From 6149776e7312b6c2417aa8c3621f864b36cea7cd Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Wed, 19 Jun 2013 20:48:06 -0700 Subject: [PATCH] libpayload: ARM: Don't leave alignment checking on after the exception test Currently, the exception handling code on ARM in libpayload turns on alignment checks as an easy way to generate an exception for testing purposes. It was leaving it on which disabled unaligned accesses for other, unlreated code running later. This change adjusts the code so the original value of the alignment bit is restored after the test exception. Built and booted into depthcharge on pit with an unaligned accesses added after the call to exception_init in the depthcharge's main. Before this change, the access caused an exception. After this change, the access completed successfully. Change-Id: If92cab3cc8eabca7c5b0560ce88a8796a27fe3b2 Signed-off-by: Gabe Black Reviewed-on: https://gerrit.chromium.org/gerrit/59372 Reviewed-by: Stefan Reinauer Commit-Queue: Gabe Black Tested-by: Gabe Black Reviewed-on: http://review.coreboot.org/4255 Reviewed-by: Ronald G. Minnich Tested-by: build bot (Jenkins) --- payloads/libpayload/arch/armv7/exception.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/payloads/libpayload/arch/armv7/exception.c b/payloads/libpayload/arch/armv7/exception.c index 5e4e23d6a6..9efc312833 100644 --- a/payloads/libpayload/arch/armv7/exception.c +++ b/payloads/libpayload/arch/armv7/exception.c @@ -143,9 +143,8 @@ void exception_init(void) sctlr &= ~sctlr_te; /* Set V=0 in SCTLR so VBAR points to the exception vector table. */ sctlr &= ~sctlr_v; - /* Enforce alignment. */ - sctlr |= sctlr_a; - set_sctlr(sctlr); + /* Enforce alignment temporarily. */ + set_sctlr(sctlr | sctlr_a); extern uint32_t exception_table[]; set_vbar((uintptr_t)exception_table); @@ -153,4 +152,7 @@ void exception_init(void) test_abort = 1; exception_test(); test_abort = 0; + + /* Restore alignment settings. */ + set_sctlr(sctlr); }