[coreboot-gerrit] Patch set updated for coreboot: fa05648 arm: Prevent compilation of old, experimental SMP support

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9222

-gerrit

commit fa0564886926c367123d15927c3d1e1d6ecb2400
Author: Julius Werner <jwerner at chromium.org>
Date:   Tue Sep 23 20:53:20 2014 -0700

    arm: Prevent compilation of old, experimental SMP support
    
    The ARM SMP feature was added a long time ago and has never really been
    used by anyone since. We are still always compiling cpu_info() even
    though we don't use it, and it makes some dangerous assumptions about
    stack alignment that are not guaranteed anywhere.
    
    I'm planning to change the way the stack boundaries are defined. Rather
    than trying to work that into this unsafe, unused and hard to test
    feature, I think we should just seal it off with police tape and make
    sure that if anyone ever tries to use it again (which currently seems
    unlikely), they get forced to do their due diligence on making sure it
    works as intended.
    
    BUG=None
    TEST=Compiled Veyron_Pinky.
    
    Change-Id: Id25545cab88f29200c7672ef02c7804f0ac26399
    Signed-off-by: Stefan Reinauer <reinauer at chromium.org>
    Original-Commit-Id: 5b517fc46b030a6e50ef2f5e4d4a449b98ce16c6
    Original-Change-Id: I8a60bd30e8b27a22bb3da68ca84daea99424dee9
    Original-Signed-off-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/219680
    Original-Reviewed-by: Aaron Durbin <adurbin at chromium.org>
    Original-Reviewed-by: David Hendricks <dhendrix at chromium.org>
---
 src/arch/arm/Makefile.inc | 2 +-
 src/arch/arm/cpu.c        | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/arch/arm/Makefile.inc b/src/arch/arm/Makefile.inc
index 25f764c..e739d0b 100644
--- a/src/arch/arm/Makefile.inc
+++ b/src/arch/arm/Makefile.inc
@@ -117,7 +117,7 @@ ifeq ($(CONFIG_ARCH_RAMSTAGE_ARM),y)
 
 ramstage-y += stages.c
 ramstage-y += div0.c
-ramstage-y += cpu.c
+ramstage-$(CONFIG_COOP_MULTITASKING) += cpu.c
 ramstage-y += eabi_compat.c
 ramstage-y += boot.c
 ramstage-y += tables.c
diff --git a/src/arch/arm/cpu.c b/src/arch/arm/cpu.c
index f90c759..e02fed3 100644
--- a/src/arch/arm/cpu.c
+++ b/src/arch/arm/cpu.c
@@ -34,6 +34,11 @@
  */
 struct cpu_info *cpu_info(void)
 {
+#error "This is BROKEN! ARM stacks are currently not guaranteed to be " \
+       "STACK_SIZE-aligned in any way. If you ever plan to revive this " \
+       "feature, make sure you add the proper assertions " \
+       "(and maybe consider revising the whole thing to work closer to what " \
+       "arm64 is doing now)."
 	uintptr_t addr = ALIGN((uintptr_t)__builtin_frame_address(0),
 		CONFIG_STACK_SIZE);
 	addr -= sizeof(struct cpu_info);