efi_loader: set CapsuleMax from CONFIG_EFI_CAPSULE_MAX
Adds CONFIG_EFI_CAPSULE_MAX to configure the max index value used in
EFI capsule reports. Prior to this change is the hard coded value was
65535 which would exceed available storage for variables. Now the
default value is 15 which should work fine with most systems.
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index c05a54d..c5835e6 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -226,6 +226,14 @@
Select this option if you want to enable capsule
authentication
+config EFI_CAPSULE_MAX
+ int "Max value for capsule index"
+ default 15
+ range 0 65535
+ help
+ Select the max capsule index value used for capsule report
+ variables. This value is used to create CapsuleMax variable.
+
config EFI_DEVICE_PATH_TO_TEXT
bool "Device path to text protocol"
default y
diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index 0997cd2..d5d3ede 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -45,17 +45,7 @@
static struct efi_file_handle *bootdev_root;
#endif
-/**
- * get_last_capsule - get the last capsule index
- *
- * Retrieve the index of the capsule invoked last time from "CapsuleLast"
- * variable.
- *
- * Return:
- * * > 0 - the last capsule index invoked
- * * 0xffff - on error, or no capsule invoked yet
- */
-static __maybe_unused unsigned int get_last_capsule(void)
+static __maybe_unused unsigned int get_capsule_index(const u16 *variable_name)
{
u16 value16[11]; /* "CapsuleXXXX": non-null-terminated */
char value[5];
@@ -65,7 +55,7 @@
int i;
size = sizeof(value16);
- ret = efi_get_variable_int(u"CapsuleLast", &efi_guid_capsule_report,
+ ret = efi_get_variable_int(variable_name, &efi_guid_capsule_report,
NULL, &size, value16, NULL);
if (ret != EFI_SUCCESS || size != 22 ||
u16_strncmp(value16, u"Capsule", 7))
@@ -85,6 +75,35 @@
}
/**
+ * get_last_capsule - get the last capsule index
+ *
+ * Retrieve the index of the capsule invoked last time from "CapsuleLast"
+ * variable.
+ *
+ * Return:
+ * * > 0 - the last capsule index invoked
+ * * 0xffff - on error, or no capsule invoked yet
+ */
+static __maybe_unused unsigned int get_last_capsule(void)
+{
+ return get_capsule_index(u"CapsuleLast");
+}
+
+/**
+ * get_max_capsule - get the max capsule index
+ *
+ * Retrieve the max capsule index value from "CapsuleMax" variable.
+ *
+ * Return:
+ * * > 0 - the max capsule index
+ * * 0xffff - on error, or "CapsuleMax" variable does not exist
+ */
+static __maybe_unused unsigned int get_max_capsule(void)
+{
+ return get_capsule_index(u"CapsuleMax");
+}
+
+/**
* set_capsule_result - set a result variable
* @capsule: Capsule
* @return_status: Return status
@@ -1290,7 +1309,7 @@
{
struct efi_capsule_header *capsule = NULL;
u16 **files;
- unsigned int nfiles, index, i;
+ unsigned int nfiles, index, index_max, i;
efi_status_t ret;
bool capsule_update = true;
bool update_status = true;
@@ -1299,6 +1318,7 @@
if (check_run_capsules() != EFI_SUCCESS)
return EFI_SUCCESS;
+ index_max = get_max_capsule();
index = get_last_capsule();
/*
@@ -1317,7 +1337,7 @@
/* Launch capsules */
for (i = 0, ++index; i < nfiles; i++, index++) {
log_debug("Applying %ls\n", files[i]);
- if (index > 0xffff)
+ if (index > index_max)
index = 0;
ret = efi_capsule_read_file(files[i], &capsule);
if (ret == EFI_SUCCESS) {
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index 69aaefa..58d4e13 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -130,12 +130,17 @@
efi_status_t ret = EFI_SUCCESS;
if (IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)) {
+ u16 var_name16[12];
+
+ efi_create_indexed_name(var_name16, sizeof(var_name16),
+ "Capsule", CONFIG_EFI_CAPSULE_MAX);
+
ret = efi_set_variable_int(u"CapsuleMax",
&efi_guid_capsule_report,
EFI_VARIABLE_READ_ONLY |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
- 22, u"CapsuleFFFF", false);
+ 22, var_name16, false);
if (ret != EFI_SUCCESS)
printf("EFI: cannot initialize CapsuleMax variable\n");
}