下载与烧写
使用U-boot将映像文件烧写到板上的Flash，一般步骤是： （1）通过网络、串口、U盘、SD卡等方式将文件传输到SDRAM； （2）使用Nand Flash或Nor Flash相关的读写命令将SDRAM中的数据烧入Flash。
下面是烧写范例： 如果使用 SD卡和U盘形式更新U-boot，那么首先SD卡和U盘中必须有FAT32文件系统，并在里面存放了u-boot.bin 文件。 1) 通过SD卡烧入Nand Flash：
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[[email protected]]# mmc init mmc: Probing for SDHC ... mmc: SD 2.0 or later card found trying to detect SD Card... Manufacturer: 0x00, OEM "Product name: " ", revision 0.0 Serial number: 7864775 Manufacturing date: 11/2006 CRC: 0x4f, b0 = 1 READ_BL_LEN=6, C_SIZE_MULT=7, C_SIZE=4095 size = 0 SD Card detected RCA: 0x2 type: SD mmc1 is available [[email protected]]# fatload mmc 1 0x30008000 u-boot.bin reading u-boot.bin 256220 bytes read [[email protected]]# nand erase 0 0x40000 NAND erase: device 0 offset 0x0, size 0x40000 Erasing at 0x2000000000004 -- 0% complete. OK [[email protected]]# nand write 0x30008000 0 0x40000 NAND write: device 0 offset 0x0, size 0x40000 Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK |
2) 通过U盘烧入Nor Flash：
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[[email protected]]# usb start (Re)start USB... USB: scanning bus for devices... 2 USB Device(s) found scanning bus for storage devices... 1 Storage Device(s) found [[email protected]]# usb storage Device 0: Vendor: Kingston Rev: PMAP Prod: DT 101 II Type: Removable Hard Disk Capacity: 3875.0 MB = 3.7 GB (7936000 x 512) [[email protected]]# usb part 0 print_part of 0 Partition Map for USB device 0 -- Partition Type: DOS Partition Start Sector Num Sectors Type 4 63 7935937 c [[email protected]]# fatload usb 0:4 0x30008000 u-boot.bin reading u-boot.bin ........................ 256220 bytes read [[email protected]]# protect off all Un-Protect Flash Bank # 1 [[email protected]]# erase 0x0 0x3ffff Erasing sector 0 ... ok. Erasing sector 1 ... ok. Erasing sector 2 ... ok. Erasing sector 3 ... ok. Erased 4 sectors [[email protected]]# cp.b 0x30008000 0x0 0x3ffff Copy to Flash... done |
3) 通过TFTP服务烧入Nand Flash：
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[[email protected]]# tftpboot 30008000 192.168.1.100:u-boot.bin dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:08:11:18:12:27 operating at 100M full duplex mode Using dm9000 device TFTP from server 192.168.1.100; our IP address is 192.168.1.101 Filename ‘u-boot.bin‘. Load address: 0x30008000 Loading: T ################## done Bytes transferred = 256220 (3e8dc hex) [[email protected]]# nand erase 0 0x40000 NAND erase: device 0 offset 0x0, size 0x40000 Erasing at 0x2000000000004 -- 0% complete. OK [[email protected]]# nand write 0x30008000 0 0x40000 NAND write: device 0 offset 0x0, size 0x40000 Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK |
4) 通过NFS 服务烧入Nand Flash：
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[[email protected]]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/u-boot.bin dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:08:11:18:12:27 operating at 100M full duplex mode Using dm9000 device File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101 Filename ‘/home/tekkaman/development/share/u-boot.bin‘. Load address: 0x30008000 Loading: ################################################### done Bytes transferred = 256220 (3e8dc hex) [[email protected]]# nand erase 0 0x40000 NAND erase: device 0 offset 0x0, size 0x40000 Erasing at 0x2000000000004 -- 0% complete. OK [[email protected]]# nand write 0x30008000 0 0x40000 NAND write: device 0 offset 0x0, size 0x40000 Writing at 0x2000000020000 -- 100% is complete. 262144 bytes written: OK |
内核引导
内核的引导步骤如下： （1）用U-boot的mkimage工具处理内核映像zImage。 （2）通过网络、串口、U盘、SD卡等方式将处理过的内核映像传输到SDRAM的一定位置（一般使用0x30008000） （3）然后使用”bootm"等内核引导命令来启动内核。
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为什么要用U-boot的mkimage工具处理内核映像zImage？ 因为在用bootm命令引导内核的时候，bootm需要读取一个64字节的文件头，来获取这个内核映象所针对的CPU体系结构、OS、加载到内存中的位置、在内存中入口点的位置以及映象名等等信息。这样bootm才能为OS设置好启动环境，并跳入内核映象的入口点。而mkimage就是添加这个文件头的专用工具。具体的实现请看U-boot中bootm的源码和mkimage的源码。 |
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mkimage工具的使用： 参数说明： -A指定CPU的体系结构，可用值有：alpha、arm 、x86、ia64、mips、mips64、ppc 、s390、sh、sparc 、sparc64、m68k等 -O指定操作系统类型，可用值有：openbsd、netbsd、freebsd、4_4bsd、linux、svr4、esix、solaris、irix、sco、dell、ncr、lynxos、vxworks、psos、qnx、u-boot、rtems、artos -T指定映象类型，可用值有：standalone、kernel、ramdisk、multi、firmware、script、filesystem -C指定映象压缩方式，可用值有： none 不压缩(一般使用这个，因为zImage是已经被bzip2压缩过的自解压内核) gzip 用gzip的压缩方式 bzip2 用bzip2的压缩方式 -a指定映象在内存中的加载地址，映象下载到内存中时，要按照用mkimage制作映象时，这个参数所指定的地址值来下载 -e 指定映象运行的入口点地址，这个地址就是-a参数指定的值加上0x40（因为前面有个mkimage添加的0x40个字节的头） -n 指定映象名 -d指定制作映象的源文件 以下是制作内核映像的命令示例： mkimage -n ‘tekkaman‘ -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008040 -d zImage zImage.img |
以下是使用范例： 1) 通过SD卡引导内核： 首先SD卡中必须有FAT32文件系统，并在里面存放了处理过的内核映像文件。
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[[email protected]]# mmc init mmc: Probing for SDHC ... mmc: SD 2.0 or later card found trying to detect SD Card... Manufacturer: 0x00, OEM "Product name: " ", revision 0.0 Serial number: 7864775 Manufacturing date: 11/2006 CRC: 0x4f, b0 = 1 READ_BL_LEN=6, C_SIZE_MULT=7, C_SIZE=4095 size = 0 SD Card detected RCA: 0x2 type: SD mmc1 is available [[email protected]]# fatload mmc 1 30008000 zImage.img reading zImage.img 2277540 bytes read [[email protected]]# bootm 30008000 ## Booting kernel from Legacy Image at 30008000 ... Image Name: tekkaman Created: 2010-03-29 12:59:51 UTC Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 2277476 Bytes = 2.2 MB Load Address: 30008000 Entry Point: 30008040 Verifying Checksum ... OK XIP Kernel Image ... OK OK Starting kernel ... Uncompressing Linux... done, booting the kernel. Linux version 2.6.33.1 ([email protected]) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 CPU: VIVT data cache, VIVT instruction cache Machine: MINI2440 （略） |
2) 通过TFTP服务引导内核:
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[[email protected]]# tftpboot 0x30008000 192.168.1.100:zImage.img dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:08:11:18:12:27 operating at 100M full duplex mode Using dm9000 device TFTP from server 192.168.1.100; our IP address is 192.168.1.101 Filename ‘zImage.img‘. Load address: 0x30008000 Loading: T ################################################################# ################################################################# ########################## done Bytes transferred = 2277540 (22c0a4 hex) [[email protected]]# bootm 30008000 ## Booting kernel from Legacy Image at 30008000 ... Image Name: tekkaman Created: 2010-03-29 12:59:51 UTC Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 2277476 Bytes = 2.2 MB Load Address: 30008000 Entry Point: 30008040 Verifying Checksum ... OK XIP Kernel Image ... OK OK Starting kernel ... Uncompressing Linux... done, booting the kernel. Linux version 2.6.33.1 ([email protected]) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 CPU: VIVT data cache, VIVT instruction cache Machine: MINI2440 （略） |
3) 通过NFS服务引导内核：
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[[email protected]]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/zImage.img dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:08:11:18:12:27 operating at 100M full duplex mode Using dm9000 device File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101 Filename ‘/home/tekkaman/development/share/zImage.img‘. Load address: 0x30008000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ####################################################### done Bytes transferred = 2277540 (22c0a4 hex) [[email protected]]# bootm 30008000 ## Booting kernel from Legacy Image at 30008000 ... Image Name: tekkaman Created: 2010-03-29 12:59:51 UTC Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 2277476 Bytes = 2.2 MB Load Address: 30008000 Entry Point: 30008040 Verifying Checksum ... OK XIP Kernel Image ... OK OK Starting kernel ... Uncompressing Linux... done, booting the kernel. Linux version 2.6.33.1 ([email protected]) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 CPU: VIVT data cache, VIVT instruction cache Machine: MINI2440 （略） |
4) 通过Nand Flash引导内核： 首先要将处理过的内核映像文件烧入Nand Flash的一定位置（由内核分区表决定）。以后每次启动时用Nand Flash的读取命令先将这个内核映像文件读到内存的一定位置（由制作内核映像时的-a参数决定），再使用bootm命令引导内核。
内核映像文件的烧入：
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[[email protected]]# nfs 30008000 192.168.1.100:/home/tekkaman/development/share/zImage.img dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:08:11:18:12:27 operating at 100M full duplex mode Using dm9000 device File transfer via NFS from server 192.168.1.100; our IP address is 192.168.1.101 Filename ‘/home/tekkaman/development/share/zImage.img‘. Load address: 0x30008000 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ####################################################### done Bytes transferred = 2277540 (22c0a4 hex) [[email protected]]# nand erase 0x80000 0x300000 NAND erase: device 0 offset 0x80000, size 0x300000 Erasing at 0x36000001800000 -- 0% complete. OK [[email protected]]# nand write 30008000 0x80000 300000 NAND write: device 0 offset 0x80000, size 0x300000 Writing at 0x36000000020000 -- 100% is complete. 3145728 bytes written: OK |
内核引导:
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[[email protected]]# nand read 30008000 0x80000 300000 NAND read: device 0 offset 0x80000, size 0x300000 3145728 bytes read: OK [[email protected]]# bootm 30008000 ## Booting kernel from Legacy Image at 30008000 ... Image Name: tekkaman Created: 2010-03-29 12:59:51 UTC Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 2277476 Bytes = 2.2 MB Load Address: 30008000 Entry Point: 30008040 Verifying Checksum ... OK XIP Kernel Image ... OK OK Starting kernel ... Uncompressing Linux... done, booting the kernel. Linux version 2.6.33.1 ([email protected]) (gcc version 4.3.2 (crosstool-NG-1.6.1-tekkaman) ) #5 Mon Mar 29 20:58:50 CST 2010 CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c0007177 CPU: VIVT data cache, VIVT instruction cache Machine: MINI2440 （略） |