[coreboot-gerrit] Patch set updated for coreboot: 35e4e7b armv7: preserve bootblock invocation parameter

[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/9842

-gerrit

commit 35e4e7b749204f1bdb9678c60ace04336efc6593
Author: Vadim Bendebury <vbendeb at chromium.org>
Date:   Mon Mar 2 11:33:13 2015 -0800

    armv7: preserve bootblock invocation parameter
    
    Some platforms may pass as a parameter the maskrom or vendor startup
    code information when calling the bootblock.
    
    Make sure the bootblock startup code saves this parameter for use by
    coreboot. As we don't want to touch memory before caches are
    initialized, save the passed in parameter in r10 for the duration of
    cache initialization.
    
    Added warning comments to help enforcing that cache initialization
    code does not touch r10.
    
    BRANCH=storm
    BUG=chrome-os-partner:30623
    TEST=with the rest of the patches applied see the QCA uber-sbl report
         in the coreboot console output.
    
    Change-Id: Ic6a09e8c3cf13ac4f2d12ee91c7ab41bc9aa95da
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: e41584f769eb042604883275b0d0bdfbf5b0d358
    Original-Change-Id: I517a79dc95040326f46f0b80ee4e74bdddde8bf4
    Original-Signed-off-by: Vadim Bendebury <vbendeb at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/255144
    Original-Reviewed-by: Julius Werner <jwerner at chromium.org>
    Original-Commit-Queue: Vadim Bendebury <vbendeb at gmail.com>
---
 src/arch/arm/armv7/bootblock.S                 | 23 +++++++++++++++++++++--
 src/arch/arm/armv7/cpu.S                       |  4 ++++
 src/soc/qualcomm/ipq806x/include/soc/usbl_if.h |  2 ++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/arch/arm/armv7/bootblock.S b/src/arch/arm/armv7/bootblock.S
index b468e15..57d72d0 100644
--- a/src/arch/arm/armv7/bootblock.S
+++ b/src/arch/arm/armv7/bootblock.S
@@ -32,6 +32,16 @@
 #include <arch/asm.h>
 
 .arm
+	/*
+	 * Just in case the maskrom or the vendor basic firmware passes on a
+	 * parameter when calling the bootblock, store it here for handling by C
+	 * code.
+	 */
+	.section .bss, "aw" @nobits
+	.global maskrom_param
+maskrom_param:
+	.word 0
+
 ENTRY(_start)
 	/*
 	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
@@ -45,6 +55,10 @@ ENDPROC(_start)
 
 .thumb
 ENTRY(_thumb_start)
+
+	/* Preserve the maskrom passed value, if any */
+	mov	r10, r0
+
 	bl	arm_init_caches
 
 	/*
@@ -71,9 +85,14 @@ init_stack_loop:
 	cmp	r0, r1
 	bne	init_stack_loop
 
-/* Set stackpointer in internal RAM to call bootblock main() */
 call_bootblock:
-	ldr	sp, =_estack /* Set up stack pointer */
+
+	/* Restore parameter passed in by maskrom/vendor firmware. */
+	ldr	r0, =maskrom_param
+	str	r10, [r0]
+
+	/* Set stackpointer in internal RAM to call bootblock main() */
+	ldr	sp, =_estack
 	ldr	r0,=0x00000000
 	 /*
 	  * The current design of cpu_info places the struct at the top of the
diff --git a/src/arch/arm/armv7/cpu.S b/src/arch/arm/armv7/cpu.S
index b7f245b..6c00f62 100644
--- a/src/arch/arm/armv7/cpu.S
+++ b/src/arch/arm/armv7/cpu.S
@@ -43,6 +43,8 @@
  * through the magic of double subtraction. It's quite ingenius, really.
  * Takes care to only use r0-r3 and ip so it's pefectly ABI-compatible without
  * needing to write to memory.
+ *
+ * THIS FUNCTION MUST PRESERVE THE VALUE OF r10
  */
 
 .macro	dcache_apply_all crm
@@ -109,6 +111,8 @@
  * known state regarding caches/SCTLR. Completely cleans and invalidates
  * icache/dcache, disables MMU and dcache (if active), and enables unaligned
  * accesses, icache and branch prediction (if inactive). Clobbers r4 and r5.
+ *
+ * THIS FUNCTION MUST PRESERVE THE VALUE OF r10
  */
 ENTRY(arm_init_caches)
 	/* r4: SCTLR, return address: r5 (stay valid for the whole function) */
diff --git a/src/soc/qualcomm/ipq806x/include/soc/usbl_if.h b/src/soc/qualcomm/ipq806x/include/soc/usbl_if.h
index eaa96ff..3bbf023 100644
--- a/src/soc/qualcomm/ipq806x/include/soc/usbl_if.h
+++ b/src/soc/qualcomm/ipq806x/include/soc/usbl_if.h
@@ -62,4 +62,6 @@ typedef struct {
 #define UBER_SBL_SHARED_INFO_START_MAGIC	0x5552504d // URPM
 #define UBER_SBL_SHARED_INFO_END_MAGIC		0x554b5254 // UKRT
 
+extern uber_sbl_shared_info *maskrom_param;
+
 #endif