Peter Tyser <pty...@xes-inc.com> wrote on 23/09/2009 14:17:51:
>
> On Wed, 2009-09-23 at 13:51 +0200, Joakim Tjernlund wrote:
> > NULL is an absolute value and should not be relocated.
> > After this correction code like:
> > void weak_fun(void) __attribute__((weak));
> > printf("weak_fun:%p\n", weak_fun);
> > will still print null after relocation.
> >
> > Signed-off-by: Joakim Tjernlund <joakim.tjernl...@transmode.se>
> > ---
> >
> > I have only tested this on 83xx and on a somewhat older u-boot.
> > The change is exactly the same on all PowerPC platforms though.
>
> Hi Jocke,
> I made the same changes recently, but ran into an "issue" that prevented
> me from sending the change upstream. Some boards/arches have the bss at
> address 0 and later relocate it, unlike every other NULL pointer. If
> you don't fix up the bss address, the board will not function. If you
> run readelf on an 83xx u-boot image vs a 85xx u-boot image it should be
> more clear what's going on. I was doing my testing on the XPedite5370
> fwiw.
Ouch, the horror continues :(
>
> In any case, the change as is would break some other arches. Seems like
> the proper workaround would be to "fix" the 85xx (and other arches) link
> script to locate the bss similar to the 83xx boards.
Yes, something should be done. Does it work for you with a "fixed" linker
script?
>
> It might be nice to consolidate all the ppc relocate code into 1
> function while we were at it.
Played around a little and this is what I got sofar, possibly
WS damged and fixups untested:
>From 5099be8f64a72080e89c325943b771932389c665 Mon Sep 17 00:00:00 2001
From: Joakim Tjernlund <joakim.tjernl...@transmode.se>
Date: Tue, 22 Sep 2009 23:24:46 +0200
Subject: [PATCH] relocation: Use C-functions to do relocate the GOT & fixups.
---
cpu/mpc83xx/start.S | 29 ++++++++---------------------
lib_ppc/board.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 21 deletions(-)
diff --git a/cpu/mpc83xx/start.S b/cpu/mpc83xx/start.S
index 26e3106..868b070 100644
--- a/cpu/mpc83xx/start.S
+++ b/cpu/mpc83xx/start.S
@@ -950,35 +950,22 @@ in_ram:
* Adjust got2 pointers, no need to check for 0, this code
* already puts a few entries in the table.
*/
- li r0,__got2_entr...@sectoff@l
la r3,GOT(_GOT2_TABLE_)
- lwz r11,GOT(_GOT2_TABLE_)
- mtctr r0
- sub r11,r3,r11
- addi r3,r3,-4
-1: lwzu r0,4(r3)
- add r0,r0,r11
- stw r0,0(r3)
- bdnz 1b
+ li r4,__got2_entr...@sectoff@l
+ lwz r5,GOT(_GOT2_TABLE_)
+ sub r5,r3,r5
+ mr r30,r5
+ bl __eabi_convert
#ifndef CONFIG_NAND_SPL
/*
* Now adjust the fixups and the pointers to the fixups
* in case we need to move ourselves again.
*/
-2: li r0,__fixup_entr...@sectoff@l
lwz r3,GOT(_FIXUP_TABLE_)
- cmpwi r0,0
- mtctr r0
- addi r3,r3,-4
- beq 4f
-3: lwzu r4,4(r3)
- lwzux r0,r4,r11
- add r0,r0,r11
- stw r10,0(r3)
- stw r0,0(r4)
- bdnz 3b
-4:
+ li r4,__fixup_entr...@sectoff@l
+ mr r5,r30
+ bl __eabi_uconvert
#endif
clear_bss:
diff --git a/lib_ppc/board.c b/lib_ppc/board.c
index 9e944fa..0afc7c3 100644
--- a/lib_ppc/board.c
+++ b/lib_ppc/board.c
@@ -148,6 +148,37 @@ static ulong mem_malloc_brk = 0;
************************************************************************
*/
+/* Relocate the .got2 pointers. */
+void __eabi_convert(unsigned long *low, unsigned long len,
+ unsigned long addend)
+{
+ unsigned long val;
+
+ for(--low; len; --len) {
+ val = *++low;
+ if (!val)
+ continue;
+ *low = val + addend;
+ }
+}
+/* Fixup any user initialized pointers (the compiler drops pointers to */
+/* each of the relocs that it does in the .fixup section). */
+void __eabi_uconvert(unsigned long *low, unsigned long len,
+ unsigned long addend)
+{
+ unsigned long val, *v2p, val2;
+
+ for(--low; len; --len) {
+ val = *++low;
+ val += addend;
+ *low = val;
+ v2p = (unsigned long *)val;
+ val2 = *v2p;
+ val2 += addend;
+ *v2p = val2;
+ }
+}
+
/*
* The Malloc area is immediately below the monitor copy in DRAM
*/
--
1.6.4.4
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