Unpacking boot.img

Written a script to upack the files from the boot.img

 [stevep@localhost image]$  ,/rksp_unpack_boot.img.pl
unpacked
3339 blocks
edit files....

[stevep@localhost image]$ ls BOOT*
BOOT-20120112_1630/

[stevep@localhost image]$ ll BOOT-20120112_1630/
total 1600
drwxrwx--x 2 stevep stevep    4096 Jan 12 16:30 data/
-rw-r--r-- 1 stevep stevep     278 Jan 12 16:30 default.prop
drwxr-xr-x 2 stevep stevep    4096 Jan 12 16:30 dev/
-rwxr-x--- 1 stevep stevep   94200 Jan 12 16:30 init*
-rwxr-x--- 1 stevep stevep      45 Jan 12 16:30 init_battery.sh*
-rwxr-x--- 1 stevep stevep    1677 Jan 12 16:30 init.goldfish.rc*
-rwxr-xr-x 1 stevep stevep 1360652 Jan 12 16:30 initlogo.rle*
-rwxr-x--- 1 stevep stevep   15255 Jan 12 16:30 init.rc*
-rwxr-x--- 1 stevep stevep    2710 Jan 12 16:30 init.rk29board.rc*
drwxr-xr-x 2 stevep stevep    4096 Jan 12 16:30 proc/
-rw-r--r-- 1 stevep stevep  113525 Jan 12 16:30 rk29xxnand_ko.ko
drwxr-x--- 2 stevep stevep    4096 Jan 12 16:30 sbin/
drwxr-xr-x 2 stevep stevep    4096 Jan 12 16:30 sys/
drwxr-xr-x 2 stevep stevep    4096 Jan 12 16:30 system/
-rw-r--r-- 1 stevep stevep       0 Jan 12 16:30 ueventd.goldfish.rc
-rw-r--r-- 1 stevep stevep    3764 Jan 12 16:30 ueventd.rc
-rw-r--r-- 1 stevep stevep    1002 Jan 12 16:30 ueventd.rk29board.rc

Here's thescript:

rksp_unpack_boot.img.pl

==================

#!/usr/bin/perl

#    $ ./rksp_unpack_boot.img.pl

$imgfn = "boot.img";

$BOOTDIR = "BOOT-".`date +%Y%m%d_%H%M`;
chomp $BOOTDIR;
system "mkdir -p $BOOTDIR";

system "rkunpack $imgfn";
system "mv ".$imgfn."-raw $BOOTDIR/".$imgfn."-cpio.gz";
system "gzip -d $BOOTDIR/".$imgfn."-cpio.gz";
system "(cd $BOOTDIR/; cpio -i < ".$imgfn."-cpio)";
system "rm $BOOTDIR/".$imgfn."-cpio";
print "edit files....\n";

admin said

Thanks a lot ttz642t.

 

I have hosted some files here:

/assets/tools/Firmware/Rockchip_CPU_based/an10g2_dump.pl

/assets/tools/Firmware/Rockchip_CPU_based/rksp_unpack_boot.img.pl

and naobsd rkutils statically compiled on Linux: 

/assets/tools/Firmware/Rockchip_CPU_based/rkutils-bin.tgz

 

I'll complete/update as necessary.

I've moved over to the wiki, don't like forums, see:

• http://arctablet.com/wiki/index.php/Archos_Arnova_10_G2_Linux_Development

Anybody know how to add attachments to the wiki ?

finless said

Well it's a lot easier to unpack with this.... This is what I use

#strip the header. The count is set much larger than the file size as DD hits EOF anyway.

dd if=boot.img of=initrd.gz skip=8 bs=1 count=20000000

# unzip boot.img to a work folder. gzip disregards trailing garbage in the footer.

mkdir work;cd work;zcat ../initrd.gz|cpio -idm

 

Done

Bob,

Using the rkunpack tool does an integrity check on the image, ie it checkes the image size and crc.

admin said

ttz642t said

I've moved over to the wiki, don't like forums, see:

• http://arctablet.com/wiki/index.php/Archos_Arnova_10_G2_Linux_Development

Anybody know how to add attachments to the wiki ?

Thanks again ttz642t for your help documenting the Arnova G2 firmware manipulation tools.

The WIKI should accept uploads, but perl are currently refused for security. I'll have a look if this can be safely configured or if we should look for another way... 

I've finished phase 1 of the linux work, have sucessfully reflashed two different 10 G2 tablets with the v1.2 (finless) rom. No more Windowz 🙂

I've re-aranged the wiki pages a bit btw.

finless said

ttz642t, I was looking at your perl script:

 #!/usr/bin/perl
# $ rksp_pack_boot.img.pl 20120111_2229/

$BOOTDIR = $ARGV[0];
$BOOTIMGDIR = "BOOTIMG-".`date +%Y%m%d_%H%M`;
chomp $BOOTIMGDIR;
system "mkdir -p $BOOTIMGDIR";

print "Create $BOOTIMGDIR/boot.img from files ,,,\n";
system "find $BOOTDIR -exec touch -d '1970-01-01 01:00' {} \\;";
system "(cd $BOOTDIR; find .  ! -name '.' -print | /bin/cpio -oa --format=newc > ../$BOOTIMGDIR/boot.img-cpio)";
system "gzip $BOOTIMGDIR/boot.img-cpio";
system "rkcrc -k $BOOTIMGDIR/boot.img-cpio.gz $BOOTIMGDIR/boot.img";
system "rm $BOOTIMGDIR/boot.img-cpio.gz";

 

What I do not see (unless I am missing it) is any thing that replace the first 4 bytes of the gzip'ed and rxcrc'd new boot.img.  When gzip does it's thng the first four bytes of boot.img say PARM.  This needs to be changed to KRNL or the Arnova will not boot.  I have been editing the final boot.img with a hex editor to replace PARM with KRNL.  Did you possibly modify rkcrc to handle that and thats why I am not seeing it in this script?  Maybe thats the -k parameter you added to rkcrc?

 

Bob<!--
NewPP limit report
Preprocessor node count: 19/1000000
Post-expand include size: 0/2097152 bytes
Template argument size: 0/2097152 bytes
Expensive parser function count: 0/100
-->

Corrext, rkcrc calculates the lengeth of the text block and prefixes it and appends the crc and finally prefixes wither PARM or KRNL depending on switch -p or -k.