/*
 * JR-IDE Project
 * - (c) 2017 Alan Hightower
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Temporary program design to facilitate bootstrap on a broken system.
 * It sends a static request to the Pi for 1 of several basic images
 * and writes them to disk
 */

#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>

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

#include <stdio.h>
#include <dos.h>
#include <libgen.h>
#include <conio.h>

#include "rpc.h"
#include "jride.h"
#include "flash_api.h"


volatile uint16_t far *ide_sector;
volatile uint8_t far *ide_window;
volatile uint8_t far *bios_window;


uint16_t sector[63 * 256];

extern void _xfer_sector_in (uint16_t far *dst);
#pragma aux _xfer_sector_in = \
	"push ds" \
	"lds si, dword ptr ide_sector" \
	"mov cx, 0x100" \
	"cld" \
	"rep movsw" \
	"pop ds" \
	parm [di es] \
	modify [si es di cx];


extern uint16_t get_ds(void);
#pragma aux get_ds = \
    "mov ax,ds" \
    value [ax];


#define LOGERR(fmt, ...) fprintf(stderr, "\nERROR: " fmt "\n\n", ## __VA_ARGS__)


int main (int argc, char *argv[])
{
	uint32_t words, count;
	uint16_t far *ptr;
	int mode = 1, fd;

	char *path = NULL;

	if (argc > 1)
		mode = atoi (argv[1]);

	bios_window = (volatile uint8_t far *) MK_FP(0xc000, 0x0000);

	ide_sector = (uint16_t far *) &bios_window[JRIDE_IDE_DATA_WIN];
	ide_window =  (uint8_t far *) &bios_window[JRIDE_IDE_REG_BASE];

	ide_window[IDE_REG_FEATURE] = mode;
	ide_window[IDE_REG_COMMAND] = IDE_CMD_PULL_REQUEST;

	while (ide_window[IDE_REG_STATUS] & 0x80); // busy

	if (ide_window[IDE_REG_STATUS] & 1) // error bit
	{
		LOGERR("Error pulling file\n");

		return -1;
	}

	count = words = (((uint32_t) ide_window[IDE_REG_ADDR_CYL_H]) << 16)
	              | (((uint32_t) ide_window[IDE_REG_ADDR_CYL_L]) << 8)
	              |  ((uint32_t) ide_window[IDE_REG_ADDR_SEC]);

	ptr = (uint16_t far *) MK_FP(get_ds(), sector);

	while (count)
	{
		while (!(ide_window[IDE_REG_STATUS] & 0x08));

		_xfer_sector_in (ptr);

		ptr += 256;

		if (count >= 256)
			count -= 256;
		else
			break;
	}

	if (mode == 0)
	{
		int i;

		volatile uint16_t far *dst = (volatile uint16_t far *) bios_window;

		for (i = 0; i < words; i++, dst++)
			*dst = sector[i];

		printf ("Loaded %d bytes at 0xc0000\n", words << 1);

		return 0;
	}


	switch (mode)
	{
	default:
	case 1: path = "pimount.com"; break;
	case 2: path = "picon.com"; break;
	}

	unlink (path);
	fd = open (path, O_RDWR | O_CREAT | O_BINARY, 0644);
	write (fd, sector, words << 1);
	close (fd);

	printf ("wrote %u bytes to %s\n", (unsigned) (words << 1), path);

	return 0;
}