From 97d5c7a77e39ab96a2a6137de0e35dd6e3f38325 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Sat, 24 Oct 2015 04:43:31 +0900 Subject: Documentation: EXYNOS: Update bootloader interface on exynos542x Update the documentation about: 1. Usage of PMU_SPARE2 register. Bootloaders on Exynos542x-based boards often use the register PMU_SPARE2 (0x908) in the same way as on Exynos3250: as a indicator the secondary CPU was booted on. The bootloader will set this value to non-zero, after sucessfull power up of secondary CPU. In the same time this booted CPU will stuck (spin) waiting for software reset. 2. Exynos542x entry address for secondary CPU boot up after system suspend (with MCPM enabled and in non-secure mode). See arch/arm/mach-exynos/mcpm-exynos.c for source code. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Kukjin Kim --- Documentation/arm/Samsung/Bootloader-interface.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'Documentation/arm') diff --git a/Documentation/arm/Samsung/Bootloader-interface.txt b/Documentation/arm/Samsung/Bootloader-interface.txt index df8d4fb85939..ed494ac0beb2 100644 --- a/Documentation/arm/Samsung/Bootloader-interface.txt +++ b/Documentation/arm/Samsung/Bootloader-interface.txt @@ -19,7 +19,7 @@ executing kernel. Address: sysram_ns_base_addr Offset Value Purpose ============================================================================= -0x08 exynos_cpu_resume_ns System suspend +0x08 exynos_cpu_resume_ns, mcpm_entry_point System suspend 0x0c 0x00000bad (Magic cookie) System suspend 0x1c exynos4_secondary_startup Secondary CPU boot 0x1c + 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot @@ -56,7 +56,8 @@ Offset Value Purpose Address: pmu_base_addr Offset Value Purpose ============================================================================= -0x0908 Non-zero (only Exynos3250) Secondary CPU boot up indicator +0x0908 Non-zero Secondary CPU boot up indicator + on Exynos3250 and Exynos542x 4. Glossary -- cgit v1.2.3