uboot 命令列操作簡介

%http://blog.csdn.net/ghostyu/article/details/6968681
%http://www.denx.de/wiki/view/DULG/Manual

目的：了解 uboot 的命令列操作方式

uboot 是一套廣泛使用在嵌入式系統上之 bootloader，要順利的使用 uboot，必須對其命令列操作方式有所了解，如此一來當 uboot 在開機時發生錯誤的話，才能夠自己一一針對故障進行排除。底下我們將針對 uboot 的指令作概略的說明：

help -> 呼叫可使用之指令，如底下所示：

?       - alias for 'help'
askenv  - get environment variables from stdin
base    - print or set address offset
bdinfo  - print Board Info structure
boot    - boot default, i.e., run 'bootcmd'
bootd   - boot default, i.e., run 'bootcmd'
bootm   - boot application image from memory
bootp   - boot image via network using BOOTP/TFTP protocol
bootz   - boot Linux zImage image from memory
chpart  - change active partition
cmp     - memory compare
coninfo - print console devices and information
cp      - memory copy
crc32   - checksum calculation
dcache  - enable or disable data cache
dhcp    - boot image via network using DHCP/TFTP protocol
echo    - echo args to console
editenv - edit environment variable
env     - environment handling commands
exit    - exit script
ext2load- load binary file from a Ext2 filesystem
ext2ls  - list files in a directory (default /)
false   - do nothing, unsuccessfully
fatinfo - print information about filesystem
fatload - load binary file from a dos filesystem
fatls   - list files in a directory (default /)
fdt     - flattened device tree utility commands
go      - start application at address 'addr'
gpio    - input/set/clear/toggle gpio pins
help    - print command description/usage
i2c     - I2C sub-system
icache  - enable or disable instruction cache
imxtract- extract a part of a multi-image
itest   - return true/false on integer compare
led     - [0|1|green|all] [on|off|toggle]
load    - load binary file from a filesystem
loadb   - load binary file over serial line (kermit mode)
loads   - load S-Record file over serial line
loadx   - load binary file over serial line (xmodem mode)
loady   - load binary file over serial line (ymodem mode)
loop    - infinite loop on address range
ls      - list files in a directory (default /)
md      - memory display
mm      - memory modify (auto-incrementing address)
mmc     - MMC sub system
mmcinfo - display MMC info
mtdparts- define flash/nand partitions
mw      - memory write (fill)
nand    - NAND sub-system
nandecc - switch OMAP3 NAND ECC calculation algorithm
nboot   - boot from NAND device
nfs     - boot image via network using NFS protocol
nm      - memory modify (constant address)
ping    - send ICMP ECHO_REQUEST to network host
printenv- print environment variables
reset   - Perform RESET of the CPU
run     - run commands in an environment variable
saveenv - save environment variables to persistent storage
setenv  - set environment variables
setexpr - set environment variable as the result of eval expression
showvar - print local hushshell variables
sleep   - delay execution for some time
source  - run script from memory
test    - minimal test like /bin/sh
tftpboot- boot image via network using TFTP protocol
true    - do nothing, successfully
usb     - USB sub-system
usbboot - boot from USB device
version - print monitor, compiler and linker version

version(v) -> 顯示目前 u-boot 版本，如底下所示：

U-Boot 2013.10 (Nov 15 2013 - 09:58:56)
arm-linux-gnueabi-gcc (Debian 4.4.6-14) 4.4.6
GNU ld (GNU Binutils for Debian) 2.22

usb start -> 啟動 usb 功能，其畫面如下所示：

(Re)start USB...
USB0:   ULPI: ulpi_reset: failed writing reset bit
ULPI: ulpi_reset: failed writing reset bit
USB EHCI 0.00
scanning bus 0 for devices... 1 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
       scanning usb for ethernet devices... 0 Ethernet Device(s) found

usb info -> 觀看 usb 資訊，如底下所示：

1: Hub,  USB Revision 2.0
 - u-boot EHCI Host Controller
 - Class: Hub
 - PacketSize: 64  Configurations: 1
 - Vendor: 0x0000  Product 0x0000 Version 1.0
   Configuration: 1
   - Interfaces: 1 Self Powered 0mA
     Interface: 0
     - Alternate Setting 0, Endpoints: 1
     - Class Hub
     - Endpoint 1 In Interrupt MaxPacket 8 Interval 255ms


bdinfo -> 顯示目前板子資訊，如底下所示：

arch_number = 0x0000060A
boot_params = 0x80000100
DRAM bank   = 0x00000000
-> start    = 0x80000000
-> size     = 0x08000000
DRAM bank   = 0x00000001
-> start    = 0x88000000
-> size     = 0x08000000
eth0name    = usb_ether
ethaddr     = (not set)
current eth = usb_ether
ip_addr     = <NULL>
baudrate    = 115200 bps
TLB addr    = 0x8FFF0000
relocaddr   = 0x8FF59000
reloc off   = 0x0FE59000
irq_sp      = 0x8FEF8F30
sp start    = 0x8FEF8F20


mmcinfo -> 顯示目前記憶卡資訊，如底下所示：

Device: OMAP SD/MMC
Manufacturer ID: aa
OEM: 5859
Name: QEMU!
Tran Speed: 25000000
Rd Block Len: 512
SD version 1.0
High Capacity: No
Capacity: 1 GiB
Bus Width: 4-bit

mmc -> 顯示記憶卡之相關操作指令，如下所示：

Usage:
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


mmclist -> 顯示目前的記憶卡，如底下所示：

OMAP SD/MMC: 0

mmc rescan -> 重新掃瞄目前板子上有幾張記憶卡

mmc part -> 顯示目前記憶卡上之分割區，如底下所示：

Partition Map for MMC device 0  --   Partition Type: DOS

Part    Start Sector    Num Sectors     UUID            Type
  1     2048            163840          bafb41f7-01     0b Boot
  2     165888          1931264         bafb41f7-02     83


此資訊可搭配之前分割之 sdcard.img 來比較，如下所示：

      Device Boot      Start         End      Blocks   Id  System
/dev/loop0p1   *        2048      165887       81920    b  W95 FAT32
/dev/loop0p2          165888     2097151      965632   83  Linux



fatinfo -> 觀看 FAT filesystem 資訊，其語法如下：

fatinfo <interface> [<dev[:part]>]

其中的 interface 是指儲存介面，而 dev:part 則是指其裝置及分割區編號


我們可以執行底下指令來觀看 sdcard.img 的 #1 分割區：

fatinfo mmc 0:1

其輸出如下：

Interface:  MMC
  Device 0: Vendor: Man 0000aa Snr adbeef00 Rev: 13.14 Prod: QEMU!
            Type: Removable Hard Disk
            Capacity: 1024.0 MB = 1.0 GB (2097152 x 512)
Filesystem: FAT16 "           "

fatls -> 列出 FAT 分割區之內容，其語法如下：

fatls <interface> [<dev[:part]>] [directory]

因此我們可以執行底下指令來觀看 FAT 檔案系統中之檔案：

fatls mmc 0:1

其輸出如下所示：

  2539176   uimage
    47164   mlo
  1622640   u-boot
   346280   u-boot.img
   346216   u-boot.bin
  2539112   zimage

6 file(s), 0 dir(s)

fatloat -> 載入 FAT 檔案系統中之檔案，其語法如下：

fatload <interface> [<dev[:part]>]  <addr> <filename> [bytes [pos]]

現在，我們要將編好的 Linux 核心載入至 ARM 的初始記憶體位置，也就是

0x80000000，我們應該要下底下指令：

fatload mmc 0:1 0x80000000 uImage

其輸出如下所示：

reading uImage
2539176 bytes read in 325 ms (7.5 MiB/s)

這個訊息告訴我們，uboot 已載入 Linux 核心，其檔名為 uImage，根據我們所下的
指令，這個核心被載入至 0x80000000 的位置。

bootm -> 從某個記憶體位置開機，以我們的例子來說，其開機位置為 0x80000000。

因此我們可以下底下指令來開機：

bootm 0x80000000