Currently, if GetMemoryMap API returns EFI_BUFFER_TOO_SMALL, it doesn't set valid values to other parameters, descriptor_size and descriptor_version, except memory_map_size. Some efi applications, however, may use those value; in particular, xen uses descriptor_size to calculate a size of buffer to be allocated.
While UEFI specification is ambiguous in this point, it would be better to address this issue proactively to maximize the compatibility with existing efi applications.
With this patch, for example, xen.efi (and hence linux kernel) can be started via bootefi without modification.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- lib/efi_loader/efi_memory.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c index 89adf2031024..97d90f069a63 100644 --- a/lib/efi_loader/efi_memory.c +++ b/lib/efi_loader/efi_memory.c @@ -627,18 +627,18 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
*memory_map_size = map_size;
- if (provided_map_size < map_size) - return EFI_BUFFER_TOO_SMALL; - - if (!memory_map) - return EFI_INVALID_PARAMETER; - if (descriptor_size) *descriptor_size = sizeof(struct efi_mem_desc);
if (descriptor_version) *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
+ if (provided_map_size < map_size) + return EFI_BUFFER_TOO_SMALL; + + if (!memory_map) + return EFI_INVALID_PARAMETER; + /* Copy list into array */ /* Return the list in ascending order */ memory_map = &memory_map[map_entries - 1];