[PATCH v3 6/8] ARM: tegra: Always boot CPU in ARM-mode
From: Dmitry Osipenko <digetx@gmail.com>
Date: 2018-08-30 18:05:46
Also in:
linux-arm-kernel, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
CPU always jumps into reset handler in ARM-mode from the Trusted Foundations firmware, hence let's make CPU to always jump into kernel in ARM-mode regardless of the firmware presence to support. This is required to make Thumb-2 kernel working with the Trusted Foundations firmware on Tegra30. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- arch/arm/mach-tegra/reset-handler.S | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index a9f13230da2f..555c652f5a07 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S@@ -20,6 +20,7 @@ #include <soc/tegra/flowctrl.h> #include <soc/tegra/fuse.h> +#include <asm/assembler.h> #include <asm/asm-offsets.h> #include <asm/cache.h>
@@ -112,10 +113,20 @@ ENTRY(__tegra_cpu_reset_handler_start) * NOTE: This code is copied to IRAM. All code and data accesses * must be position-independent. */ - + .arm .align L1_CACHE_SHIFT ENTRY(__tegra_cpu_reset_handler) + /* + * Tegra30 ignores first bit of the reset vector and always jumps + * into kernel in .ARM mode from the firmware, hence force the mode + * switch if kernel is compiled in Thumb-2. + */ + THUMB( badr r0, 1f ) + THUMB( bx r0 ) + THUMB( .thumb ) + THUMB( 1: ) + cpsid aif, 0x13 @ SVC mode, interrupts disabled tegra_get_soc_id TEGRA_APB_MISC_BASE, r6
@@ -215,7 +226,7 @@ __no_cpu0_chk: ldr lr, [r12, #RESET_DATA(STARTUP_SECONDARY)] cmp lr, #0 bleq __die @ no secondary startup handler - bx lr + ret lr #endif /*
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2.18.0