From bad144c60f664a83f5a7d3a014927bffaa2abbf1 Mon Sep 17 00:00:00 2001 From: Leif Lindholm Date: Mon, 9 Jul 2018 18:33:01 +0100 Subject: [PATCH] efi: Add grub_efi_get_ram_base() function for arm64 Since ARM platforms do not have a common memory map, add a helper function that finds the lowest address region with the EFI_MEMORY_WB attribute set in the UEFI memory map. Required for the arm64 efi linux loader to restrict the initrd location to where it will be accessible by the kernel at runtime. Signed-off-by: Leif Lindholm Reviewed-by: Daniel Kiper --- grub-core/kern/efi/mm.c | 31 +++++++++++++++++++++++++++++++ include/grub/efi/efi.h | 3 +++ 2 files changed, 34 insertions(+) diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c index a8e0e4a89..92e9763d2 100644 --- a/grub-core/kern/efi/mm.c +++ b/grub-core/kern/efi/mm.c @@ -633,3 +633,34 @@ grub_efi_mm_init (void) grub_efi_free_pages ((grub_addr_t) memory_map, 2 * BYTES_TO_PAGES (MEMORY_MAP_SIZE)); } + +#if defined (__aarch64__) +grub_err_t +grub_efi_get_ram_base(grub_addr_t *base_addr) +{ + grub_efi_memory_descriptor_t *memory_map, *desc; + grub_efi_uintn_t memory_map_size, desc_size; + int ret; + + memory_map_size = grub_efi_find_mmap_size(); + + memory_map = grub_malloc (memory_map_size); + if (! memory_map) + return GRUB_ERR_OUT_OF_MEMORY; + ret = grub_efi_get_memory_map (&memory_map_size, memory_map, NULL, + &desc_size, NULL); + + if (ret < 1) + return GRUB_ERR_BUG; + + for (desc = memory_map, *base_addr = GRUB_UINT_MAX; + (grub_addr_t) desc < ((grub_addr_t) memory_map + memory_map_size); + desc = NEXT_MEMORY_DESCRIPTOR (desc, desc_size)) + if (desc->attribute & GRUB_EFI_MEMORY_WB) + *base_addr = grub_min (*base_addr, desc->physical_start); + + grub_free(memory_map); + + return GRUB_ERR_NONE; +} +#endif diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h index 1021273c1..57db74b57 100644 --- a/include/grub/efi/efi.h +++ b/include/grub/efi/efi.h @@ -93,6 +93,9 @@ extern void (*EXPORT_VAR(grub_efi_net_config)) (grub_efi_handle_t hnd, #if defined(__arm__) || defined(__aarch64__) void *EXPORT_FUNC(grub_efi_get_firmware_fdt)(void); #endif +#if defined(__aarch64__) +grub_err_t EXPORT_FUNC(grub_efi_get_ram_base)(grub_addr_t *); +#endif grub_addr_t grub_efi_modules_addr (void);