brun_mtd

[Xavier Pegenaute]

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.

[steven james]

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
> [e-mail]
> http://www.clustermatic.org/mailman/listinfo/linuxbios

[Xavier Pegenaute]

steven james wrote:
> 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.

Ok, then if i want make a memory map of a eeprom, it will be like this:
0-511 (0x0 - 0x1FF) docipl 512 Bytes
512-1023 (0x200 - 0x3FF)  docipl (security copy) 512 Bytes
1024-65535 (0x400 - 0xFFFF)  linuxbios.block 64512 Bytes
65536-8323071 (0x10000 - 0x7EFFFF)  Free Space 8257536 Bytes = 128x64512
8323072-9109503  (0x7F0000 - 0x8AFFFF)  vmlinux.bin.gz.block 786432 Bytes

Then also if im'not wrong, when we make the reset EEPROM 0x0 - 0xFFFF is 
mapped to the top of memory addres space 0xFFFF0000 - 0xFFFFFFFF, and 
then the start point 0xFFFFFFF0 is visible in linuxbios.block.

If this is right, sorry but i didn't find the jump into the code of 
docipl, i suposed that the initial label is "sis630spd_start:" in 
ipl.S., any one know where is the jump ?

Regards.
Xavi.
> > 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)

[steven james]

Greetings,

At the end of ipl.S,

reset_vector:
    .byte 0xea
    .word 0x0000, DOC_WIN_SEG

is the jmp instruction hand assembled.

G'day,
sjames

On Wed, 21 May 2003, Xavier Pegenaute wrote:
> steven james wrote:
> > 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.
>
> Ok, then if i want make a memory map of a eeprom, it will be like this:
> 0-511 (0x0 - 0x1FF) docipl 512 Bytes
> 512-1023 (0x200 - 0x3FF)  docipl (security copy) 512 Bytes
> 1024-65535 (0x400 - 0xFFFF)  linuxbios.block 64512 Bytes
> 65536-8323071 (0x10000 - 0x7EFFFF)  Free Space 8257536 Bytes = 128x64512
> 8323072-9109503  (0x7F0000 - 0x8AFFFF)  vmlinux.bin.gz.block 786432 Bytes
>
> Then also if im'not wrong, when we make the reset EEPROM 0x0 - 0xFFFF is 
> mapped to the top of memory addres space 0xFFFF0000 - 0xFFFFFFFF, and 
> then the start point 0xFFFFFFF0 is visible in linuxbios.block.
>
> If this is right, sorry but i didn't find the jump into the code of 
> docipl, i suposed that the initial label is "sis630spd_start:" in 
> ipl.S., any one know where is the jump ?
>
> Regards.
> Xavi.
> > > 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)

[ollie lho]

On Wed, 2003-05-21 at 21:31, steven james wrote:
> 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).
>
> 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 ?

First of all, you are way wrong with what seek=# means. It skips # of
(output) blocks of the output device. It has nothing to do with
sizeof(some image). Please man dd for detail.

There are two copies for IPL one at offset 0 the other at offset 512B
(seek=1).
> > And why we skip 128 times the size of linuxbios.block ? (i supose that 
> > i'm wrong, any one can help me with these)

The size of linuxbios.block is 63kB plus the 2 copies of IPL == 64kB ==
128 blocks.

[Xavier Pegenaute]

ollie lho wrote:
> > > 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 ?
>
> First of all, you are way wrong with what seek=# means. It skips # of
> (output) blocks of the output device. It has nothing to do with
> sizeof(some image). Please man dd for detail.
>
> There are two copies for IPL one at offset 0 the other at offset 512B
> (seek=1).
>
> And why we skip 128 times the size of linuxbios.block ? (i supose that 
> i'm wrong, any one can help me with these)
>
> The size of linuxbios.block is 63kB plus the 2 copies of IPL == 64kB ==
> 128 blocks.

Ok, then the default block size (bs) for input and output is 512 Bytes, 
thank you.

Then finally the map of eeprom is this:

0-511 (0x0 - 0x1FF) docipl 512 Bytes
512-1023 (0x200 - 0x3FF)  docipl (security copy) 512 Bytes
1024-65535 (0x400 - 0xFFFF)  linuxbios.block 64512 Bytes
65536-851967 (0x10000 - 0xCFFFF)  vmlinux.bin.gz.block 786432 Bytes

Thanks a lot.
Xavi.