libpayload: Provide interpretation of CMOS data structures

[coreboot.git] / payloads / libpayload / drivers / options.c

diff --git a/payloads/libpayload/drivers/options.c b/payloads/libpayload/drivers/options.c
index 36d8a9b5b09b9b2044ed4f643d93c7f80d599b8b..33c06596ca7749179cb00eb4473f5bd84061fd9e 100644 (file)
--- a/payloads/libpayload/drivers/options.c
+++ b/payloads/libpayload/drivers/options.c
@@ -171,6 +171,42 @@ static struct cb_cmos_entries *lookup_cmos_entry(struct cb_cmos_option_table *op
        return NULL;
 }
 
+/* Either value or text must be NULL. Returns the field that matches "the other" for a given config_id */
+static struct cb_cmos_enums *lookup_cmos_enum_core(struct cb_cmos_option_table *option_table, int config_id, u8 *value, char *text)
+{
+       struct cb_cmos_entries *cmos_entry;
+       int len = strnlen(text, CMOS_MAX_TEXT_LENGTH);
+
+       /* cmos entries are located right after the option table. Skip them */
+       cmos_entry = (struct cb_cmos_entries*)((unsigned char *)option_table + option_table->header_length);
+       while (cmos_entry->tag == CB_TAG_OPTION)
+               cmos_entry = (struct cb_cmos_entries*)((unsigned char *)cmos_entry + cmos_entry->size);
+
+       /* cmos enums are located after cmos entries. */
+       struct cb_cmos_enums *cmos_enum;
+       for (   cmos_enum = (struct cb_cmos_enums*)cmos_entry;
+               cmos_enum->tag == CB_TAG_OPTION_ENUM;
+               cmos_enum = (struct cb_cmos_enums*)((unsigned char *)cmos_enum + cmos_enum->size)) {
+               if ((cmos_enum->config_id == config_id)
+                  && ((value == NULL) || (cmos_enum->value == *value))
+                  && ((text == NULL) || (memcmp((const char*)cmos_enum->text, text, len)))) {
+                       return cmos_enum;
+               }
+       }
+
+       return NULL;
+}
+
+static struct cb_cmos_enums *lookup_cmos_enum_by_value(struct cb_cmos_option_table *option_table, int config_id, u8 *value)
+{
+       return lookup_cmos_enum_core(option_table, config_id, value, NULL);
+}
+
+static struct cb_cmos_enums *lookup_cmos_enum_by_label(struct cb_cmos_option_table *option_table, int config_id, char *label)
+{
+       return lookup_cmos_enum_core(option_table, config_id, NULL, label);
+}
+
 int get_option_with(const struct nvram_accessor *nvram, struct cb_cmos_option_table *option_table, void *dest, char *name)
 {
        struct cb_cmos_entries *cmos_entry = lookup_cmos_entry(option_table, name);
@@ -211,3 +247,70 @@ int set_option(void *value, char *name)
 {
        return set_option_with(use_nvram, get_system_option_table(), value, name);
 }
+
+int get_option_as_string(const struct nvram_accessor *nvram, struct cb_cmos_option_table *option_table, char **dest, char *name)
+{
+       void *raw;
+       struct cb_cmos_entries *cmos_entry = lookup_cmos_entry(option_table, name);
+       if (!cmos_entry)
+               return 1;
+       int cmos_length = (cmos_entry->length+7)/8;
+
+       /* extra byte to ensure 0-terminated strings */
+       raw = malloc(cmos_length+1);
+       memset(raw, 0, cmos_length+1);
+
+       int ret = get_option_with(nvram, option_table, raw, name);
+
+       struct cb_cmos_enums *cmos_enum;
+       switch (cmos_entry->config) {
+               case 'h':
+                       /* only works on little endian.
+                          26 bytes is enough for a 64bit value in decimal */
+                       *dest = malloc(26);
+                       sprintf(*dest, "%ull", *(u64*)raw);
+                       break;
+               case 's':
+                       *dest = strdup(raw);
+                       break;
+               case 'e':
+                       cmos_enum = lookup_cmos_enum_by_value(option_table, cmos_entry->config_id, (u8*)raw);
+                       *dest = strdup((const char*)cmos_enum->text);
+                       break;
+               default: /* fail */
+                       return 1;
+       }
+       free(raw);
+       return ret;
+}
+
+int set_option_from_string(const struct nvram_accessor *nvram, struct cb_cmos_option_table *option_table, char *value, char *name)
+{
+       void *raw;
+       struct cb_cmos_entries *cmos_entry = lookup_cmos_entry(option_table, name);
+       if (!cmos_entry)
+               return 1;
+
+       struct cb_cmos_enums *cmos_enum;
+       switch (cmos_entry->config) {
+               case 'h':
+                       /* only works on little endian */
+                       raw = malloc(8);
+                       *(u64*)raw = strtoull(value, NULL, 0);
+                       break;
+               case 's':
+                       raw = strdup(value);
+                       break;
+               case 'e':
+                       cmos_enum = lookup_cmos_enum_by_label(option_table, cmos_entry->config_id, value);
+                       raw = malloc(sizeof(u32));
+                       *(u32*)raw = cmos_enum->value;
+                       break;
+               default: /* fail */
+                       return 1;
+       }
+
+       int ret = set_option_with(nvram, option_table, raw, name);
+       free(raw);
+       return ret;
+}