U-BOOT下使用bootm引导内核方法［转载］

喜欢ヅ旅行 2022-01-13 16:45 198阅读 0赞

注：  
u-boot 使用的是打上：  
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上keety大侠提供的补丁生成的u-boot-1.1.3

这段时间不断有人问我u-boot启动内核的问题，记得在上次提供的u-boot源码中提到了go的方案，不过其实u-boot本来有一种更好的方案： bootm  
花了不少时间，查看了论坛上不少的帖子，认真阅读了bootm的源码，终于使用bootm把内核给跑起来了， 现把解决方法介绍如下：

一、在开始之前先说明一下bootm相关的东西。

1、首先说明一下，S3C2410架构下的bootm只对sdram中的内核镜像文件进行操作(好像AT91架构提供了一段从flash复制内核镜像的代码，不过针对s3c2410架构就没有这段代码，虽然可以在u-boot下添加这段代码，不过好像这个用处不大)，所以请确保你的内核镜像下载到sdram 中，或者在bootcmd下把flash中的内核镜像复制到sdram中。

2、-a参数后是内核的运行地址，-e参数后是入口地址。  
  
3、  
1）如果我们没用mkp\_w\_picpath对内核进行处理的话，那直接把内核下载到0x30008000再运行就行，内核会自解压运行（不过内核运行需要一个tag来传递参数，而这个tag建议是由bootloader提供的，在u-boot下默认是由bootm命令建立的）。  
  
2）如果使用mkp\_w\_picpath生成内核镜像文件的话，会在内核的前头加上了64byte的信息，供建立tag之用。bootm命令会首先判断bootm xxxx 这个指定的地址xxxx是否与-a指定的加载地址相同。  
(1)如果不同的话会从这个地址开始提取出这个64byte的头部，对其进行分析，然后把去掉头部的内核复制到-a指定的load地址中去运行之  
(2)如果相同的话那就让其原封不同的放在那，但-e指定的入口地址会推后64byte，以跳过这64byte的头部。  
  
  
二、好，接着介绍使用mkp\_w\_picpath生成镜像文件并下载运行的方法。  
  
方法一、  
1、首先，用u-boot/tools/mkp\_w\_picpath这个工具为你的内核加上u-boot引导所需要的文件头，具体做法如下：  
\[root@localhost tftpboot\]\#mkp\_w\_picpath -n 'linux-2.6.14' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008000 -d zImage zImage.img  
Image Name: linux-2.6.14  
Created: Fri Jan 12 17:14:50 2007  
Image Type: ARM Linux Kernel Image (uncompressed)  
Data Size: 1262504 Bytes = 1232.91 kB = 1.20 MB  
Load Address: 0x30008000  
Entry Point: 0x30008000

这里解释一下参数的意义：  
\-A ==> set architecture to 'arch'  
\-O ==> set operating system to 'os'  
\-T ==> set p\_w\_picpath type to 'type'  
\-C ==> set compression type 'comp'  
\-a ==> set load address to 'addr' (hex)  
\-e ==> set entry point to 'ep' (hex)  
\-n ==> set p\_w\_picpath name to 'name'  
\-d ==> use p\_w\_picpath data from 'datafile'  
\-x ==> set XIP (execute in place)

2 、下载内核  
U-Boot 1.1.3 (Jan 12 2007 - 16:16:36)

U-Boot code: 33F80000 -> 33F9BAC0 BSS: -> 33F9FBAC  
RAM Configuration:  
Bank \#0: 30000000 64 MB  
Nor Flash: 512 kB  
Nand Flash: 64 MB  
In: serial  
Out: serial  
Err: serial  
Hit any key to stop autoboot: 0  
sbc2410=>tftp 0x31000000 zImage.img  
TFTP from server 192.168.1.115; our IP address is 192.168.1.128  
Filename 'zImage.img'.  
Load address: 0x31000000  
Loading: \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
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\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
done  
Bytes transferred = 1263324 (1346dc hex)  
  
3.运行

sbc2410=>bootm 0x31000000  
\#\# Booting p\_w\_picpath at 31000000 ...  
Image Name: linun-2.6.14  
Image Type: ARM Linux Kernel Image (uncompressed)  
Data Size: 1263260 Bytes = 1.2 MB  
Load Address: 30008000  
Entry Point: 30008000  
Verifying Checksum ... OK  
OK

Starting kernel ...

Uncompressing Linux.............................................................Linux version 2.6.14 (root@luofuchong) (gcc version 3.4.1) \#21 Fri Oct 20 17:206CPU: ARM920Tid(wb) \[41129200\] revision 0 (ARMv4T)  
Machine: SMDK2410  
Memory policy: ECC disabled, Data cache writeback  
CPU S3C2410A (id 0x32410002)  
S3C2410: core 202.800 MHz, memory 101.400 MHz, peripheral 50.700 MHz  
S3C2410 Clocks, (c) 2004 Simtec Electronics  
CLOCK: Slow mode (1.500 MHz), fast, MPLL on, UPLL on  
USB Control, (c) 2006 sbc2410  
CPU0: D VIVT write-back cache  
CPU0: I cache: 16384 bytes, associativity 64, 32 byte lines, 8 sets  
CPU0: D cache: 16384 bytes, associativity 64, 32 byte lines, 8 sets  
Built 1 zonelists  
Kernel command line: console=ttySAC0 root=/dev/nfs nfsroot=192.168.1.115:/frien"irq: clearing subpending status 00000002  
PID hash table entries: 512 (order: 9, 8192 bytes)  
timer tcon=00500000, tcnt a509, tcfg 00000200,00000000, usec 00001e4c  
Console: colour dummy device 80x30  
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)  
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)  
Memory: 64MB = 64MB total  
Memory: 62208KB available (1924K code, 529K data, 108K init)  
Mount-cache hash table entries: 512  
CPU: Testing write buffer coherency: ok  
softlockup thread 0 started up.  
NET: Registered protocol family 16  
S3C2410: Initialising architecture  
SCSI subsystem initialized  
usbcore: registered new driver usbfs  
usbcore: registered new driver hub  
S3C2410 DMA Driver, (c) 2003-2004 Simtec Electronics  
DMA channel 0 at c4800000, irq 33  
DMA channel 1 at c4800040, irq 34  
DMA channel 2 at c4800080, irq 35  
DMA channel 3 at c48000c0, irq 36  
NetWinder Floating Point Emulator V0.97 (double precision)  
devfs: 2004-01-31 Richard Gooch (rgooch@atnf.csiro.au)  
devfs: devfs\_debug: 0x0  
devfs: boot\_options: 0x1  
yaffs Oct 18 2006 12:39:51 Installing.  
Console: switching to colour frame buffer device 30x40  
fb0: s3c2410fb frame buffer device  
fb1: Virtual frame buffer device, using 1024K of video memory  
led driver initialized  
s3c2410 buttons successfully loaded  
s3c2410\_serial0 at MMIO 0x50000000 (irq = 70) is a S3C2410  
s3c2410\_serial1 at MMIO 0x50004000 (irq = 73) is a S3C2410  
s3c2410\_serial2 at MMIO 0x50008000 (irq = 76) is a S3C2410  
io scheduler noop registered  
io scheduler anticipatory registered  
io scheduler deadline registered  
io scheduler cfq registered  
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize  
usbcore: registered new driver ub  
Cirrus Logic CS8900A driver for Linux (Modified for SMDK2410)  
eth0: CS8900A rev E at 0xe0000300 irq=53, no eeprom , addr: 08: 0:3E:26:0A:5B  
S3C24XX NAND Driver, (c) 2004 Simtec Electronics  
s3c2410-nand: mapped registers at c4980000  
s3c2410-nand: timing: Tacls 10ns, Twrph0 30ns, Twrph1 10ns  
NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bi)Scanning device for bad blocks  
Bad eraseblock 1884 at 0x01d70000  
Creating 4 MTD partitions on "NAND 64MiB 3,3V 8-bit":  
0x00000000-0x00020000 : "vivi"  
0x00020000-0x00030000 : "param"  
0x00030000-0x00200000 : "kernel"  
0x00200000-0x04000000 : "root"  
usbmon: debugfs is not available  
s3c2410-ohci s3c2410-ohci: S3C24XX OHCI  
s3c2410-ohci s3c2410-ohci: new USB bus registered, assigned bus number 1  
s3c2410-ohci s3c2410-ohci: irq 42, io mem 0x49000000  
hub 1-0:1.0: USB hub found  
hub 1-0:1.0: 2 ports detected  
Initializing USB Mass Storage driver...  
usbcore: registered new driver usb-storage  
USB Mass Storage support registered.  
usbcore: registered new driver usbmouse  
drivers/usb/input/usbmouse.c: v1.6:USB HID Boot Protocol mouse driver  
mice: PS/2 mouse device common for all mice  
s3c2410 TouchScreen successfully loaded  
UDA1341 audio driver initialized  
NET: Registered protocol family 2  
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)  
TCP established hash table entries: 4096 (order: 2, 16384 bytes)  
TCP bind hash table entries: 4096 (order: 2, 16384 bytes)  
TCP: Hash tables configured (established 4096 bind 4096)  
TCP reno registered  
TCP bic registered  
NET: Registered protocol family 1  
IP-Config: Complete:  
device=eth0, addr=192.168.1.128, mask=255.255.255.0, gw=192.168.1.1,  
host=luofuchong, domain=, nis-domain=(none),  
bootserver=192.168.1.1, rootserver=192.168.1.115, rootpath=  
Looking up port of RPC 100003/2 on 192.168.1.115  
Looking up port of RPC 100005/1 on 192.168.1.115  
VFS: Mounted root (nfs filesystem).  
Mounted devfs on /dev  
Freeing init memory: 108K  
init started: BusyBox v1.1.3 (2006.09.20-14:52+0000) multi-call binary  
Starting pid 696, console /dev/tts/0: '/etc/init.d/rcS'

Please press Enter to activate this console.

方法二、  
1、首先，用u-boot/tools/mkp\_w\_picpath这个工具为你的内核加上u-boot引导所需要的文件头，具体做法如下：  
\[root@localhost tftpboot\]\#mkp\_w\_picpath -n 'linux-2.6.14' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008040 -d zImage zImage.img  
Image Name: linux-2.6.14  
Created: Fri Jan 12 17:14:50 2007  
Image Type: ARM Linux Kernel Image (uncompressed)  
Data Size: 1262504 Bytes = 1232.91 kB = 1.20 MB  
Load Address: 0x30008000  
Entry Point: 0x30008040

2 、下载内核  
U-Boot 1.1.3 (Jan 12 2007 - 16:16:36)

U-Boot code: 33F80000 -> 33F9BAC0 BSS: -> 33F9FBAC  
RAM Configuration:  
Bank \#0: 30000000 64 MB  
Nor Flash: 512 kB  
Nand Flash: 64 MB  
In: serial  
Out: serial  
Err: serial  
Hit any key to stop autoboot: 0  
sbc2410=>tftp 0x30008000 zImage.img  
TFTP from server 192.168.1.115; our IP address is 192.168.1.128  
Filename 'zImage.img'.  
Load address: 0x30008000  
Loading: \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
done  
Bytes transferred = 1263324 (1346dc hex)  
  
3.运行

sbc2410=>bootm 0x30008000  
\#\# Booting p\_w\_picpath at 30008000 ...  
Image Name: linux-2.6.14  
Image Type: ARM Linux Kernel Image (uncompressed)  
Data Size: 1261056 Bytes = 1.2 MB  
Load Address: 30008000  
Entry Point: 30008040  
Verifying Checksum ... OK  
XIP Kernel Image ... OK

内核启动信息省。。。。

三、固化  
  
如果你想把镜像文件写入flash，每次开机后让u-boot帮你复制到sdram中，再使用bootm命令引导的话，可以按照这样操作：  
sbc2410=>tftp 0x30008000 zImage.img  
TFTP from server 192.168.1.115; our IP address is 192.168.1.128  
Filename 'zImage.img'.  
Load address: 0x30008000  
Loading: \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
done  
Bytes transferred = 1263324 (1346dc hex)  
sbc2410=>nand erase 0x30000 0x1d0000

NAND erase: device 0 offset 196608, size 1900544 ... OK  
sbc2410=>nand write 0x30008000 0x30000 0x1d0000

NAND write: device 0 offset 196608, size 1900544 ... 1900544 bytes written: OK

设置u-boot启动命令：  
1、针对方法一：  
sbc2410=>setenv bootcmd nand read 0x31000000 0x30000 0x1d0000\\;bootm 0x31000000  
sbc2410=>saveenv  
Saving Environment to NAND...  
Erasing Nand...Writing to Nand... done  
2、针对方法二：  
sbc2410=>setenv bootcmd nand read 0x30008000 0x30000 0x1d0000\\;bootm 0x30008000  
sbc2410=>saveenv  
Saving Environment to NAND...  
Erasing Nand...Writing to Nand... done  
  
sbc2410=>reset  
启动信息略。。。。

转载于:https://blog.51cto.com/lion3875/532278

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