brun_mtd

steven james pyro at linuxlabs.com
Wed May 21 09:32:01 CEST 2003


Greetings,

The DoC has hardware support for a 512B boot plock. On powerup, it loads
the first block into a block that 'just happens' to map the end of the
block at 0xf000:0xfff0. If the first block has an ECC error, the second
block is copied instead (so two copies of docipl).

IIRC, the seek=128 is used so that two copies of LinuxBIOS can be stored,
one as a fallback image though full support for that never got implemented
in the older boards.

G'day,
sjames



On Wed, 21 May 2003, Xavier Pegenaute wrote:

> Hello,
> 
> In the script of src/util/mtd/burn_mtd there are these lines ..
> 
> - dd conv=notrunc conv=sync bs=65536 if=${linux} of=vmlinux.bin.gz.block
> With this we if exist we don't trunc and fix the size of 
> vmlinux.bin.gz.block, if it's more smaller than 65536 we put 0 until 
> this size.
> 
> - dd conv=notrunc conv=sync bs=63k if=${linuxbios} of=linuxbios.block
> The same but with 63k.
> 
> - dd conv=notrunc if=docipl of=/dev/mtd0
> We write without trunc /dev/mtd0 with the source of docipl.
> 
> - dd conv=notrunc if=docipl of=/dev/mtd0 seek=1
> The same but this time we skip 1 block of "bs" (i supose that we can 
> remind the value of bs in the last line, then sizeof(docipl) ).
> 
> - dd conv=notrunc if=linuxbios.block of=/dev/mtd0 seek=2
> Without trunc we write linuxbios.block to mtd, skipping 2 times the last 
> size (sizeof(docipl) ).
> 
> - dd conv=notrunc if=vmlinux.bin.gz.block of=/dev/mtd0 seek=128
> Now without trunc write vmlinux skipping 128 times the size of 
> linuxbios.block.
> 
> 
> My questions, are:
> 
> Why we write two times docipl ?
> And why we skip 128 times the size of linuxbios.block ? (i supose that 
> i'm wrong, any one can help me with these)
> 
> 
> Thanks a lot for your patience.
> Xavi.
> 
> _______________________________________________
> Linuxbios mailing list
> Linuxbios at clustermatic.org
> http://www.clustermatic.org/mailman/listinfo/linuxbios
> 

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