[vdr] Re: NVRAM WakeUp

[Patrick GUENEAU <pgueneau@wanadoo.fr>]

Hello,

i have found a program which is the simplest way to read and (maybe)
write into bios nvram.

It is a program written by Paul Gortmaker ; the whole package is called
bios-cmos utilities
(I can't remember from where i downloaded it).

I made some little changes to simplify dump output.
The main point is that you can see nvram including the lower part that
/dev/nvram cannot manage wihout changing kernel source. 


Here is the simple code :

-------------------------------------------------------------------
/*
 *
 *      A quick hack to dump the CMOS RAM values from 0x0 to 0x7f. Note
that
 *      some CMOS are only 0x40 in size, so edit accordingly. Released
to
 *      the public under the terms and conditions of the Gnu General
Public
 *      License (GPL) included herein by reference.
 *
 *      Compile with:
 *               gcc -s -N -Wall -O cmosdump.c -o cmosdump
 *
 *                                      Paul Gortmaker          07/95
 */

#define CMOS_SIZE 0x80

#include <stdio.h>
#include <asm/io.h>
#include <unistd.h>
#include <errno.h>

/*
 * <linux/rtc.h>  was <linux/mc146818rtc.h> on kernels prior to 2.2.19,
so
 * just define CMOS_READ/WRITE here independently and avoid the hassle.
 */

#define RTC_PORT(x)     (0x70 + (x))
#define CMOS_READ(addr) ({ \
outb_p((addr),RTC_PORT(0)); \
inb_p(RTC_PORT(1)); \
})
#define CMOS_WRITE(val, addr) ({ \
outb_p((addr),RTC_PORT(0)); \
outb_p((val),RTC_PORT(1)); \
})


void main(void) {

unsigned short addr, val;

val= iopl(3);
if (val) {
        perror("iopl");
        exit(errno);
}

printf("Addr:\tHex\tDec.\tBinary\n");

for (addr = 0; addr < CMOS_SIZE; addr++) {
        val = CMOS_READ(addr);
        if ( (addr%16) == 0)
          printf("\n0x%.4x:",addr);
        printf(" 0x%.2x", val);
}
printf("\n");

iopl(0);

} /*end*/
-------------------------------------------------------------------


my 2 cents
Patrick.