Re: [jornada] GPE 0.7.2 for jornada 720

On Wed, Feb 11, 2004 at 01:23:06PM +0100, Jacek Lipkowski wrote:
 
> Also as some of you may remember, there was a problem running newer
> familiar binaries that had elf entry points set to a low address. I think
> G Almasi solved this problem in his 820 patches - this was probably caused
> by the PID register being set incorrectly - this may be useful for the
> people trying to run newer handhelds.org distributions, when booting via
> hpcboot.

Indeed. I've been trying to wrap my brane around why init hung during
boot for the last week or so. Traced it to execve() and into the
load_elf_binary() in linux/fs/binfmt_elf.c. The hang took place when
padzero() was called. Zeroing out the PID register fixed the problem; if
init hangs on your jornada 720, apply this patch:

--- arch/arm/mach-sa1100/jornada720.c-orig 2004-02-12 21:15:50.000000000 -0500
+++ arch/arm/mach-sa1100/jornada720.c 2004-02-12 21:17:35.000000000 -0500
@@ -242,6 +242,10 @@
 {
         int ret;
          
+ /* we need to fix the PID register, which was left on by WinCE */
+ /* Copied from j820 patch */
+ asm volatile ("mov r0, #0; mcr p15, 0, r0, c13, c0,0;");
+
        GPDR |= GPIO_GPIO20;
        TUCR = JORTUCR_VAL; /* set the oscillator out to the SA-1101 */

...to linux/arch/arm/mach-sa1100/jornada720.c. I haven't tested this on
a j720 with a flashboard since I don't (yet!) have one. If this patch
doesn't break flashboard-equipped j720s, can we get it added to the
tree? (this patch is against 2.4.17, but since it's essentially a
one-liner, I wouldn't think it would cause any issues in the 2.4 tree,
and may well work fine on the 2.6 tree. YMMV. =)

--noah

-- 
"Neil! Your bed's on fire!"