In the previous commit, two efi-related contexts were introduced.
With this patch, EFI variables implementation will be modified to support volatile/non-volatile attribute properly in such away as UEFI specification expects; If a variable is non-volatile and modified, its value will be updated in backing storage immediately and preserved across reboot. If volatile, it will be lost after reboot.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- lib/efi_loader/efi_variable.c | 91 ++++++++++++++++++++++++++++++++--- 1 file changed, 83 insertions(+), 8 deletions(-)
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 6687b69a400d..18b9e9e5d9f5 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -185,7 +185,9 @@ efi_status_t EFIAPI efi_get_variable(u16 *variable_name,
EFI_PRINT("get '%s'\n", native_name);
- val = env_get(native_name); + val = env_get(ctx_efi, native_name); + if (!val) + val = env_get(ctx_efi_volatile, native_name); free(native_name); if (!val) return EFI_EXIT(EFI_NOT_FOUND); @@ -388,12 +390,48 @@ efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size, efi_cur_variable = NULL;
snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_.*"); - list_len = hexport_r(&env_htab, '\n', + list_len = hexport_r(ctx_efi->htab, '\n', H_MATCH_REGEX | H_MATCH_KEY, &efi_variables_list, 0, 1, regexlist); /* 1 indicates that no match was found */ - if (list_len <= 1) - return EFI_EXIT(EFI_NOT_FOUND); + if (list_len <= 1) { + list_len = hexport_r(ctx_efi_volatile->htab, '\n', + H_MATCH_REGEX | H_MATCH_KEY, + &efi_variables_list, 0, 1, + regexlist); + + if (list_len <= 1) + return EFI_EXIT(EFI_NOT_FOUND); + } else { + char *list_volatile, *list_tmp; + size_t total_len; + + list_volatile = NULL; + total_len = list_len; + list_len = hexport_r(ctx_efi_volatile->htab, '\n', + H_MATCH_REGEX | H_MATCH_KEY, + &list_volatile, 0, 1, + regexlist); + + /* concatenate two lists */ + if (list_len > 1) { + total_len += list_len - 1; + list_tmp = efi_variables_list; + + efi_variables_list = malloc(total_len); + if (efi_variables_list) { + strcpy(efi_variables_list, list_tmp); + strcat(efi_variables_list, + list_volatile); + } + + free(list_tmp); + free(list_volatile); + + if (!efi_variables_list) + return EFI_EXIT(EFI_OUT_OF_RESOURCES); + } + }
variable = efi_variables_list; } @@ -424,8 +462,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_uintn_t data_size, const void *data) { char *native_name = NULL, *val = NULL, *s; + struct env_context *ctx; + u32 attr, non_volatile; efi_status_t ret = EFI_SUCCESS; - u32 attr;
EFI_ENTRY(""%ls" %pUl %x %zu %p", variable_name, vendor, attributes, data_size, data); @@ -447,12 +486,17 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
if ((data_size == 0) || !(attributes & ACCESS_ATTR)) { /* delete the variable: */ - env_set(native_name, NULL); + env_set(ctx_efi, native_name, NULL); ret = EFI_SUCCESS; goto out; }
- val = env_get(native_name); + if (attributes & EFI_VARIABLE_NON_VOLATILE) + ctx = ctx_efi; + else + ctx = ctx_efi_volatile; + + val = env_get(ctx, native_name); if (val) { parse_attr(val, &attr);
@@ -485,6 +529,7 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, * store attributes * TODO: several attributes are not supported */ + non_volatile = (attributes & EFI_VARIABLE_NON_VOLATILE); attributes &= (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS); @@ -512,7 +557,9 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
EFI_PRINT("setting: %s=%s\n", native_name, val);
- if (env_set(native_name, val)) + if (env_set(ctx, native_name, val)) + ret = EFI_DEVICE_ERROR; + else if (non_volatile && env_save(ctx)) ret = EFI_DEVICE_ERROR;
out: @@ -619,5 +666,33 @@ void efi_variables_boot_exit_notify(void) */ efi_status_t efi_init_variables(void) { + int ret; + + /* + * Volatile variables: + * Context for volatile variables has no backing storage + */ + ret = env_ctx_init(ctx_efi_volatile); + if (ret) { + printf("Initializing efi variables(volatile) failed\n"); + + return EFI_DEVICE_ERROR; + } + + /* Non-Volatile variables */ + ret = env_ctx_init(ctx_efi); + if (ret) { + printf("Initializing efi variables failed\n"); + + return EFI_DEVICE_ERROR; + } + + ret = env_load(ctx_efi); + if (ret && ret != -ENODEV) { + printf("Loading efi variables failed\n"); + + return EFI_DEVICE_ERROR; + } + return EFI_SUCCESS; }