From 6ca50ac741b8c826f953b0905d736006b895f912 Mon Sep 17 00:00:00 2001 From: Leif Lindholm Date: Mon, 9 Jul 2018 18:33:00 +0100 Subject: [PATCH 4/6] efi: Add central copy of grub_efi_find_mmap_size There are several implementations of this function in the tree. Add a central version in grub-core/efi/mm.c. Signed-off-by: Leif Lindholm Reviewed-by: Daniel Kiper --- grub-core/kern/efi/mm.c | 24 ++++++++++++++++++++++++ include/grub/efi/efi.h | 1 + 2 files changed, 25 insertions(+) diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c index 4226f34ec..021d750b6 100644 --- a/grub-core/kern/efi/mm.c +++ b/grub-core/kern/efi/mm.c @@ -315,6 +315,30 @@ grub_efi_finish_boot_services (grub_efi_uintn_t *outbuf_size, void *outbuf, return GRUB_ERR_NONE; } +/* + * To obtain the UEFI memory map, we must pass a buffer of sufficient size + * to hold the entire map. This function returns a sane start value for + * buffer size. + */ +grub_efi_uintn_t +grub_efi_find_mmap_size (void) +{ + grub_efi_uintn_t mmap_size = 0; + grub_efi_uintn_t desc_size; + + if (grub_efi_get_memory_map (&mmap_size, NULL, NULL, &desc_size, 0) < 0) + { + grub_error (GRUB_ERR_IO, "cannot get EFI memory map size"); + return 0; + } + + /* + * Add an extra page, since UEFI can alter the memory map itself on + * callbacks or explicit calls, including console output. + */ + return ALIGN_UP (mmap_size + GRUB_EFI_PAGE_SIZE, GRUB_EFI_PAGE_SIZE); +} + /* Get the memory map as defined in the EFI spec. Return 1 if successful, return 0 if partial, or return -1 if an error occurs. */ int diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h index f68a19de4..e8ae60931 100644 --- a/include/grub/efi/efi.h +++ b/include/grub/efi/efi.h @@ -52,6 +52,7 @@ EXPORT_FUNC(grub_efi_allocate_pages_max) (grub_efi_physical_address_t max, grub_efi_uintn_t pages); void EXPORT_FUNC(grub_efi_free_pages) (grub_efi_physical_address_t address, grub_efi_uintn_t pages); +grub_efi_uintn_t EXPORT_FUNC(grub_efi_find_mmap_size) (void); int EXPORT_FUNC(grub_efi_get_memory_map) (grub_efi_uintn_t *memory_map_size, grub_efi_memory_descriptor_t *memory_map, -- 2.16.4