kernel panic if ramdisk image is in parallel dataflash

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Alex_Sv
Posts: 9
Joined: Thu Jun 30, 2005 10:41 am

kernel panic if ramdisk image is in parallel dataflash

Thu Jul 14, 2005 4:56 pm

I'm trying to start Linux from parrallel flash.
imls command gives:
Image at 10020000
ARM Linux kernel Image (gzip compr)
Data size 503151
Load Addr 20008000
Entry Point 20008000
...
Image at 100D0000
ARM Linux RAMDisk Image(gzip compressed)
Data size 1194754
Load addr 20a00000
entry point 20a00000
...
I'm trying bootm 10020000 100D0000 - kernel starts, but can't find ramdisk - kernel panic.
If i'm trying tftp unzipped ramdisk first at location 0x20a00000, then bootm 10020000 - allOK.
my runtime environment :
bootargs root=/dev/ram rw initrd=0x20a00000,0x500000 ramdisk_size=5000 console... mem=16M (I use my own board with 16m SDRAM and AT49DB322A flash)
What am i doing wrong? Maybe u-boot can't unzip ramdisk image from flash?
conger
Posts: 28
Joined: Tue Jul 20, 2004 3:05 am

Fri Jul 15, 2005 6:43 am

see if your ramdisk is also a (I think) zImage? I might be mis-remembering what the image is called. There is a mkimage tool that comes with U-boot that you will need to use on the gzipped ramdisk if you specify the ramdisk address in the bootm command.

If you do not want to bother with making the ramdisk an image (I do not for my board), you can just run the bootm command with only the kernel image address as you mentioned. I believe it will still work even if the ramdisk is gzipped, as you said you tried tftp-ing an unzipped ramdisk but did not say if you had tried a zipped one too. It should detect it, I guess :roll: . For myself, I do just that, only specify the kernel image address, and have the gzipped ramdisk already in RAM. The kernel detects a gzipped ramdisk, then automatically unzips and mounts it. I didn't have to do anything special for it to do that, is why I say above 'I guess' as far as it detecting it. Hope this helps :)

On second thought, check out the U-Boot documentation for more information on the mkimage tool. I know that one of the reasons you might want to make it an image is so it can be placed anywhere in memory and the bootm command will remove the image header and decompress it into the proper location for mounting for you. But you could also store the raw zipped disk in parallel Flash and copy it to RAM before running the boot command, I suppose. Its up to you. I guess the point I took a long time making is that specifying the ramdisk address in the bootm command means it is expecting to find a specially formatted ramdisk, so if not it won't detect it properly which is the source of the error you inquired about :)

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