Can't get 7248 PreP boot disk working in 2.6

Can't get 7248 PreP boot disk working in 2.6

[linuxppcdev]

Running an IDE disk and booting off floppy (cheap dual boot, can use the
hard drive to boot AIX this way).

I've never had trouble making a boot disk for 2.4.x kernels. Using the
current bitkeeper 2.4 and 2.6 however, the 2.4 works fine and the 2.6
reads a few sectors and goes to the System Maint disk insert dialog.
Tried different floppies, etc.

To make these I do a make zImage then dd the resulting
zImage.prep to a floppy.

I know there is some odd kernel size limitation which is less than the
actual size of the floppy but that isn't the problem.

# ls -l  bk*/arch/ppc/boot/images/zImage.prep
-rwxr-xr-x    1 root     nogroup   1210629 Mar 16 11:11 bk24/arch/ppc/boot/images/zImage.prep
-rwxr-xr-x    1 root     nogroup   1028225 Mar 16 16:43 bk26/arch/ppc/boot/images/zImage.prep

The 2.4 image is actually larger than the 2.6 image (more stuff in modules
in the 2.6 compile).

# file bk*/arch/ppc/boot/images/zImage.prep
bk24/arch/ppc/boot/images/zImage.prep: x86 boot sector
bk26/arch/ppc/boot/images/zImage.prep: x86 boot sector

I have 2.6.4 running on some macs, even a 7200 so I'm curious if
anyone has clues about this problem?

Bob

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: Can't get 7248 PreP boot disk working in 2.6

[Paul Mackerras]

linuxppcdev@qbjnet.com writes:

> I've never had trouble making a boot disk for 2.4.x kernels. Using the
> current bitkeeper 2.4 and 2.6 however, the 2.4 works fine and the 2.6
> reads a few sectors and goes to the System Maint disk insert dialog.
> Tried different floppies, etc.

There is a bug in arch/ppc/boot/utils/mkprep.c in 2.6.  This patch
should fix it.  Tom, how about sending this to Linus and Andrew?

diff -urN linux-2.5/arch/ppc/boot/utils/mkprep.c linux-2.4/arch/ppc/boot/utils/mkprep.c
--- linux-2.5/arch/ppc/boot/utils/mkprep.c	2004-01-03 11:27:07.000000000 +1100
+++ linux-2.4/arch/ppc/boot/utils/mkprep.c	2003-12-31 09:32:23.000000000 +1100
@@ -219,6 +219,8 @@
   pe.number_of_sectors = cpu_to_le32(2*18*80-1);
 #endif /* __i386__ */

+  memcpy(&block[0x1BE],&pe,sizeof(pe));
+
   write( out, block, sizeof(block) );
   write( out, entry, sizeof(*entry) );
   write( out, length, sizeof(*length) );

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: Can't get 7248 PreP boot disk working in 2.6

[Tom Rini]

On Wed, Mar 17, 2004 at 10:13:29PM +1100, Paul Mackerras wrote:

> linuxppcdev@qbjnet.com writes:
>
> > I've never had trouble making a boot disk for 2.4.x kernels. Using the
> > current bitkeeper 2.4 and 2.6 however, the 2.4 works fine and the 2.6
> > reads a few sectors and goes to the System Maint disk insert dialog.
> > Tried different floppies, etc.
>
> There is a bug in arch/ppc/boot/utils/mkprep.c in 2.6.  This patch
> should fix it.  Tom, how about sending this to Linus and Andrew?
>
> diff -urN linux-2.5/arch/ppc/boot/utils/mkprep.c linux-2.4/arch/ppc/boot/utils/mkprep.c
> --- linux-2.5/arch/ppc/boot/utils/mkprep.c	2004-01-03 11:27:07.000000000 +1100
> +++ linux-2.4/arch/ppc/boot/utils/mkprep.c	2003-12-31 09:32:23.000000000 +1100
> @@ -219,6 +219,8 @@
>    pe.number_of_sectors = cpu_to_le32(2*18*80-1);
>  #endif /* __i386__ */
>
> +  memcpy(&block[0x1BE],&pe,sizeof(pe));
> +
>    write( out, block, sizeof(block) );
>    write( out, entry, sizeof(*entry) );
>    write( out, length, sizeof(*length) );

Done.

--
Tom Rini
http://gate.crashing.org/~trini/

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/