libpayload: Add access to CMOS images in memory space

[coreboot.git] / src / pc80 / mc146818rtc.c

diff --git a/src/pc80/mc146818rtc.c b/src/pc80/mc146818rtc.c
index d9a3d481e9caf1e3e80887a26482e671d939d4c8..99d670de421d8c950f81baa4d501aac93c1b6100 100644 (file)
--- a/src/pc80/mc146818rtc.c
+++ b/src/pc80/mc146818rtc.c
@@ -1,3 +1,4 @@
+#include <stdint.h>
 #include <console/console.h>
 #include <pc80/mc146818rtc.h>
 #include <boot/coreboot_tables.h>
@@ -80,12 +81,11 @@
 static int rtc_checksum_valid(int range_start, int range_end, int cks_loc)
 {
        int i;
-       unsigned sum, old_sum;
+       u16 sum, old_sum;
        sum = 0;
        for(i = range_start; i <= range_end; i++) {
                sum += cmos_read(i);
        }
-       sum = (~sum)&0x0ffff;
        old_sum = ((cmos_read(cks_loc)<<8) | cmos_read(cks_loc+1))&0x0ffff;
        return sum == old_sum;
 }
@@ -93,12 +93,11 @@ static int rtc_checksum_valid(int range_start, int range_end, int cks_loc)
 static void rtc_set_checksum(int range_start, int range_end, int cks_loc)
 {
        int i;
-       unsigned sum;
+       u16 sum;
        sum = 0;
        for(i = range_start; i <= range_end; i++) {
                sum += cmos_read(i);
        }
-       sum = ~(sum & 0x0ffff);
        cmos_write(((sum >> 8) & 0x0ff), cks_loc);
        cmos_write(((sum >> 0) & 0x0ff), cks_loc+1);
 }
@@ -132,12 +131,14 @@ void rtc_init(int invalid)
        checksum_invalid = !rtc_checksum_valid(PC_CKS_RANGE_START,
                        PC_CKS_RANGE_END,PC_CKS_LOC);
 
+#define CLEAR_CMOS 0
        if (invalid || cmos_invalid || checksum_invalid) {
-               printk(BIOS_WARNING, "RTC:%s%s%s zeroing cmos\n",
+               printk(BIOS_WARNING, "RTC:%s%s%s%s\n",
                        invalid?" Clear requested":"",
                        cmos_invalid?" Power Problem":"",
-                       checksum_invalid?" Checksum invalid":"");
-#if 0
+                       checksum_invalid?" Checksum invalid":"",
+                       CLEAR_CMOS?" zeroing cmos":"");
+#if CLEAR_CMOS
                cmos_write(0, 0x01);
                cmos_write(0, 0x03);
                cmos_write(0, 0x05);
@@ -169,7 +170,7 @@ void rtc_init(int invalid)
        checksum_invalid = !rtc_checksum_valid(LB_CKS_RANGE_START,
                        LB_CKS_RANGE_END,LB_CKS_LOC);
        if(checksum_invalid)
-               printk(BIOS_DEBUG, "Invalid CMOS LB checksum\n");
+               printk(BIOS_DEBUG, "RTC: coreboot checksum invalid\n");
 
        /* Make certain we have a valid checksum */
        rtc_set_checksum(PC_CKS_RANGE_START,
@@ -227,9 +228,10 @@ int get_option(void *dest, const char *name)
        namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
 
        /* find the requested entry record */
-       ct=cbfs_find_file("cmos_layout.bin", CMOS_COMPONENT_CMOS_LAYOUT);
+       ct=cbfs_find_file("cmos_layout.bin", CBFS_COMPONENT_CMOS_LAYOUT);
        if (!ct) {
-               printk(BIOS_ERR, "cmos_layout.bin could not be found. Options are disabled\n");
+               printk(BIOS_ERR, "RTC: cmos_layout.bin could not be found. "
+                                               "Options are disabled\n");
                return(-2);
        }
        ce=(struct cmos_entries*)((unsigned char *)ct + ct->header_length);
@@ -252,4 +254,87 @@ int get_option(void *dest, const char *name)
                return(-4);
        return(0);
 }
+
+static int set_cmos_value(unsigned long bit, unsigned long length, void *vret)
+{
+       unsigned char *ret;
+       unsigned long byte,byte_bit;
+       unsigned long i;
+       unsigned char uchar, mask;
+       unsigned int chksum_update_needed = 0;
+
+       ret = vret;
+       byte = bit / 8;                 /* find the byte where the data starts */
+       byte_bit = bit % 8;             /* find the bit in the byte where the data starts */
+       if(length <= 8) {               /* one byte or less */
+               mask = (1 << length) - 1;
+               mask <<= byte_bit;
+
+               uchar = cmos_read(byte);
+               uchar &= ~mask;
+               uchar |= (ret[0] << byte_bit);
+               cmos_write(uchar, byte);
+               if (byte >= LB_CKS_RANGE_START && byte <= LB_CKS_RANGE_END)
+                       chksum_update_needed = 1;
+       } else {                        /* more that one byte so transfer the whole bytes */
+               if (byte_bit || length % 8)
+                       return -1;
+
+               for(i=0; length; i++, length-=8, byte++)
+                       cmos_write(ret[i], byte);
+                       if (byte >= LB_CKS_RANGE_START && byte <= LB_CKS_RANGE_END)
+                               chksum_update_needed = 1;
+       }
+
+       if (chksum_update_needed) {
+               rtc_set_checksum(LB_CKS_RANGE_START,
+                       LB_CKS_RANGE_END,LB_CKS_LOC);
+       }
+       return 0;
+}
+
+
+int set_option(const char *name, void *value)
+{
+       struct cmos_option_table *ct;
+       struct cmos_entries *ce;
+       unsigned long length;
+       size_t namelen;
+       int found=0;
+
+       /* Figure out how long name is */
+       namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
+
+       /* find the requested entry record */
+       ct=cbfs_find_file("cmos_layout.bin", CBFS_COMPONENT_CMOS_LAYOUT);
+       if (!ct) {
+               printk(BIOS_ERR, "cmos_layout.bin could not be found. Options are disabled\n");
+               return(-2);
+       }
+       ce=(struct cmos_entries*)((unsigned char *)ct + ct->header_length);
+       for(;ce->tag==LB_TAG_OPTION;
+               ce=(struct cmos_entries*)((unsigned char *)ce + ce->size)) {
+               if (memcmp(ce->name, name, namelen) == 0) {
+                       found=1;
+                       break;
+               }
+       }
+       if(!found) {
+               printk(BIOS_DEBUG, "WARNING: No CMOS option '%s'.\n", name);
+               return(-2);
+       }
+
+       length = ce->length;
+       if (ce->config == 's') {
+               length = MAX(strlen((const char *)value) * 8, ce->length - 8);
+               /* make sure the string is null terminated */
+               if ((set_cmos_value(ce->bit + ce->length - 8, 8, &(u8[]){0})))
+                       return (-3);
+       }
+
+       if ((set_cmos_value(ce->bit, length, value)))
+               return (-3);
+
+       return 0;
+}
 #endif /* CONFIG_USE_OPTION_TABLE */