT bootcmd 설정 
#if defined(CONFIG_HKDK4412) && defined(CONFIG_EXYNOS_PRIME)
    #define CONFIG_BOOTCOMMAND  \
        " mmc rescan 0:1; mmc rescan 0:2; "     \
        " if run loadbootscript_1; "            \
        "    then run bootscript; "             \
        " else "                                \
        "    if run loadbootscript_2; "         \
        "        then run bootscript; "         \
        "    else "                             \
        "        run default_bootcmd; "         \
        "    fi ;"                              \
        " fi ; "                                
   ...


  • Uboot 기본환경설정 
상위의 CONFIG_BOOTCOMMAND 와 Uboot의 전체 기본 환경설정값

$ vi ./include/env_default.h // UBOOT 환경설정 값 
const unsigned char default_environment[] = {
#endif
#if defined(CONFIG_HKDK4412) && defined(CONFIG_EXYNOS_PRIME)
    "bootscript=source 40008000\0"
    "default_bootcmd=echo >>> Run Default Bootcmd <<<;movi read kernel 0 40008000;movi read rootfs 0 41000000 100000;bootm 40008000 41000000\0"
    "loadbootscript_1=echo >>> Load Boot Script from mmc 0:1 <<<;fatload mmc 0:1 40008000 boot.scr\0"
    "loadbootscript_2=echo >>> Load Boot Script from mmc 0:2 <<<;fatload mmc 0:2 40008000 boot.scr\0"
    "usb_invert_clken=0\0"
#endif
...
#ifdef  CONFIG_BOOTCOMMAND
        "bootcmd="      CONFIG_BOOTCOMMAND              "\0"
#endif


  • Serial에서 Uboot 환경설정확인 

Exynos4412 # pri
baudrate=115200
bootargs=fb_x_res=1280 fb_y_res=720 hdmi_phy_res=720 
bootcmd= mmc rescan 0:1; mmc rescan 0:2;  if run loadbootscript_1;     then run bootscript;  else     if run loadbootscript_2;         then run bootscript;     else         run default_bootcmd;     fi ; fi ; 
bootdelay=5
bootscript=source 40008000
default_bootcmd=echo >>> Run Default Bootcmd <<<;movi read kernel 0 40008000;movi read rootfs 0 41000000 100000;bootm 40008000 41000000
ethact=usb_ether
loadbootscript_1=echo >>> Load Boot Script from mmc 0:1 <<<;fatload mmc 0:1 40008000 boot.scr
loadbootscript_2=echo >>> Load Boot Script from mmc 0:2 <<<;fatload mmc 0:2 40008000 boot.scr
preboot=setenv stdin serial,nc
stderr=serial
stdin=serial
stdout=serial
usb_invert_clken=0
usbethaddr=DE:AD:BE:EF:00:03

관련참고
  http://elinux.org/ECE597_boot.scr   ( OMAP 기준 설명)
  http://forum.odroid.com/viewtopic.php?f=52&t=1104
  https://wiki.linaro.org/Resources/HowTo/boot.scr


2. Android Image 

ODROID에서 제공하는 Android Image들은 크게 아래와 같이 3 종류인 것 같으며, 각 설정에 변경이 되는 것 같다.

Download  Site 
  http://dn.odroid.com/4412/Android/


2.1 ODROID-X2의 Android Image 종류

  1. emmc_self_installer.zip   : Image를 emmc에  굽고, emmc에 모든것이 설치됨.
  2. sd2emmc_installer.zip    :  Image를 SD카드에 굽고, emmc에 모든것이 설치됨.
  3. sd_self_installer.zip        : Image를 SD카드에 굽고  SD카드에 모든것이 설치됨.
위 설정은 boot.scr의 아래 값에 의해 결정

#setenv device   "0"
#setenv ToSDMMC  "0"

2.2 ODROID-X2의 Android Image 구조 


  • Download Image
   sd_self_installer.img


  • sd_self_installer.img의 구성 
  1.  0~100M:  BL1,BL2, UBOOT 있을 거라고 생각 
  2.  FAT:  FAT Partion만 존재.



$ fdisk -l /media/sf_SHARED/images/sd_self_installer.img 

Disk /media/sf_SHARED/images/sd_self_installer.img: 524 MB, 524288000 bytes
189 heads, 61 sectors/track, 88 cylinders, total 1024000 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00008403

                                        Device Boot      Start         End      Blocks   Id  System
/media/sf_SHARED/images/sd_self_installer.img1          204800     1023999      409600    b  W95 FAT32 

// 204800 x 512 = 104857600  100M 부터설정,  
// Blocks: 1k단위로 되는 것 같고, Start,End 512 byte 단위로 되는 것 같다 

  • /media/sf_SHARED/images/sd_self_installer.img1
// offset  104857600= 204800 x 512 bytes
$ sudo mount -o loop,offset=104857600 /media/sf_SHARED/images/sd_self_installer.img ./tmp1
or 
$ sudo mount -o loop,offset=$((512 * 204800)) /media/sf_SHARED/images/sd_self_installer.img ./tmp1

$ ls ./tmp1
bl1.bin   cache_aa   system_ac system_af  system_ai  system_al  system_ao  system_ar  tzsw.bin     userdata_ab
bl2.bin   system_aa  system_ad system_ag  system_aj  system_am  system_ap  system_as  u-boot.bin   userdata_ac
boot.scr  system_ab  system_ae system_ah  system_ak  system_an  system_aq  system_at  userdata_aa  zImage

한번 install이 되면, 그 이후에 아래의 구조가 존재하지 않는다.
Fastboot에 의해 Android 를 SD Write를 한다.


2.3 boot.scr (android)  분석 
Uboot의 boot.txt  아래의 command를 나열하고 mkimage로 header를 붙혀주면된다.

 //앞부분, Image 정보부분이라서 깨짐
# BootScript for Odroid (2013/01/28)
#
#
# Boot.scr make script
#
# mkimage -A arm -T script -C none -n "Boot.scr for odroid" -d ./boot.ini ./boot.scr
#

# EMMC Self Update
#setenv device   "0"
#setenv ToSDMMC  "0"

# SD/MMC Self Update
setenv device   "0"
setenv ToSDMMC  "1"

# EMMC Update from SD/EMMC
#setenv device   "1"
#setenv ToSDMMC  "0"

# SD/MMC Update from EMMC
#setenv device   "1"
#setenv ToSDMMC  "1"

setenv check_oldboot "check_value 1"
setenv check_device_sd "check_value ${ToSDMMC}";
setenv check_device "check_value ${device}";
setenv mmc64gb_check "check_64gb ${device}"

if run check_oldboot;then echo >> new-bootloader <<; else echo >> old-bootloader <<; reset; fi;

#------------------------------------------------------------------------------------------------------
# UBOOT ENV Erase
#------------------------------------------------------------------------------------------------------
mmc write 0 40008000 0x4CF 0x20

fatload mmc 0:1 41000000 zImage;movi w k ${device} 41000000;

fatload mmc 0:1 44000000 system_aa;
fatload mmc 0:1 45000000 system_ab;
fatload mmc 0:1 46000000 system_ac;
fatload mmc 0:1 47000000 system_ad;
fatload mmc 0:1 48000000 system_ae;
fatload mmc 0:1 49000000 system_af;
fatload mmc 0:1 4A000000 system_ag;
fatload mmc 0:1 4B000000 system_ah;
fatload mmc 0:1 4C000000 system_ai;
fatload mmc 0:1 4D000000 system_aj;
fatload mmc 0:1 4E000000 system_ak;
fatload mmc 0:1 4F000000 system_al;
fatload mmc 0:1 50000000 system_am;
fatload mmc 0:1 51000000 system_an;
fatload mmc 0:1 52000000 system_ao;
fatload mmc 0:1 53000000 system_ap;
fatload mmc 0:1 54000000 system_aq;
fatload mmc 0:1 55000000 system_ar;
fatload mmc 0:1 56000000 system_as;
fatload mmc 0:1 57000000 system_at;

fatload mmc 0:1 58000000 userdata_aa;
fatload mmc 0:1 59000000 userdata_ab;
fatload mmc 0:1 5A000000 userdata_ac;

fatload mmc 0:1 41000000 cache_aa;

fdisk -c ${device}

fastboot flash system 44000000 0 ${device};

fastboot flash userdata 58000000 0 ${device};

fastboot flash cache 41000000 0 ${device};

fatformat mmc ${device}:1;

if run check_device; then fastboot poweroff; else reset; fi;


3. Ubuntu Image

  https://wiki.odroid.com/old_product/odroid-x_u_q/odroid_u3/u3_partition_table
  • Download Site
  http://dn.odroid.com/Ubuntu_X2/
  http://odroid.in/ubuntu_14.04lts/old_images/
  http://odroid.in/ubuntu_14.04lts/


  • Download Image
   odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img


3.1 Ubuntu Image 구조 


  • Download Image
   odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img

  • Image Partition 구성 
  1. 0~2048K: BL1,BL2,UBOOT 있을 거라고 예상
  2. FAT32:   FAT가 2048K부터 구성,(약 2Mbyte)
  3. Linux :   Linux 기본 Partion


  • Partition으로 구성확인방법 

fdisk -l  xxxx.img //512 Byte 기준표시
parted -s xxxx.img unit B print // Byte 기준표시 


$ fdisk -l  odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img

Disk odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img: 5904 MB, 5904530944 bytes
255 heads, 63 sectors/track, 717 cylinders, total 11532287 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000c4046

                                                       Device Boot      Start         End      Blocks   Id  System
odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img1            4096      266239      131072    b  W95 FAT32
odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img2          266240    11532287     5633024   83  Linux


parted -s xxxxx unit B print  사용가능 (Byte 기준표시)

$ sudo parted -s /media/sf_SHARED/odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img unit B print

  http://odroid.us/mediawiki/index.php?title=Updating_from_Root_File_System_Images


B. FAT32 Partition 정보확인

Booting에 필요한 주요파일로 구성되어 있으며, 간단히 구성을 보면 다음과 같다.
  1. board.dtb  // Device Tree Binary 
  2. boot.scr  // Uboot Script 
  3. boot.ini   // Uboot Env 설정 File 
  4. zImage,uImage   // Kernel Image
  5. uInitrd       // RAM Disk Image


$ mkdir tmp1 tmp2
                     // offset  2097152  = 4096 x 512 bytes
$ sudo mount -o loop,offset=2097152   /media/sf_SHARED/odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img ./tmp1
or
$ sudo mount -o loop,offset=$((512*4096)) /media/sf_SHARED/odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img ./tmp1

$ ls ./tmp1
board.dtb  boot  boot-hdmi1080.scr  boot-hdmi1080.txt  boot-hdmi720.scr  boot-hdmi720.txt  boot.ini  boot.scr  boot.txt  uImage  uInitrd  zImage

C. Linux Partition 정보확인

Mount 되는 Linux Fliesystem 정보로 Host Linux에서 확인을 해보자.

                     // offset  136314880 = 266240 x 512 bytes 
$ sudo mount -o loop,offset=136314880   /media/sf_SHARED/odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img ./tmp2
or
$ sudo mount -o loop,offset=$((512*266240)) /media/sf_SHARED/odroidx2_20130125-linaro-ubuntu-desktop_SDeMMC_with_HDMI.img ./tmp2
$ ls ./tmp2
bin  boot  dev etc  home  initrd.img  lib  lost+found media  mnt  opt  proc  root  run  sbin selinux  srv  sys  tmp usr  var  vmlinuz




4. Uboot script 


4.1 boot.scr  (ubuntu) 

ubuntu boot.scr  설치가 아닌  boot 이며,아래와 같이 기본 설정을 해준다.

setenv initrd_high "0xffffffff"
setenv fdt_high "0xffffffff"
setenv fb_x_res "1280"
setenv fb_y_res "720"
setenv hdmi_phy_res "720"
setenv bootcmd "fatload mmc 0:1 0x40008000 zImage; fatload mmc 0:1 0x42000000 uInitrd; bootm 0x40008000 0x42000000"
setenv bootargs "console=tty1 console=ttySAC1,115200n8 fb_x_res=${fb_x_res} fb_y_res=${fb_y_res} hdmi_phy_res=${hdmi_phy_res} root=UUID=e139ce78-9841-40fe-8823-96a304a09859 rootwait ro mem=2047M"
boot


4.2 boot.scr (dnw 적용) 

setenv initrd_high "0xffffffff"
setenv fdt_high "0xffffffff"
setenv bootcmd "dnw  0xc0008000; fatload mmc 0:1 0x42000000 uInitrd; bootm 0xc0008000 0x42000000"
setenv bootargs "console=tty1 console=ttySAC1,115200n8 root=UUID=e139ce78-9841-40fe-8823-96a304a09859 rootwait ro mem=1023M"
boot


4.3 boot.scr (printenv)
 

baudrate=115200
bootargs=fb_x_res=1280 fb_y_res=720 hdmi_phy_res=720 
bootcmd= mmc rescan 0:1; mmc rescan 0:2;  if run loadbootscript_1;     then run bootscript;  else     if run loadbootscript_2;         then run bootscript;     else         run default_bootcmd;     fi ; fi ; 
bootdelay=1
bootscript=source 40008000
default_bootcmd=echo >>> Run Default Bootcmd <<<;movi read kernel 0 40008000;movi read rootfs 0 41000000 100000;bootm 40008000 41000000
ethaddr=00:40:5c:26:0a:5b
gatewayip=192.168.0.1
ipaddr=192.168.0.20
loadbootscript_1=echo >>> Load Boot Script from mmc 0:1 <<<;fatload mmc 0:1 40008000 boot.scr
loadbootscript_2=echo >>> Load Boot Script from mmc 0:2 <<<;fatload mmc 0:2 40008000 boot.scr
netmask=255.255.255.0
serverip=192.168.0.10


5. mkimage 의 Image header 제거 

mkimage를 사용할 경우 헤더가  64byte 가 사용이 되며, 이는  boot시 사용이 된다. 그리고, 이와 같은 이미지가 필요 없을 경우 아래와 같이 제거 한다.
mkimage를 사용하는 것은 ramdisk, kernel image, boot.scr이 있다.

dd if=image of=recovered file bs=64 skip=1

RAMDISK의 경우 아래와 같이 mkimage를 제거하고, 압축을 풀고 카피한 다음 분석가능

gunzip initrd.gz
mkdir init
cd init
cpio -i < ../initrd


  https://wiki.linaro.org/MichaelHope/Sandbox/DebuggingOnInitrd