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); +#endif + return 0; }