[U-Boot] [PATCH v4 01/18] arm: boot0 hook: move boot0 hook before '_start'
Philipp Tomsich
philipp.tomsich at theobroma-systems.com
Fri Oct 6 19:28:50 UTC 2017
The boot0 hook on ARM does not insert its payload before the vector
table. This is both a mismatch with thec comment above it and
contradict usage of the boot0 hook on ARM64.
To fix this (and unify the semantics for ARM and ARM64), we change the
boot0-hook semantics on ARM to match those on ARM64:
(1) if a boot0-hook is present it is inserted at the start of
the image
(2) if a boot0-hook is present, emitting the ARM vector table
(and the _start) symbol are suppressed in vectors.S and
the boot0-hook has full control over where and when it
wants to emit these
Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
---
Changes in v4: None
Changes in v3: None
Changes in v2: None
arch/arm/include/asm/arch-rockchip/boot0.h | 1 -
arch/arm/lib/vectors.S | 54 +++++++++++++++++++-----------
2 files changed, 35 insertions(+), 20 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/boot0.h b/arch/arm/include/asm/arch-rockchip/boot0.h
index 72d264b..455d842 100644
--- a/arch/arm/include/asm/arch-rockchip/boot0.h
+++ b/arch/arm/include/asm/arch-rockchip/boot0.h
@@ -1,4 +1,3 @@
-
/*
* Copyright 2017 Theobroma Systems Design und Consulting GmbH
*
diff --git a/arch/arm/lib/vectors.S b/arch/arm/lib/vectors.S
index 1019091..9cb0d2e 100644
--- a/arch/arm/lib/vectors.S
+++ b/arch/arm/lib/vectors.S
@@ -16,6 +16,22 @@
#include <config.h>
/*
+ * A macro to allow insertion of an ARM exception vector either
+ * for the non-boot0 case or by a boot0-header.
+ */
+ .macro ARM_VECTORS
+ b reset
+ ldr pc, _undefined_instruction
+ ldr pc, _software_interrupt
+ ldr pc, _prefetch_abort
+ ldr pc, _data_abort
+ ldr pc, _not_used
+ ldr pc, _irq
+ ldr pc, _fiq
+ .endm
+
+
+/*
*************************************************************************
*
* Symbol _start is referenced elsewhere, so make it global
@@ -35,6 +51,23 @@
.section ".vectors", "ax"
+#if defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK)
+/*
+ * Various SoCs need something special and SoC-specific up front in
+ * order to boot, allow them to set that in their boot0.h file and then
+ * use it here.
+ *
+ * To allow a boot0 hook to insert a 'special' sequence after the vector
+ * table (e.g. for the socfpga), the presence of a boot0 hook supresses
+ * the below vector table and assumes that the vector table is filled in
+ * by the boot0 hook. The requirements for a boot0 hook thus are:
+ * (1) defines '_start:' as appropriate
+ * (2) inserts the vector table using ARM_VECTORS as appropriate
+ */
+#include <asm/arch/boot0.h>
+
+#else
+
/*
*************************************************************************
*
@@ -46,28 +79,11 @@
*/
_start:
-
#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
.word CONFIG_SYS_DV_NOR_BOOT_CFG
#endif
-
- b reset
- ldr pc, _undefined_instruction
- ldr pc, _software_interrupt
- ldr pc, _prefetch_abort
- ldr pc, _data_abort
- ldr pc, _not_used
- ldr pc, _irq
- ldr pc, _fiq
-
-#ifdef CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK
-/*
- * Various SoCs need something special and SoC-specific up front in
- * order to boot, allow them to set that in their boot0.h file and then
- * use it here.
- */
-#include <asm/arch/boot0.h>
-#endif
+ ARM_VECTORS
+#endif /* !defined(CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK) */
/*
*************************************************************************
--
2.1.4
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