/**********************************************************************
**  dump_raw.c
**
**	Download RAW Image to Frame Buffer Memory
**	Version 1.0
**
**  Copyright (C) 2018 H.Poetzl
**
**	This program is free software: you can redistribute it and/or
**	modify it under the terms of the GNU General Public License
**	as published by the Free Software Foundation, either version
**	2 of the License, or (at your option) any later version.
**
**********************************************************************/


#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


static char *cmd_name = NULL;

static uint32_t map_base = 0x18000000;
static uint32_t map_size = 0x08000000;
static uint32_t map_addr = 0x00000000;

static char *dev_mem = "/dev/mem";

#define	NUM_COLS 4096
#define	NUM_ROWS 3072


#define	ERR_WRITE 1

int	write_data(int fd, uint8_t *buf, size_t cnt) {

	while (cnt) {
	    size_t len = write(fd, buf, cnt);

	    if (len < 0)
		return ERR_WRITE;

	    cnt -= len;
	    buf += len;
	}
	return 0;
}


void	load_data(uint8_t *buf, uint64_t *ptr) {
	
	for (unsigned i = 0; i < NUM_COLS/2; i++) {
	    unsigned ce = i * 3;
	    unsigned co = (i + NUM_COLS/2) * 3;
	    uint64_t val = ptr[i];

	    buf[ce + 0] = (val >> 56) & 0xFF;
	    buf[ce + 1] = (val >> 48) & 0xFF;
	    buf[ce + 2] = (val >> 40) & 0xFF;

	    buf[co + 0] = (val >> 32) & 0xFF;
	    buf[co + 1] = (val >> 24) & 0xFF;
	    buf[co + 2] = (val >> 16) & 0xFF;
	}
}


int	main(int argc, char **argv) {
	extern int optind;
	extern char *optarg;
	int c, err_flag = 0;

	#define OPTIONS "hB:S:"
	#define VERSION "1.0"

	cmd_name = argv[0];
	while ((c = getopt(argc, argv, OPTIONS)) != EOF) {
	    switch (c) {
	    case 'h':
		fprintf(stderr,
		    "This is %s " VERSION "\n"
		    "options are:\n"
		    "-h        print this help message\n"
		    "-B <val>  memory mapping base\n"
		    "-S <val>  memory mapping size\n",
		    cmd_name);
		exit(0);
		break;

	    case 'B':
		map_base = strtoll(optarg, NULL, 0);
		break;

	    case 'S':
		map_size = strtoll(optarg, NULL, 0);
		break;

	    default:
		err_flag++;
		break;
	    }
	}

	if (err_flag) {
	    fprintf(stderr,
		"Usage: %s -[" OPTIONS "] [file]\n"
		"%s -h for help.\n",
		cmd_name, cmd_name);
	    exit(1);
	}

	int fd = open(dev_mem, O_RDWR | O_SYNC);
	if (fd == -1) {
	    fprintf(stderr,
		"error opening >%s<.\n%s\n",
		dev_mem, strerror(errno));
	    exit(2);
	}

	if (map_addr == 0)
	    map_addr = map_base;

	void *base = mmap((void *)map_addr, map_size,
	    PROT_READ | PROT_WRITE, MAP_SHARED,
	    fd, map_base);
	if (base == (void *)-1) {
	    fprintf(stderr,
		"error mapping 0x%08X+0x%08X @0x%08X.\n%s\n",
		map_base, map_size, map_addr,
		strerror(errno));
	    exit(2);
	}

	fprintf(stderr,
	    "mapped 0x%08lX+0x%08lX to 0x%08lX.\n",
	    (long unsigned)map_base, (long unsigned)map_size,
	    (long unsigned)base);


	if (argc > optind) {
	    close(1);
	    int fd = open(argv[optind], O_CREAT|O_WRONLY, S_IRUSR);

	    if (fd == -1) {
		fprintf(stderr,
		    "error opening >%s< for writing.\n%s\n",
		    argv[optind], strerror(errno));
		exit(2);
	    }
	}

	uint8_t buf[NUM_COLS*3];
	uint64_t *ptr = base;

	for (unsigned j = 0; j < NUM_ROWS/2; j++) {

	    load_data(buf, ptr);

	    int res = write_data(1, buf, sizeof(buf));
	    if (res == ERR_WRITE) {
		fprintf(stderr,
		    "error writing.\n%s\n",
		    strerror(errno));
		exit(4);
	    }

	    ptr += NUM_COLS/2;
	}

	exit(0);
}