Issue in uncompressing zImage

Issue in uncompressing zImage

[KARTHIK SEKURU]

Hi,
I'm doing kernel porting to arm926 based FPGA board,very minimal setup
(uart + timer only)
I'm getting kernel panic after cramfs root file system is mounted,I am
expecting to enter login prompt after root file system is mounted.

Below are the details

#define PLAT_PHYS_OFFSET       0x80000000 (with 128 MB SDRAM)
#define CONFIG_PAGE_OFFSET  0xc0000000


Physical memory : 128MB (0x80000000 to 88000000)

ZRELADDR = 0x80008000
PARAMS_PHYS = 0x80000100
INITRD_PHYS = 0x80800000

Kernel cmd line : mem=32M console=ttySAC0,115200 root=/dev/ram0
rootfstype=cramfs init=/linuxrc initrd=0x80800000,8M user_debug=31





I am not using u-boot and doing all the required initializations through
trace32 cmm script.





After compiling the kernel, when I load vmlinux(through trace32) at
0x80008000, the kernel runs upto mounting the filesystem(though there is
some issue in mounting the filesystem).



But when I load zImage at the same address i.e 0x80008000, I am getting



*Uncompressing Linux...*

* *

*uncompression error*

* *

* -- System halted*



in the console.



I made sure that I am enabling the config options CONFIG_XZ_DEC (xz
decompression support) through menuconfig.

I suspected on the cramfs memory location and then tried loading only
zImage at 0x80008000.,even after this the result is same.



Please let me know where could be the issue.
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Issue in uncompressing zImage

[wintermute]

On Thu, Apr 12, 2012 at 03:37:37PM +0530, KARTHIK SEKURU wrote:
> But when I load zImage at the same address i.e 0x80008000, I am getting
> *Uncompressing Linux...*
> *uncompression error*
> * -- System halted*
> I made sure that I am enabling the config options CONFIG_XZ_DEC (xz
> decompression support) through menuconfig.
> 
> I suspected on the cramfs memory location and then tried loading only
> zImage at 0x80008000.,even after this the result is same.
> Please let me know where could be the issue.

I think that the kernel is uncompressing itself at an address too near
to the image address, thus overwriting the compressed image.
Anyways you can see that the error you encounter is caused by this
routine:
http://lxr.linux.no/#linux+v3.3.1/lib/decompress_inflate.c#L159

Hope it helps

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