On 17.04.24 12:19, Ilias Apalodimas wrote:
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. |
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
Reviewed-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com
include/efi_loader.h | 4 ++++ lib/efi_loader/efi_runtime.c | 19 ++++++++++++++++--- 2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h index bb51c0281774..69442f4e58de 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -159,6 +159,10 @@ static inline void efi_set_bootdev(const char *dev, const char *devnr, #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
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index dde083b09665..c8f7a88ba8db 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -10,6 +10,7 @@ #include <dm.h> #include <elf.h> #include <efi_loader.h> +#include <efi_variable.h> #include <log.h> #include <malloc.h> #include <rtc.h> @@ -110,6 +111,7 @@ static __efi_runtime_data efi_uintn_t efi_descriptor_size; */ efi_status_t efi_init_runtime_supported(void) {
- const efi_guid_t efi_guid_efi_rt_var_file = U_BOOT_EFI_RT_VAR_FILE_GUID; efi_status_t ret; struct efi_rt_properties_table *rt_table;
@@ -127,9 +129,20 @@ efi_status_t efi_init_runtime_supported(void) EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP | EFI_RT_SUPPORTED_CONVERT_POINTER;
- if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE))
rt_table->runtime_services_supported |=EFI_RT_SUPPORTED_SET_VARIABLE;
if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
ret = efi_set_variable_int(u"RTStorageVolatile",&efi_guid_efi_rt_var_file,EFI_VARIABLE_BOOTSERVICE_ACCESS |EFI_VARIABLE_RUNTIME_ACCESS |EFI_VARIABLE_READ_ONLY,sizeof(EFI_VAR_FILE_NAME),EFI_VAR_FILE_NAME, false);if (ret != EFI_SUCCESS) {log_err("Failed to set RTStorageVolatile\n");return ret;}rt_table->runtime_services_supported |= EFI_RT_SUPPORTED_SET_VARIABLE;}
/*
- This value must be synced with efi_runtime_detach_list