There are several implementations of this function in the tree.
Add a central version in grub-core/efi/mm.c.
Taken from grub-core/loader/i386/linux.c, changing some hard-coded constants
to use macros from efi/memory.h.
Signed-off-by: Leif Lindholm <leif.lindh...@linaro.org>
---
grub-core/kern/efi/mm.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
include/grub/efi/efi.h | 1 +
2 files changed, 48 insertions(+)
diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
index ac2a4c556..8795aa1e0 100644
--- a/grub-core/kern/efi/mm.c
+++ b/grub-core/kern/efi/mm.c
@@ -218,6 +218,53 @@ 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)
+{
+ static grub_efi_uintn_t mmap_size = 0;
+
+ if (mmap_size != 0)
+ return mmap_size;
+
+ mmap_size = 1 * GRUB_EFI_PAGE_SIZE;
+ while (1)
+ {
+ int ret;
+ grub_efi_memory_descriptor_t *mmap;
+ grub_efi_uintn_t desc_size;
+ grub_efi_uintn_t cur_mmap_size = mmap_size;
+
+ mmap = grub_malloc (cur_mmap_size);
+ if (! mmap)
+ return 0;
+
+ ret = grub_efi_get_memory_map (&cur_mmap_size, mmap, 0, &desc_size, 0);
+ grub_free (mmap);
+
+ if (ret < 0)
+ {
+ grub_error (GRUB_ERR_IO, "cannot get memory map");
+ return 0;
+ }
+ else if (ret > 0)
+ break;
+
+ if (mmap_size < cur_mmap_size)
+ mmap_size = cur_mmap_size;
+ mmap_size += GRUB_EFI_PAGE_SIZE;
+ }
+
+ /* Increase the size a bit for safety, because GRUB allocates more on
+ later, and EFI itself may allocate more. */
+ mmap_size += 3 * GRUB_EFI_PAGE_SIZE;
+
+ mmap_size = ALIGN_UP (mmap_size, GRUB_EFI_PAGE_SIZE);
+ return mmap_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 3fa082816..8f1f36c8c 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -49,6 +49,7 @@ void *
EXPORT_FUNC(grub_efi_allocate_any_pages) (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,
--
2.11.0
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