从skyeye学习arm（文件系统篇）
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本来这个系列的blog是在春节前准备的，因为过年耽误了一段时间。没有关系，今天我们继续补上。前面，我们说到了uboot、linux。因此要想系统正常可以运行起来，就差一个文件系统了。文件系统简单来说就是提前准备的一些文件打包压缩起来，内容通常有busybox生成的执行文件、dev node文件、etc脚本文件，准备好后用工具压缩一下就可以了。
关于文件系统，这里不打算说太多，因为我觉得这不是重点，我们应该把经历放在需要的地方去。长话短说，如果大家想有一份文件系统，有两种方法，
1） 直接使用别人制作好的文件系统，比如说我们可以使用skyeye-testsuite-1.2.5.tar.bz2提供的initrd.img，具体的位置在linux/s3c2410/s3c2410x-2.6.14目录下。
2） 自己制作一份文件系统，具体的制作方法可以参照这里，http://www.cnblogs.com/guocai/archive/2012/02/21/2362377.html.
在我看来，制作文件系统不是主要的，了解怎么使用这才比较重要。有了上面的文件系统，我们就可以加载了。skyeye文件如下，
# skyeye config file for S3C2410X cpu: arm920t mach: s3c2410x # physical memory mem_bank: map=M, type=RW, addr=0x00000000, size=0x10000000, file=../u-boot-1.3.2/u-boot mem_bank: map=M, type=RW, addr=0x30000000, size=0x04000000, mem_bank: map=M, type=RW, addr=0xc0000000, size=0x00800000, file=../linux-2.6.14/vmlinux mem_bank: map=M, type=RW, addr=0xc0800000, size=0x00800000, file=./initrd.img mem_bank: map=M, type=RW, addr=0xc1000000, size=0x01000000 # all peripherals I/O mapping area mem_bank: map=I, type=RW, addr=0x48000000, size=0x20000000 mem_bank: map=I, type=RW, addr=0x19000300, size=0x00000020 net: type=cs8900a, base=0x19000300, size=0x20,int=9, mac=0:4:3:2:1:f, ethmod=tuntap, hostip=10.0.0.1 lcd: type=s3c2410x, mod=gtk #dbct:state=on如果我们想快速加载文件系统，可以直接越过u-boot，输入skyeye -e ../linux-2.6.14/vmlinux即可，效果如下，
root@hp-6531s:~/Desktop/env/arm_linux_2.6.14$ skyeye -e ../linux-2.6.14/vmlinux
Your elf file is little endian.
arch: arm
cpu info: armv4, arm920t, 41009200, ff00fff0, 2
mach info: name s3c2410x, mach_init addr 0x806dc30
ethmod num=1, mac addr=0:4:3:2:1:f, hostip=10.0.0.1
failed to setup_module (name:net, type:cs8900a)
tapif_init: icotl TUNSETIFF erroruart_mod:0, desc_in:, desc_out:, converter:
SKYEYE: use arm920t mmu ops
Loaded RAM ../u-boot-1.3.2/u-boot
Loaded RAM ../linux-2.6.14/vmlinux
Loaded RAM ./initrd.img
start addr is set to 0xc0008000 by exec file.
Linux version 2.6.14 (realsil@hp-6531s) (gcc version 3.4.1) #5 Thu Feb 20 15:00:09 CST 2014
CPU: ARM920Tid(wb) [41009200] revision 0 (ARMvundefined/unknown)
Machine: SMDK2410
Warning: bad configuration page, trying to continue
Memory policy: ECC disabled, Data cache writeback
CPU S3C2410 (id 0x32410000)
S3C2410: core 62.400 MHz, memory 62.400 MHz, peripheral 62.400 MHz
S3C2410 Clocks, (c) 2004 Simtec Electronics
CLOCK: Slow mode (1.500 MHz), fast, MPLL on, UPLL on
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: mem=32M console=ttySAC0 root=/dev/ram initrd=0xc0800000,0x00800000 ramdisk_size=8192 rw
PID hash table entries: 256 (order: 8, 4096 bytes)
timer tcon=00000000, tcnt cb1f, tcfg 00000200,00000000, usec 0000189e
Console: colour dummy device 80x30
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 32MB = 32MB total
Memory: 22320KB available (1469K code, 271K data, 92K init)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
checking if image is initramfs...it isn't (bad gzip magic numbers); looks like an initrd
softlockup thread 0 started up.
Freeing initrd memory: 8192K
NET: Registered protocol family 16
S3C2410: Initialising architecture
Console: switching to colour frame buffer device 80x25
fb0: Virtual frame buffer device, using 1024K of video memory
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 8192K size 1024 blocksize
mice: PS/2 mouse device common for all mice
NET: Registered protocol family 2
IP route cache hash table entries: 512 (order: -1, 2048 bytes)
TCP established hash table entries: 2048 (order: 1, 8192 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
TCP reno registered
TCP bic registered
NET: Registered protocol family 1
RAMDISK: ext2 filesystem found at block 0
RAMDISK: Loading 2048KiB [1 disk] into ram disk... done.
VFS: Mounted root (ext2 filesystem).
Freeing init memory: 92K
init started: BusyBox v1.4.1 (2007-02-10 01:19:06 CST) multi-call binary
Starting pid 16, console /dev/console: '/etc/init.d/rcS'
ifconfig: SIOCSIFADDR: No such device
Welcome to
_ _____ __ __ _ _
/ \ / __ \ / \_/ \ | | |_|
/ _ \ | | | | / /\ /\ \ | | _ ____ _ _ _ _
/ /_\ \ | |__| | / / \_/ \ \| | | | _ \| | | |\ \/ /
/ /___\ \ | |__\ \ | | | || |___ | | |_| | |_| |/ \
/_/ \_\| | \_\|_| |_||_____||_|_| |_|\____|\_/\_/
ARMLinux for Skyeye
For further information please check:
http://www.skyeye.org/
BusyBox v1.4.1 (2007-02-10 01:19:06 CST) Built-in shell (ash)
Enter 'help' for a list of built-in commands.
/bin/ash: can't access tty; job control turned off
/ $
/ $ ls
bin home linuxrc root usr
dev initrd lost+found sbin var
etc lib proc tmp
/ $
上面加载的很顺利，如果我们想从uboot加载呢，可以这么做，首先skyeye -e ../u-boot-1.3.2/u-boot，如下所示，
root@hp-6531s:~/Desktop/env/arm_linux_2.6.14$ skyeye -e ../u-boot-1.3.2/u-boot Your elf file is little endian. arch: arm cpu info: armv4, arm920t, 41009200, ff00fff0, 2 mach info: name s3c2410x, mach_init addr 0x806dc30 ethmod num=1, mac addr=0:4:3:2:1:f, hostip=10.0.0.1 failed to setup_module (name:net, type:cs8900a) tapif_init: icotl TUNSETIFF erroruart_mod:0, desc_in:, desc_out:, converter: SKYEYE: use arm920t mmu ops Loaded RAM ../u-boot-1.3.2/u-boot Loaded RAM ../linux-2.6.14/vmlinux Loaded RAM ./initrd.img start addr is set to 0x33f80000 by exec file. ERROR: s3c2410x_io_write_word(0x4c000000) = 0x00ffffff ERROR: s3c2410x_io_write_word(0x4c000008) = 0x00048032 U-Boot 1.3.2 (Jan 27 2014 - 15:32:01) DRAM: 64 MB Flash: 512 kB *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial ERROR: s3c2410x_io_write_word(0x1900030a) = 0x00000000 SMDK2410 # bootelf 0xc0000000待uboot启动后，直接输入bootelf 0xc0000000，就可以得到和上面一样的打印信息了。当然如果对booelf不放心，可以直接输入go 0xc0008000，效果是一样的。
root@hp-6531s:~/Desktop/env/arm_linux_2.6.14$ skyeye -e ../u-boot-1.3.2/u-boot Your elf file is little endian. arch: arm cpu info: armv4, arm920t, 41009200, ff00fff0, 2 mach info: name s3c2410x, mach_init addr 0x806dc30 ethmod num=1, mac addr=0:4:3:2:1:f, hostip=10.0.0.1 failed to setup_module (name:net, type:cs8900a) tapif_init: icotl TUNSETIFF erroruart_mod:0, desc_in:, desc_out:, converter: SKYEYE: use arm920t mmu ops Loaded RAM ../u-boot-1.3.2/u-boot Loaded RAM ../linux-2.6.14/vmlinux Loaded RAM ./initrd.img start addr is set to 0x33f80000 by exec file. ERROR: s3c2410x_io_write_word(0x4c000000) = 0x00ffffff ERROR: s3c2410x_io_write_word(0x4c000008) = 0x00048032 U-Boot 1.3.2 (Jan 27 2014 - 15:32:01) DRAM: 64 MB Flash: 512 kB *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial ERROR: s3c2410x_io_write_word(0x1900030a) = 0x00000000 SMDK2410 # go 0xc0008000如果对上面效果还算满意的朋友，可以去好好试一试。