efi_loader: Add OS notifications for SetVariable at runtime
Previous patches enable SetVariable at runtime using a volatile storage
backend using EFI_RUNTIME_SERVICES_DATA allocared memory. Since there's
no recommendation from the spec on how to notify the OS, add a volatile
EFI variable that contains the filename relative to the ESP. OS'es
can use that file and update it at runtime
$~ efivar -p -n b2ac5fc9-92b7-4acd-aeac-11e818c3130c-RTStorageVolatile
GUID: b2ac5fc9-92b7-4acd-aeac-11e818c3130c
Name: "RTStorageVolatile"
Attributes:
Boot Service Access
Runtime Service Access
Value:
00000000 75 62 6f 6f 74 65 66 69 2e 76 61 72 00 |ubootefi.var. |
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index bb51c02..69442f4 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -159,6 +159,10 @@
#define EFICONFIG_AUTO_GENERATED_ENTRY_GUID \
EFI_GUID(0x8108ac4e, 0x9f11, 0x4d59, \
0x85, 0x0e, 0xe2, 0x1a, 0x52, 0x2c, 0x59, 0xb2)
+#define U_BOOT_EFI_RT_VAR_FILE_GUID \
+ EFI_GUID(0xb2ac5fc9, 0x92b7, 0x4acd, \
+ 0xae, 0xac, 0x11, 0xe8, 0x18, 0xc3, 0x13, 0x0c)
+
/* Use internal device tree when starting UEFI application */
#define EFI_FDT_USE_INTERNAL NULL