[Patch] [arm] support older plebs

[Patch] [arm] support older plebs

[Geoffrey Lee]

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Hi all,


This patch has been in my patch directory for a while.

The PLEB is a SA-1100-based ARM computer developed at CSE at the
University of New South Wales.  I have discovered some of the earlier
models would not set register 1 properly, which was required for Linux
to boot.  This was inside their (very old) kernel tree but which they 
never submitted for inclusion (?)  It is a Photon1 with catapult
bootloader combination.


	- G.
	
-- 
char p[] = "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
  "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
  "\x80\xe8\xdc\xff\xff\xff/bin/sh";



[-- Attachment #2: arm-pleb.patch --]
[-- Type: text/plain, Size: 538 bytes --]

diff -urNp -X exclude linux-2.4.19-pleb.orig/arch/arm/kernel/head-armv.S linux-2.4.19-pleb/arch/arm/kernel/head-armv.S
--- linux-2.4.19-pleb.orig/arch/arm/kernel/head-armv.S	2002-10-29 18:57:10.000000000 +0800
+++ linux-2.4.19-pleb/arch/arm/kernel/head-armv.S	2002-10-29 19:18:42.000000000 +0800
@@ -130,6 +130,9 @@ __entry:
  */
 		mov	r1, #MACH_TYPE_L7200
 #endif
+#if defined(CONFIG_SA1100_PLEB)
+		mov	r1, #MACH_TYPE_PLEB
+#endif
 
 		mov	r0, #F_BIT | I_BIT | MODE_SVC	@ make sure svc mode
 		msr	cpsr_c, r0			@ and all irqs disabled

Re: [Patch] [arm] support older plebs

[Russell King]

On Wed, Mar 26, 2003 at 12:13:58AM +0800, Geoffrey Lee wrote:
> The PLEB is a SA-1100-based ARM computer developed at CSE at the
> University of New South Wales.  I have discovered some of the earlier
> models would not set register 1 properly, which was required for Linux
> to boot.  This was inside their (very old) kernel tree but which they 
> never submitted for inclusion (?)  It is a Photon1 with catapult
> bootloader combination.

I've been killing these - people should really be passing the right
value of r1 to the kernel.  Think what happens when 200 different
machine types add these 3 lines.

A saner solution would be to define this appropriately if we're only
being built for one platform.

BTW, please send ARM stuff to the linux-arm-kernel list.  See
http://lists.arm.linux.org.uk/mailman/listinfo/

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: [Patch] [arm] support older plebs

[Geoffrey Lee]

[cc-ing to linux-arm-kernel ]

On Tue, Mar 25, 2003 at 04:38:43PM +0000, Russell King wrote:
> On Wed, Mar 26, 2003 at 12:13:58AM +0800, Geoffrey Lee wrote:
> > The PLEB is a SA-1100-based ARM computer developed at CSE at the
> > University of New South Wales.  I have discovered some of the earlier
> > models would not set register 1 properly, which was required for Linux
> > to boot.  This was inside their (very old) kernel tree but which they 
> > never submitted for inclusion (?)  It is a Photon1 with catapult
> > bootloader combination.
> 
> I've been killing these - people should really be passing the right
> value of r1 to the kernel.  Think what happens when 200 different
> machine types add these 3 lines.
> 

I totally agree that it is wrong not to set r1.


Thank goodness that in 2.4.x not many arm boards need this hack :)

Anyway, inside the (very old) pleb kernel tree, it was marked as a "hack".  

> A saner solution would be to define this appropriately if we're only
> being built for one platform.
> 

Yes.  That sounds good.


	-- G.
-- 
char p[] = "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"
  "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"
  "\x80\xe8\xdc\xff\xff\xff/bin/sh";