On Thu, 8 Apr 2010 10:37:08 +0200
Joakim Tjernlund <joakim.tjernl...@transmode.se> wrote:
> Kim Phillips <kim.phill...@freescale.com> wrote on 2010-04-08 10:27:03:
> >
> > The documentation is confusing: the e300c2 has its FPU chopped off -
> > the FP registers are simply not there.
> >
> > this is a good catch by Jocke - it would be best if generic 83xx code
> > didn't depend on the ppcDW* accessors.
>
> That or one could impl. ppcDW* using normal load/store insns for 832x.
> Either way the ppcDW* should be inlined as the overhead for doing
> function calls isn't something you want when looking for speed.
another good point, but it seems they were added primarily for code
density benefits. I think we can do something like this in the
meantime:
>From 686d3bb7a732ec36beec169c4eaf4882382d3aa2 Mon Sep 17 00:00:00 2001
From: Kim Phillips <kim.phill...@freescale.com>
Date: Thu, 8 Apr 2010 18:22:13 -0500
Subject: [PATCH] mpc83xx: implement ppcDW{load,store} accessors for e300c2
e300c2 core based processors (MPC832x) don't have an FPU: provide
alternative, gpr based accessor functions for code compatibility.
Suggested-by: Joakim Tjernlund <joakim.tjernl...@transmode.se>
Signed-off-by: Kim Phillips <kim.phill...@freescale.com>
---
arch/ppc/cpu/mpc83xx/start.S | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/ppc/cpu/mpc83xx/start.S b/arch/ppc/cpu/mpc83xx/start.S
index 68bb620..6bfce57 100644
--- a/arch/ppc/cpu/mpc83xx/start.S
+++ b/arch/ppc/cpu/mpc83xx/start.S
@@ -139,14 +139,28 @@ get_pvr:
.globl ppcDWstore
ppcDWstore:
+#if !defined(CONFIG_MPC832x)
lfd 1, 0(r4)
stfd 1, 0(r3)
+#else
+ lwz r5, 0(r4)
+ stw r5, 0(r3)
+ lwz r5, 4(r4)
+ stw r5, 4(r3)
+#endif
blr
.globl ppcDWload
ppcDWload:
+#if !defined(CONFIG_MPC832x)
lfd 1, 0(r3)
stfd 1, 0(r4)
+#else
+ lwz r5, 0(r3)
+ stw r5, 0(r4)
+ lwz r5, 4(r3)
+ stw r5, 4(r4)
+#endif
blr
#ifndef CONFIG_DEFAULT_IMMR
--
1.7.0.5
but 83xx is still missing (at least) the post_word_{load,store} functions:
post/libpost.a(post.o): In function `post_bootmode_get':
/home/kim/git/u-boot/post/post.c:107: undefined reference to `post_word_load'
post/libpost.a(post.o): In function `post_bootmode_test_on':
/home/kim/git/u-boot/post/post.c:154: undefined reference to `post_word_load'
/home/kim/git/u-boot/post/post.c:160: undefined reference to `post_word_store'
post/libpost.a(post.o): In function `post_bootmode_test_off':
/home/kim/git/u-boot/post/post.c:165: undefined reference to `post_word_load'
/home/kim/git/u-boot/post/post.c:169: undefined reference to `post_word_store'
post/libpost.a(post.o): In function `post_bootmode_init':
/home/kim/git/u-boot/post/post.c:90: undefined reference to `post_word_load'
/home/kim/git/u-boot/post/post.c:99: undefined reference to `post_word_store'
Michael, can you resubmit something more comprehensive, something that
builds for 83xx with CONFIG_POST turned on?
Kim
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