[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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