[U-Boot] [RFC] Reserve ATF memory on Marvell Armdada 3700/7K/8K

[Alexander Graf]

On 31.03.18 16:13, Mark Kettenis wrote:
> Currently U-Boot doesn't make any effort to reserve the memory used by
> ARM Trusted Firmware on these platforms.  The result is that the
> memory is listed as available in the EFI memory map.  And as soon as a
> loaded kernel tries to use this memory things explode.  I've seen this
> with the OpenBSD kernel.  But I totally expect a Linux kernel to
> suffer the same fate.
> 
> I'm currently using the diff below, but it is not entirely clear to me
> if arch_early_init_r() is the appropriate place to do this.  I'm also
> wondering whether the block should also be marked as reserved in the
> FDT using fdt_add_mem_rsv().  If the latter is required this probably
> needs to be done by ft_board_setup() or ft_system_setup().
> 
> The address and size of the region have been taken from Marvell's ATF
> fork at
> 
>   https://github.com/MarvellEmbeddedProcessors/atf-marvell
> 
> The memory layout is defined in
> 
>   plat/marvell/a8k/common/include/platform_def.h
> 
> where there are lots of defines and a diagram that attempt to describe
> the memory.  It is not entirely obvious to me what part needs to be
> reserved.  But 0x0400000-0x04200000 works.
> 
> 
> 
> 
> diff --git a/arch/arm/mach-mvebu/arm64-common.c b/arch/arm/mach-mvebu/arm64-common.c
> index 3c84043a2c..895cd2852f 100644
> --- a/arch/arm/mach-mvebu/arm64-common.c
> +++ b/arch/arm/mach-mvebu/arm64-common.c
> @@ -95,5 +95,11 @@ int arch_early_init_r(void)
>  	pci_init();
>  #endif
>  
> +#ifdef CONFIG_EFI_LOADER
> +	/* Reserve trusted SRAM section */
> +	efi_add_memory_map(0x04000000, 0x00200000 >> EFI_PAGE_SHIFT,
> +			   EFI_RESERVED_MEMORY_TYPE, false);

I also forgot to comment here. 2MB is probably not enough:


https://github.com/MarvellEmbeddedProcessors/atf-marvell/blob/atf-v1.3-armada-17.10/plat/marvell/a8k/common/include/platform_def.h#L110

That sounds more like it should span 65MB (PLAT_MARVELL_TRUSTED_ROM_SIZE
plus 0x100000).

Looking at what edk2 does, it seems to use the same range as you:


https://github.com/MarvellEmbeddedProcessors/edk2-open-platform/blob/marvell-armada-wip/Platforms/Marvell/Armada/Armada.dsc.inc#L347

So let's also CC Marcin :). Maybe his range is too short!


Alex