#include <stdint.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define MSR_DIVIL_LBAR_FLSH0	0x51400010	/* Flash Chip Select 0 */
#define MSR_DIVIL_LBAR_FLSH1	0x51400011	/* Flash Chip Select 1 */
#define MSR_DIVIL_LBAR_FLSH2	0x51400012	/* Flash Chip Select 2 */
#define MSR_DIVIL_LBAR_FLSH3	0x51400013	/* Flash Chip Select 3 */

#define MSR_DIVIL_BALL_OPTS	0x51400015
#define PIN_OPT_IDE		(1ULL<<0)	/* 0 for flash, 1 for IDE */

#define MSR_NANDF_DATA		0x5140001B
#define MSR_NANDF_CTL		0x5140001C

/* Intended value for LBAR_FLSH0: 4KiB, enabled, MMIO, NAND, @0x20000000 */
#define SET_FLSH0 0xFFFFF00720000000ULL

int main(int argc, char **argv)
{
	int fd = open("/dev/cpu/0/msr", O_RDWR);
	uint64_t val;

	if (fd < 0) {
		int i;

		perror("Opening /dev/cpu/0/msr");
		printf("Trying to load 'msr' module...\n");
		system("modprobe msr");
		/* Ick. Might take a while for udev to create the device node... */
		for (i=0; i<10; i++) {
			fd = open("/dev/cpu/0/msr", O_RDWR);
			if (fd >= 0)
				goto opened;
			sleep(1);
		}
		return 1;
	}
 opened:
	if (pread(fd, &val, sizeof(val), MSR_DIVIL_LBAR_FLSH0) != sizeof(val)) {
		printf("Read MSR_DIVIL_LBAR_FLSH0 failed\n");
		close(fd);
		return 1;
	}

	if ( ((val >> 32) & 7) != 7) {
		printf("MSR_DIVIL_LBAR_FLSH0 was %016llx, fixing...\n", val);
		val = SET_FLSH0;
		if (pwrite(fd, &val, sizeof(val), MSR_DIVIL_LBAR_FLSH0) != sizeof(val)) {
			printf("Write MSR_DIVIL_LBAR_FLSH0 failed\n");
			close(fd);
			return 1;
		}
		if (pread(fd, &val, sizeof(val), MSR_DIVIL_LBAR_FLSH0) != sizeof(val)) {
			printf("Read MSR_DIVIL_LBAR_FLSH0 failed\n");
			close(fd);
			return 1;
		}
	}

	printf("MSR_DIVIL_LBAR_FLSH0 is %016llx\n", val);


	if (pread(fd, &val, sizeof(val), MSR_DIVIL_BALL_OPTS) != sizeof(val)) {
		printf("Read MSR_DIVIL_BALL_OPTS failed\n");
		close(fd);
		return 1;
	}
	if (val & PIN_OPT_IDE) {
		printf("MSR_DIVIL_BALL_OPTS was %016llx, fixing...\n", val);
		val &= ~PIN_OPT_IDE;

		if (pwrite(fd, &val, sizeof(val), MSR_DIVIL_BALL_OPTS) != sizeof(val)) {
			printf("Write MSR_DIVIL_BALL_OPTS failed\n");
			close(fd);
			return 1;
		}
		if (pread(fd, &val, sizeof(val), MSR_DIVIL_BALL_OPTS) != sizeof(val)) {
			printf("Read MSR_DIVIL_BALL_OPTS failed\n");
			close(fd);
			return 1;
		}
	}
	printf("MSR_DIVIL_BALL_OPTS is %016llx\n", val);


	if (pread(fd, &val, sizeof(val), MSR_NANDF_DATA) != sizeof(val)) {
		printf("Read MSR_NANDF_DATA failed\n");
		close(fd);
		return 1;
	}
	if (val != 0x01110111ULL) {
		printf("MSR_NANDF_DATA was %016llx, fixing...\n", val);
		val = 0x01110111ULL;

		if (pwrite(fd, &val, sizeof(val), MSR_NANDF_DATA) != sizeof(val)) {
			printf("Write MSR_NANDF_DATA failed\n");
			close(fd);
			return 1;
		}
		if (pread(fd, &val, sizeof(val), MSR_NANDF_DATA) != sizeof(val)) {
			printf("Read MSR_NANDF_DATA failed\n");
			close(fd);
			return 1;
		}
	}
	printf("MSR_NANDF_DATA is %016llx\n", val);

	if (pread(fd, &val, sizeof(val), MSR_NANDF_CTL) != sizeof(val)) {
		printf("Read MSR_NANDF_CTL failed\n");
		close(fd);
		return 1;
	}
	if (val != 0x0111ULL) {
		printf("MSR_NANDF_CTL was %016llx, fixing...\n", val);
		val = 0x0111ULL;

		if (pwrite(fd, &val, sizeof(val), MSR_NANDF_CTL) != sizeof(val)) {
			printf("Write MSR_NANDF_CTL failed\n");
			close(fd);
			return 1;
		}
		if (pread(fd, &val, sizeof(val), MSR_NANDF_CTL) != sizeof(val)) {
			printf("Read MSR_NANDF_CTL failed\n");
			close(fd);
			return 1;
		}
	}
	printf("MSR_NANDF_CTL is %016llx\n", val);
}