[PATCH] Documentation: ARM: EXYNOS: Update bootloader interface on Exynos542x
Kukjin Kim
kgene at kernel.org
Fri Oct 23 12:39:32 PDT 2015
On 10/23/15 13:19, Krzysztof Kozlowski wrote:
> 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 <k.kozlowski at samsung.com>
> ---
> Documentation/arm/Samsung/Bootloader-interface.txt | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> 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
Applied, thanks.
- Kukjin
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