libpayload: Refactor highlevel CMOS access

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

diff --git a/payloads/libpayload/drivers/options.c b/payloads/libpayload/drivers/options.c
index 51173004271d078aa541868bea97c028082bf25c..61e6cc565f425e31e431d1fa2842a9ca591deb59 100644 (file)
--- a/payloads/libpayload/drivers/options.c
+++ b/payloads/libpayload/drivers/options.c
@@ -30,7 +30,17 @@
 #include <libpayload.h>
 #include <coreboot_tables.h>
 
-static int options_checksum_valid(void)
+struct nvram_accessor *use_nvram = &(struct nvram_accessor) {
+       nvram_read,
+       nvram_write
+};
+
+struct cb_cmos_option_table *get_system_option_table(void)
+{
+       return phys_to_virt(lib_sysinfo.option_table);
+}
+
+static int options_checksum_valid(const struct nvram_accessor *nvram)
 {
        int i;
        int range_start = lib_sysinfo.cmos_range_start / 8;
@@ -39,16 +49,36 @@ static int options_checksum_valid(void)
        u16 checksum = 0, checksum_old;
 
        for(i = range_start; i <= range_end; i++) {
-               checksum += nvram_read(i);
+               checksum += nvram->read(i);
        }
-       checksum = (~checksum)&0xffff;
 
-       checksum_old = ((nvram_read(checksum_location)<<8) | nvram_read(checksum_location+1));
+       checksum_old = ((nvram->read(checksum_location)<<8) | nvram->read(checksum_location+1));
 
        return (checksum_old == checksum);
 }
 
-static int get_cmos_value(u32 bitnum, u32 len, void *valptr)
+void fix_options_checksum_with(const struct nvram_accessor *nvram)
+{
+       int i;
+       int range_start = lib_sysinfo.cmos_range_start / 8;
+       int range_end = lib_sysinfo.cmos_range_end / 8;
+       int checksum_location = lib_sysinfo.cmos_checksum_location / 8;
+       u16 checksum = 0;
+
+       for(i = range_start; i <= range_end; i++) {
+               checksum += nvram->read(i);
+       }
+
+       nvram->write((checksum >> 8), checksum_location);
+       nvram->write((checksum & 0xff), checksum_location + 1);
+}
+
+void fix_options_checksum(void)
+{
+       fix_options_checksum_with(use_nvram);
+}
+
+static int get_cmos_value(const struct nvram_accessor *nvram, u32 bitnum, u32 len, void *valptr)
 {
        u8 *value = (u8 *)valptr;
        int offs = 0;
@@ -61,7 +91,7 @@ static int get_cmos_value(u32 bitnum, u32 len, void *valptr)
 
        /* Handle single byte or less */
        if(len <= 8) {
-               reg8 = nvram_read(addr);
+               reg8 = nvram->read(addr);
                reg8 >>= bit;
                value[0] = reg8 & ((1 << len) -1);
                return 0;
@@ -70,15 +100,43 @@ static int get_cmos_value(u32 bitnum, u32 len, void *valptr)
        /* When handling more than a byte, copy whole bytes */
        while (len > 0) {
                len -= 8;
-               value[offs++]=nvram_read(addr++);
+               value[offs++]=nvram->read(addr++);
        }
 
        return 0;
 }
 
-int get_option(void *dest, char *name)
+static int set_cmos_value(const struct nvram_accessor *nvram, u32 bitnum, u32 len, void *valptr)
+{
+       u8 *value = (u8 *)valptr;
+       int offs = 0;
+       u32 addr, bit;
+       u8 reg8;
+
+       /* Convert to byte borders */
+       addr=(bitnum / 8);
+       bit=(bitnum % 8);
+
+       /* Handle single byte or less */
+       if (len <= 8) {
+               reg8 = nvram->read(addr);
+               reg8 &= ~(((1 << len) - 1) << bit);
+               reg8 |= (value[0] & ((1 << len) - 1)) << bit;
+               nvram->write(reg8, addr);
+               return 0;
+       }
+
+       /* When handling more than a byte, copy whole bytes */
+       while (len > 0) {
+               len -= 8;
+               nvram->write(value[offs++], addr++);
+       }
+
+       return 0;
+}
+
+static struct cb_cmos_entries *lookup_cmos_entry(struct cb_cmos_option_table *option_table, char *name)
 {
-       struct cb_cmos_option_table *option_table = phys_to_virt(lib_sysinfo.option_table);
        struct cb_cmos_entries *cmos_entry;
        int len = strnlen(name, CMOS_MAX_NAME_LENGTH);
 
@@ -89,15 +147,50 @@ int get_option(void *dest, char *name)
                cmos_entry = (struct cb_cmos_entries*)((unsigned char *)cmos_entry + cmos_entry->size)) {
                if (memcmp((const char*)cmos_entry->name, name, len))
                        continue;
-               if(get_cmos_value(cmos_entry->bit, cmos_entry->length, dest))
+               return cmos_entry;
+       }
+
+       printf("ERROR: No such CMOS option (%s)\n", name);
+       return NULL;
+}
+
+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);
+       if (cmos_entry) {
+               if(get_cmos_value(nvram, cmos_entry->bit, cmos_entry->length, dest))
                        return 1;
 
-               if(!options_checksum_valid())
+               if(!options_checksum_valid(nvram))
                        return 1;
 
                return 0;
        }
+       return 1;
+}
 
-       printf("ERROR: No such CMOS option (%s)\n", name);
+int get_option_from(struct cb_cmos_option_table *option_table, void *dest, char *name)
+{
+       return get_option_with(use_nvram, option_table, dest, name);
+}
+
+int get_option(void *dest, char *name)
+{
+       return get_option_from(get_system_option_table(), dest, name);
+}
+
+int set_option_with(const struct nvram_accessor *nvram, struct cb_cmos_option_table *option_table, void *value, char *name)
+{
+       struct cb_cmos_entries *cmos_entry = lookup_cmos_entry(option_table, name);
+       if (cmos_entry) {
+               set_cmos_value(nvram, cmos_entry->bit, cmos_entry->length, value);
+               fix_options_checksum_with(nvram);
+               return 0;
+       }
        return 1;
 }
+
+int set_option(void *value, char *name)
+{
+       return set_option_with(use_nvram, get_system_option_table(), value, name);
+}