From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Date: Mon, 05 Oct 2009 13:37:36 -0500 Subject: [U-Boot] [PATCH v2] arm926ejs: 16-byte align stack to avoid LDRD/STRD problems In-Reply-To: <20091005165324.510fdadc@marrow.netinsight.se> References: <73173D32E9439E4ABB5151606C3E19E202EF7E99DC@SC-VEXCH1.marvell.com> <20091005152318.30bc6678@marrow.netinsight.se> <200910051635.05113.sr@denx.de> <20091005165324.510fdadc@marrow.netinsight.se> Message-ID: <4ACA3CF0.8040500@windriver.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Simon Kagstrom wrote: > U-boot for Marvell Kirkwood boards no longer work after the EABI changes > introduced in commit f772acf8a584067033eff1e231fcd1fb3a00d3d9. This > turns out to be caused by a stack alignment issue. The armv5te > instructions ldrd/strd instructions require 8-byte alignment to work > properly (otherwise undefined behavior), and start.S gave the stack a > 12-byte alignment. > > Tested on an OpenRD base board, where both printouts and ubifs stuff now > works. > > Signed-off-by: Simon Kagstrom Has this patch been tested on any other boards ? This patch looks ok, I am just concerned about regressions. Tom > --- > ChangeLog: > v2: Update after Andrews comments > * Mask away the low address bits to get 16-byte alignment > > cpu/arm926ejs/start.S | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/cpu/arm926ejs/start.S b/cpu/arm926ejs/start.S > index 8043322..cd3a6bd 100644 > --- a/cpu/arm926ejs/start.S > +++ b/cpu/arm926ejs/start.S > @@ -171,7 +171,10 @@ stack_setup: > #ifdef CONFIG_USE_IRQ > sub r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ) > #endif > - sub sp, r0, #12 /* leave 3 words for abort-stack */ > + sub r0, r0, #12 /* leave 3 words for abort-stack and */ > + mov r1, #7 /* 8-byte align stack for ldrd/strd */ > + and r1, r0 > + sub sp, r0, r1 > > clear_bss: > ldr r0, _bss_start /* find start of bss segment */