coreboot arm64: Add proper masks for setting SCTLR and SCR regs to 0 at init

Since RES1 and RES0 bits are marked as SBOP(Should-Be-One-or-Preserved) and
SBZP(Should-Be-Zero-or-Preserved) respectively, resetting the SCTLR and SCR
registers should be done with proper bitmask.

BUG=None
BRANCH=None
TEST=Compiles successfully and verified that the RES bits are preserved across
register writes.

Original-Change-Id: I5094ba7e51e8ea6f7d7612ba4d11b10dcbdb1607
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/207815
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
(cherry picked from commit dfb196b4063e4f94d1ba9d5e2d19bae624ed46b3)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I033a68b723fea83817aaa6402b86c78abd3e1da9
Reviewed-on: http://review.coreboot.org/8592
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@google.com>
Tested-by: build bot (Jenkins)
This commit is contained in:
Furquan Shaikh 2014-07-14 11:50:09 -07:00 committed by Marc Jones
parent f13c567c97
commit 9c8cfc5c25
1 changed files with 16 additions and 2 deletions

View File

@ -21,9 +21,17 @@
#include <arch/asm.h>
ENTRY(arm64_el3_startup)
mov x0, xzr
/* Set all bits in SCTLR_EL3 to 0 except RES1 and RES0 */
mrs x0, SCTLR_EL3
ldr x1, .SCTLR_MASK
and x0, x0, x1
msr SCTLR_EL3, x0
/* Set all bits in SCR_EL3 to 0 except RES1 and RES0 */
mrs x0, SCR_EL3
ldr x1, .SCR_MASK
and x0, x0, x1
msr SCR_EL3, x0
/* Have stack pointer use SP_EL0. */
msr SPSel, #0
isb
@ -38,6 +46,12 @@ ENTRY(arm64_el3_startup)
ldr x1, .entry
br x1
.align 4
.SCTLR_MASK:
.quad 0x0FFFFEFF0
.SCR_MASK:
.quad 0x0FFFFC070
.align 4
/*
* By default branch to main() and initialize the stack according