S2 Loader app

/* Sample code to access our char device */

#include <stdio.h>
#include <unistd.h>
#include <linux/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>

/* Greybus S2 Loader Load method */
#define GB_S2L_LOAD_METHOD_BOU			0x01
#define GB_S2L_LOAD_METHOD_FLASH		0x02

/* Greybus S2 Loader interface status */
#define GB_S2L_INTERFACE_STATUS_INVALID		0x00 /* Firmware package could not be validated */
#define GB_S2L_INTERFACE_STATUS_INSECURE	0x01 /* Firmware package is valid but insecure */
#define GB_S2L_INTERFACE_STATUS_SECURE		0x02 /* Firmware package is valid and secure */

/* Greybus S2 Loader authorize to boot status */
#define GB_S2L_ATB_STATUS_INVALID		0x00
#define GB_S2L_ATB_STATUS_DENIED		0x01
#define GB_S2L_ATB_STATUS_ALLOWED		0x02

/* IOCTL support */
#define	S2L_IOCTL_BASE		'S'

struct s2l_load_s3_info {
	__u16	version_major;
	__u16	version_minor;
	__u8	load_method; /* Should be set with: GB_S2L_LOAD_METHOD_XXX */
	__u8	status; /* Should be set with: GB_S2L_INTERFACE_STATUS_XXX */
};

#define	S2LIOC_FLASH_AVAILABLE		_IOR(S2L_IOCTL_BASE, 0, __u8)
#define	S2LIOC_LOAD_S3			_IOWR(S2L_IOCTL_BASE, 1, struct s2l_load_s3_info)
#define	S2LIOC_AUTHORIZE_TO_BOOT	_IOW(S2L_IOCTL_BASE, 2, __u8)

const char *cdev = "/dev/char/251:0";
const char buf[] = "Please verify yourself";
char rxbuf[4096];

int main()
{
	int fd, ret;
	__u8 flash = 0, status;
	char buff[80]="";
	struct s2l_load_s3_info s3_info = {
		.version_major = 0,
		.version_minor = 0,
	};

	fd=open(cdev, O_RDWR);
	if (!fd) {
		printf("Failed to open char-dev: %s\n", cdev);
		return -1;
	}

	printf("Opened char-dev: %s\n", cdev);

	/* Authenticate module */
	printf("Authentication request: %s\n", buf);

	ret = write(fd, buf, sizeof(buf));
	if (ret <= 0) {
		printf("Failed to write to char-dev: %s (%d)\n", cdev, ret);
		return -1;
	}

	ret = read(fd, rxbuf, sizeof(rxbuf));
	if (ret <= 0) {
		printf("Failed to read from char-dev: %s (%d)\n", cdev, ret);
		return -1;
	}
	printf("Authentication response: %s\n", rxbuf);

	ret = ioctl(fd, S2LIOC_FLASH_AVAILABLE, &flash);
	if (ret < 0) {
		printf("Failed to get flash-available: %s (%d)\n", cdev, ret);
		return -1;
	}
	printf("S2L Flash Available: %d\n", flash);

	/* Try boot over unipro first */
	s3_info.load_method = GB_S2L_LOAD_METHOD_BOU;
	ret = ioctl(fd, S2LIOC_LOAD_S3, &s3_info);
	if (ret < 0) {
		printf("Failed to load over unipro: %s (%d)\n", cdev, ret);
		return -1;
	}
	printf("BoU done: major: %d, minor: %d, status: %d\n",
		s3_info.version_major, s3_info.version_minor, s3_info.status);

	if (flash) {
		/* Try boot over flash now */
		s3_info.load_method = GB_S2L_LOAD_METHOD_FLASH;
		ret = ioctl(fd, S2LIOC_LOAD_S3, &s3_info);
		if (ret < 0) {
			printf("Failed to load from flash: %s (%d)\n", cdev, ret);
			return -1;
		}
		printf("Flash load done: major: %d, minor: %d, status: %d\n",
			s3_info.version_major, s3_info.version_minor,
			s3_info.status);
	}

	/* Authenticate module */
	status = GB_S2L_ATB_STATUS_ALLOWED;
	ret = ioctl(fd, S2LIOC_AUTHORIZE_TO_BOOT, &status);
	if (ret < 0) {
		printf("Failed to authorize module to boot: %s (%d)\n", cdev, ret);
		return -1;
	}
	printf("S2L Authorized module\n");

	close(fd);
}