openwrt生成固件firmware过程
https://blog.csdn.net/viewsky11/article/details/53097672
由于想看看生成各个文件系统格式文件的过程，所以在Target Images中把ext4/jffs2/squashfs都打上了，实际上最后固件使用的文件系统是squashfs+jffs2
Target Images —>
[*] ext4 —>
[*] jffs2 | |
[*] squashfs —>
[*] GZip images
* Image Options *
(48) Root filesystem partition size (in MB)
[ ] Include kernel in root filesystem —-
[ ] Include DTB in root filesystem
用make V=s编译，看最后一段log，就是生成固件和文件系统的过程，下面是log并作了注释
cp $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux.elf $cc/bin/ramips/openwrt-ramips-mt7620-vmlinux.elf
cp $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux $cc/bin/ramips/openwrt-ramips-mt7620-vmlinux.bin
#内核文件用lzma压缩，生成vmlinux.bin.lzma
$cc/staging_dir/host/bin/lzma e $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux -lc1 -lp2 -pb2 $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux.bin.lzma
#用mkimage命令根据vmlinux.bin.lzma生成uImage.lzma
LZMA 4.65 : Igor Pavlov : Public domain : 2009-02-03
mkimage -A mips -O linux -T kernel -C lzma -a 0x80000000 -e 0x80000000 -n "MIPS OpenWrt Linux-3.18.29" -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux.bin.lzma $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/uImage.lzma
Image Name: MIPS OpenWrt Linux-3.18.29
Created: Tue May 10 20:43:10 2016
Image Type: MIPS Linux Kernel Image (lzma compressed)
Data Size: 1137576 Bytes = 1110.91 kB = 1.08 MB
Load Address: 80000000
Entry Point: 80000000
#将生成的uImage.lzma复制成openwrt-ramips-mt7620-uImage.bin
cp $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/uImage.lzma $cc/bin/ramips/openwrt-ramips-mt7620-uImage.bin
#用mksquashfs4压缩文件系统squashfs
$cc/staging_dir/host/bin/mksquashfs4 $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.squashfs -nopad -noappend -root-owned -comp xz -Xpreset 9 -Xe -Xlc 0 -Xlp 2 -Xpb 2 -b 256k -p '/dev d 755 0 0' -p '/dev/console c 600 0 0 5 1' -processors 1
Parallel mksquashfs: Using 1 processor
Creating 4.0 filesystem on $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.squashfs, block size 262144.
Pseudo file "/dev" exists in source filesystem "$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips/dev".
Ignoring, exclude it (-e/-ef) to override.
[=============================================================================================================================================================-] 959/959 100%
Exportable Squashfs 4.0 filesystem, xz compressed, data block size 262144
compressed data, compressed metadata, compressed fragments, no xattrs
duplicates are removed
Filesystem size 4604.89 Kbytes (4.50 Mbytes)
29.59% of uncompressed filesystem size (15562.88 Kbytes)
Inode table size 9708 bytes (9.48 Kbytes)
23.48% of uncompressed inode table size (41347 bytes)
Directory table size 12216 bytes (11.93 Kbytes)
47.85% of uncompressed directory table size (25528 bytes)
Number of duplicate files found 17
Number of inodes 1247
Number of files 933
Number of fragments 30
Number of symbolic links 207
Number of device nodes 1
Number of fifo nodes 0
Number of socket nodes 0
Number of directories 106
Number of ids (unique uids + gids) 1
Number of uids 1
root (0)
Number of gids 1
root (0)
############squashfs文件系统生成成功###############
##开始生成jffs2-64k文件系统
$cc/staging_dir/host/bin/mkfs.jffs2 --little-endian --squash-uids -v -X rtime -X lzma --compression-mode=size -x zlib -D $cc/include/device_table.txt --pad -e 64KiB -o $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-64k -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips -v 2>&1 1>/dev/null | awk '/^.+$/'
Compression mode: size
Compressors:
none compr: 177 blocks (109257) decompr: 0 blocks
zlib (prio:80) - compr: 0 blocks (0/0) decompr: 0 blocks
lzma (prio:70) + compr: 4463 blocks (6551797/15742007) decompr: 0 blocks
rtime (prio:50) + compr: 10 blocks (5292/7660) decompr: 0 blocks
Compression errors: 0
echo -ne '\xde\xad\xc0\xde' >> $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-64k
##生成jffs2-128k文件系统
$cc/staging_dir/host/bin/mkfs.jffs2 --little-endian --squash-uids -v -X rtime -X lzma --compression-mode=size -x zlib -D $cc/include/device_table.txt --pad -e 128KiB -o $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-128k -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips -v 2>&1 1>/dev/null | awk '/^.+$/'
Compression mode: size
Compressors:
none compr: 126 blocks (63985) decompr: 0 blocks
zlib (prio:80) - compr: 0 blocks (0/0) decompr: 0 blocks
lzma (prio:70) + compr: 4463 blocks (6569958/15781501) decompr: 0 blocks
rtime (prio:50) + compr: 13 blocks (10252/13438) decompr: 0 blocks
Compression errors: 0
echo -ne '\xde\xad\xc0\xde' >> $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-128k
#生成ext4文件系统
$cc/staging_dir/host/bin/make_ext4fs -l 50331648 -b 4096 -i 6000 -m 0 -J $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.ext4 $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips/
Creating filesystem with parameters:
Size: 50331648
Block size: 4096
Blocks per group: 32768
Inodes per group: 6000
Inode size: 256
Journal blocks: 0
Label:
Blocks: 12288
Block groups: 1
Reserved blocks: 0
Reserved block group size: 7
Created filesystem with 1256/6000 inodes and 5051/12288 blocks
#生成两个jffs2文件系统的raw，但是没看到他怎么使用它
$cc/staging_dir/host/bin/mkfs.jffs2 --little-endian --squash-uids -v -X rtime -X lzma --compression-mode=size -x zlib -D $cc/include/device_table.txt -e 64KiB -o $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-64k-raw -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips -v 2>&1 1>/dev/null | awk '/^.+$/'
Compression mode: size
Compressors:
none compr: 177 blocks (109257) decompr: 0 blocks
zlib (prio:80) - compr: 0 blocks (0/0) decompr: 0 blocks
lzma (prio:70) + compr: 4463 blocks (6551797/15742007) decompr: 0 blocks
rtime (prio:50) + compr: 10 blocks (5292/7660) decompr: 0 blocks
Compression errors: 0
$cc/staging_dir/host/bin/mkfs.jffs2 --little-endian --squash-uids -v -X rtime -X lzma --compression-mode=size -x zlib -D $cc/include/device_table.txt -e 128KiB -o $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-128k-raw -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips -v 2>&1 1>/dev/null | awk '/^.+$/'
Compression mode: size
Compressors:
none compr: 126 blocks (63985) decompr: 0 blocks
zlib (prio:80) - compr: 0 blocks (0/0) decompr: 0 blocks
lzma (prio:70) + compr: 4463 blocks (6569958/15781501) decompr: 0 blocks
rtime (prio:50) + compr: 13 blocks (10252/13438) decompr: 0 blocks
Compression errors: 0
#用dd生成最终的squashfs文件系统
dd if=$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.squashfs of=$cc/bin/ramips/openwrt-ramips-mt7620-root.squashfs bs=128k conv=sync
35+1 records in
36+0 records out
4718592 bytes (4.7 MB) copied, 0.0153264 s, 308 MB/s
cp $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a
$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/linux-3.18.29/scripts/dtc/dtc -O dtb -o $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/MT7620a.dtb ../dts/MT7620a.dts
#patch-dtb命令
$cc/staging_dir/host/bin/patch-dtb $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/MT7620a.dtb
#lzma生成vmlinux-mt7620a.bin.lzma
$cc/staging_dir/host/bin/lzma e $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a -lc1 -lp2 -pb2 $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a.bin.lzma
LZMA 4.65 : Igor Pavlov : Public domain : 2009-02-03
#mkimage根据vmlinux-mt7620a.bin.lzma生成vmlinux-mt7620a.uImage
mkimage -A mips -O linux -T kernel -C lzma -a 0x80000000 -e 0x80000000 -n "MIPS OpenWrt Linux-3.18.29" -d $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a.bin.lzma $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a.uImage
Image Name: MIPS OpenWrt Linux-3.18.29
Created: Tue May 10 20:43:41 2016
Image Type: MIPS Linux Kernel Image (lzma compressed)
Data Size: 1139383 Bytes = 1112.68 kB = 1.09 MB
Load Address: 80000000
Entry Point: 80000000
#组合vmlinux-mt7620a.uImage和root.squashfs生成最终固件openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin
cat $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/vmlinux-mt7620a.uImage $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.squashfs > $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin
#padjffs2命令处理固件
$cc/staging_dir/host/bin/padjffs2 $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin 4 8 16 64 128 256
padding image to 00596000
padding image to 00598000
padding image to 005a0000
padding image to 005c0000
if [ `stat -c%s "$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin"` -gt 8060928 ]; then echo "Warning: $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin is too big" >&2; else cp -fpR $cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin $cc/bin/ramips/openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin; fi
#dd处理root.jffs2-64k生成最终的文件系统
dd if=$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-64k of=$cc/bin/ramips/openwrt-ramips-mt7620-root.jffs2-64k bs=128k conv=sync
54+1 records in
55+0 records out
7208960 bytes (7.2 MB) copied, 0.00730228 s, 987 MB/s
#dd处理root.jffs2-128k，生成最终的文件系统
dd if=$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.jffs2-128k of=$cc/bin/ramips/openwrt-ramips-mt7620-root.jffs2-128k bs=128k conv=sync
54+1 records in
55+0 records out
7208960 bytes (7.2 MB) copied, 0.00964141 s, 748 MB/s
#dd处理root.ext4，生成最终的文件系统
dd if=$cc/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620/root.ext4 of=$cc/bin/ramips/openwrt-ramips-mt7620-root.ext4 bs=128k conv=sync
384+0 records in
384+0 records out
50331648 bytes (50 MB) copied, 0.171708 s, 293 MB/s
( cd $cc/bin/ramips ; find -maxdepth 1 -type f \! -name 'md5sums' -printf "%P\n" | sort | xargs md5sum --binary > md5sums )
( cd $cc/bin/ramips ; find -maxdepth 1 -type f \! -name 'md5sums' -printf "%P\n" | sort | xargs openssl dgst -sha256 > sha256sums )
make[5]: Leaving directory `$cc/target/linux/ramips/image'
make[4]: Leaving directory `$cc/target/linux/ramips'
make[3]: Leaving directory `$cc/target/linux'
make[2]: Leaving directory `$cc'
export MAKEFLAGS= ;make -w -r package/index
make[2]: Entering directory `$cc'
Generating package index...
Generating index for package ./IPKG_BUILD.20733/pkg_file.ipk
Generating index for package ./base-files_157.2-unknown_ramips_24kec.ipk
Generating index for package ./busybox_1.23.2-1_ramips_24kec.ipk
从Makefile剖析生成firmware
firmware由kernel和rootfs两个部分组成，要对两个部分先分别处理，然后再合并成一个.bin文件。先看一下这个流程。
“target/linux/ramips/image/Makefile” 文件中的最后一句：(eval
(call BuildImage))，将BuildImage展开在这里。BuildImage定义在 include/image.mk 文件中，其中定义了数个目标的规则。
define BuildImage
compile: compile-targets FORCE
**$(call Build/Compile)**
install: compile install-targets FORCE ...
$(call Image/BuildKernel) ## 处理vmlinux ...
$(call Image/mkfs/squashfs) ## 生成squashfs，并与vmlinux合并成一个.bin文件 ...
endef
处理vmlinux: Image/BuildKernel
target/linux/ramips/image/Makefile:
define Image/BuildKernel
cp $(KDIR)/vmlinux.elf $(BIN_DIR)/$(VMLINUX).elf
cp $(KDIR)/vmlinux $(BIN_DIR)/$(VMLINUX).bin
$(call CompressLzma,$(KDIR)/vmlinux,$(KDIR)/vmlinux.bin.lzma)
$(call MkImage,lzma,$(KDIR)/vmlinux.bin.lzma,$(KDIR)/uImage.lzma)
cp $(KDIR)/uImage.lzma $(BIN_DIR)/$(UIMAGE).bin
ifneq ($(CONFIG_TARGET_ROOTFS_INITRAMFS),)
cp $(KDIR)/vmlinux-initramfs.elf $(BIN_DIR)/$(VMLINUX)-initramfs.elf
cp $(KDIR)/vmlinux-initramfs $(BIN_DIR)/$(VMLINUX)-initramfs.bin
$(call CompressLzma,$(KDIR)/vmlinux-initramfs,$(KDIR)/vmlinux-initramfs.bin.lzma)
$(call MkImage,lzma,$(KDIR)/vmlinux-initramfs.bin.lzma,$(KDIR)/uImage-initramfs.lzma)
cp $(KDIR)/uImage-initramfs.lzma $(BIN_DIR)/$(UIMAGE)-initramfs.bin
endif
$(call Image/Build/Initramfs) endef
lzma压缩内核
build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620a/ 目录中:
lzma e vmlinux -lc1 -lp2 -pb2 vmlinux.bin.lzma
MkImage
build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620a/ 目录中：
mkimage -A mips -O linux -T kernel -C lzma -a 0x80000000 -e 0x80000000 -n "MIPS OpenWrt Linux-3.14.18" -d vmlinux.bin.lzma uImage.lzma
copy
VMLINUX:=$(IMG_PREFIX)-vmlinux --> openwrt-ramips-mt7620a-vmlinux
UIMAGE:=$(IMG_PREFIX)-uImage --> openwrt-ramips-mt7620a-uImage
cp $(KDIR)/uImage.lzma $(BIN_DIR)/$(UIMAGE).bin
把uImage.lzma复制到bin/ramips/目录下：
cp $(KDIR)/uImage.lzma bin/ramips/openwrt-ramips-mt7620a-uImage
制作squashfs，生成.bin: $(call Image/mkfs/squashfs)
define Image/mkfs/squashfs
@mkdir -p $(TARGET_DIR)/overlay
$(STAGING_DIR_HOST)/bin/mksquashfs4 $(TARGET_DIR) $(KDIR)/root.squashfs -nopad -noappend -root-owned -comp $(SQUASHFSCOMP) $(SQUASHFSOPT) -processors
$(if $(CONFIG_PKG_BUILD_JOBS),$(CONFIG_PKG_BUILD_JOBS),1)
$(call Image/Build,squashfs)
endif
mkdir -p $(TARGET_DIR)/overlay
mkdir -p build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips/overlay
mkdir -p $(TARGET_DIR)/overlay
mkdir -p build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/root-ramips/overlay
mksquashfs4
$(STAGING_DIR_HOST)/bin/mksquashfs4 $(TARGET_DIR) $(KDIR)/root.squashfs -nopad -noappend -root-owned -comp $(SQUASHFSCOMP) $(SQUASHFSOPT) -processors
$(if $(CONFIG_PKG_BUILD_JOBS),$(CONFIG_PKG_BUILD_JOBS),1)
制作squashfs文件系统，生成root.squashfs:
mksquashfs4 root-ramips root.squashfs -nopad -noappend -root-owned -comp gzip -b 256k -p '/dev d 755 0 0' -p '/dev/console c 600 0 0 5 1' -processors 1
$(call Image/Build,squashfs)
$(call Image/Build,squashfs)
在 target/linux/ramips/image/Makefile 中：
define Image/Build $(call Image/Build/$(1))
dd if=$(KDIR)/root.$(1) of=$(BIN_DIR)/$(IMG_PREFIX)-root.$(1) bs=128k conv=sync $(call Image/Build/Profile/$(PROFILE),$(1))
endef
dd if=(KDIR)/root.squashfsof=(BIN_DIR)/$(IMG_PREFIX)-root.squashfs bs=128k conv=sync
dd if=build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620a/root.squashfs of=bin/ramips/openwrt-ramips-mt7620-root.squashfs bs=128k conv=sync
(callImage/Build/Profile/(PROFILE),squashfs)
dd if=(KDIR)/root.squashfsof=(BIN_DIR)/$(IMG_PREFIX)-root.squashfs bs=128k conv=sync
dd if=build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7620a/root.squashfs of=bin/ramips/openwrt-ramips-mt7620-root.squashfs bs=128k conv=sync
(callImage/Build/Profile/(PROFILE),squashfs)
target/linux/ramips/mt7620a/profiles/00-default.mk, 中调用 Profile 函数：(eval
(call Profile,Default))
include/target.mk 中定义了 Profile 函数， 其中令 PROFILE=Default
define Image/Build/Profile/Default
$(call Image/Build/Profile/MT7620a,$(1)) ... endef
规则依赖序列如下
$(call Image/Build/Profile/$(PROFILE),squashfs)
--> $(call BuildFirmware/Default8M/squashfs,squashfs,mt7620a,MT7620a)
--> $(call BuildFirmware/OF,squashfs,mt7620a,MT7620a,8060928)
--> $(call MkImageLzmaDtb,mt7620a,MT7620a)
--> $(call PatchKernelLzmaDtb,mt7620a,MT7620a)
--> $(call MkImage,lzma,$(KDIR)/vmlinux-mt7620a.bin.lzma,$(KDIR)/vmlinux-mt7620a.uImage)
--> $(call MkImageSysupgrade/squashfs,squashfs,mt7620a,8060928)
其中的主要步骤：
- 复制： cp (KDIR)/vmlinux(KDIR)/vmlinux-mt7620a
- 生成dtb文件： (LINUXDIR)/scripts/dtc/dtc?Odtb?o(KDIR)/MT7620a.dtb ../dts/MT7620a.dts
- 将内核与dtb文件合并：(STAGINGDIRHOST)/bin/patch?dtb(KDIR)/vmlinux-mt7620a $(KDIR)/MT7620a.dtb
- 使用lzma压缩：(callCompressLzma,(KDIR)/vmlinux-mt7620a,$(KDIR)/vmlinux-mt7620a.bin.lzma
- 将lzma压缩后的文件经过mkimage工具处理，即在头部添加uboot可识别的信息。
接下来就是合并生成firmware固件了：
MkImageSysupgrade/squashfs, squashfs, mt7620a,8060928
cat vmlinux-mt7620a.uImage root.squashfs > openwrt-ramips-mt7620-mt7620a-squashfs-sysupgrade.bin
–> 制作squashfs bin文档, 并确认它的大小 < 8060928 才是有效的，否则报错。
总结： 整个流程下来，其实最烦索的还是对内核生成文件vmlinux的操作，经过了objcopy, patch-dtb, lzma, mkimage 等过程生成一个uImage，再与mksquashfs工具制作的文件系统rootfs.squashfs合并。
转：http://www.openwrtdl.com/wordpress/openwrt%E7%94%9F%E6%88%90%E5%9B%BA%E4%BB%B6firmware%E6%B5%81%E7%A8%8B
