6 files changed, 142 insertions, 2 deletions
diff --git a/payloads/libpayload/Config.in b/payloads/libpayload/Config.in
index 82218ba4b6..dca9e1e4ff 100644
--- a/payloads/libpayload/Config.in
+++ b/payloads/libpayload/Config.in
@@ -68,6 +68,10 @@ config PC_KEYBOARD
        depends VGA_CONSOLE
        default y
 
+config CMOS
+       bool "Support for reading/writing CMOS bytes"
+       default y
+
 endmenu
 
 menu "Build Options"
diff --git a/payloads/libpayload/drivers/Makefile.inc b/payloads/libpayload/drivers/Makefile.inc
index 8a39e4a4dd..08e7150037 100644
--- a/payloads/libpayload/drivers/Makefile.inc
+++ b/payloads/libpayload/drivers/Makefile.inc
@@ -31,3 +31,4 @@
 TARGETS-$(CONFIG_SERIAL_CONSOLE) += drivers/serial.o
 TARGETS-$(CONFIG_VGA_CONSOLE) += drivers/vga.o
 TARGETS-$(CONFIG_PC_KEYBOARD) += drivers/keyboard.o
+TARGETS-$(CONFIG_CMOS) += drivers/cmos.o
diff --git a/payloads/libpayload/drivers/cmos.c b/payloads/libpayload/drivers/cmos.c
new file mode 100644
index 0000000000..c8cd605a0a
--- /dev/null
+++ b/payloads/libpayload/drivers/cmos.c
@@ -0,0 +1,69 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2008 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Datasheet:
+ *  - Name: MC146818: Real-time Clock Plus RAM (RTC)
+ *  - PDF: http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC146818.pdf
+ *  - Order number: MC146818/D
+ */
+
+/*
+ * See also:
+ * http://bochs.sourceforge.net/techspec/CMOS-reference.txt
+ * http://www.bioscentral.com/misc/cmosmap.htm
+ */
+
+#include <libpayload.h>
+
+#define RTC_PORT 0x70
+
+/**
+ * Read a byte from the specified CMOS address.
+ * 
+ * @param addr The CMOS address to read a byte from.
+ * @return The byte at the given CMOS address.
+ */
+u8 cmos_read(u8 addr)
+{
+	outb(addr, RTC_PORT);
+	return inb(RTC_PORT + 1);
+}
+
+/**
+ * Write a byte to the specified CMOS address.
+ * 
+ * @param val The byte to write to CMOS.
+ * @param addr The CMOS address to write to.
+ */
+void cmos_write(u8 val, u8 addr)
+{
+	outb(addr, RTC_PORT);
+	outb(val, RTC_PORT + 1);
+}
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 34258cf49b..6d80004a98 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -41,6 +41,18 @@
 #define MAX(a,b) ((a) > (b) ? (a) : (b))
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
+/* Some CMOS byte definitions */
+#define CMOS_RTC_SECONDS        0
+#define CMOS_RTC_MINUTES        2
+#define CMOS_RTC_HOURS          4
+#define CMOS_RTC_DAY            7
+#define CMOS_RTC_MONTH          8
+#define CMOS_RTC_YEAR           9
+
+/* drivers/cmos.c */
+u8 cmos_read(u8 addr);
+void cmos_write(u8 val, u8 addr);
+
 /* drivers/keyboard.c */
 int keyboard_havechar(void);
 unsigned char keyboard_get_scancode(void);
@@ -87,6 +99,10 @@ void *malloc(size_t size);
 void *calloc(size_t nmemb, size_t size);
 void *realloc(void *ptr, size_t size);
 
+/* libc/lib.c */
+int bcd2dec(int b);
+int dec2bcd(int d);
+
 /* libc/memory.c */
 void *memset(void *s, int c, size_t n);
 void *memcpy(void *dst, const void *src, size_t n);
diff --git a/payloads/libpayload/libc/Makefile.inc b/payloads/libpayload/libc/Makefile.inc
index 2c1ef72564..ee64b60644 100644
--- a/payloads/libpayload/libc/Makefile.inc
+++ b/payloads/libpayload/libc/Makefile.inc
@@ -28,5 +28,4 @@
 ##
 
 TARGETS-y += libc/malloc.o libc/printf.o libc/console.o libc/string.o
-TARGETS-y += libc/memory.o libc/ctype.o
-TARGETS-y += libc/ipchecksum.o
+TARGETS-y += libc/memory.o libc/ctype.o libc/ipchecksum.o libc/lib.o
diff --git a/payloads/libpayload/libc/lib.c b/payloads/libpayload/libc/lib.c
new file mode 100644
index 0000000000..9200455a8a
--- /dev/null
+++ b/payloads/libpayload/libc/lib.c
@@ -0,0 +1,51 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2008 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Convert a number in BCD format to decimal.
+ *
+ * @param b The BCD number.
+ * @return The given BCD number in decimal format.
+ */
+int bcd2dec(int b)
+{
+	return ((b >> 4) & 0x0f) * 10 + (b & 0x0f);
+}
+
+/*
+ * Convert a number in decimal format into the BCD format.
+ *
+ * @param d The decimal number.
+ * @return The given decimal number in BCD format.
+ */
+int dec2bcd(int d)
+{
+	return ((d / 10) << 4) | (d % 10);
+}
+