/*
 *	似非DOSフォーマット（試作品)
 *	(c)ささのたかよし	23-Aug-2000
 */

#include	<basic.h>
#include	<bstdio.h>
#include	<bstdlib.h>
#include	<bstring.h>
#include	<errcode.h>
#include	<btron/btron.h>
#include	<device/disk.h>

#define	MakerID		0x03
#define	SectorSize	0x0b
#define	ClusterSize	0x0d
#define	FATTop		0x0e
#define	FATs		0x10
#define	DirEntry	0x11
#define	TotalSector	0x13
#define	MediaID		0x15
#define	FATSize		0x16
#define	TrackSize	0x18
#define	Sides		0x1a
#define	HiddenSector	0x1c
#define	VolumeID	0x27

#define	DirEntrySize	0x20
#define	SECTORSIZE	0x200


/* boot sectorのデータ */

LOCAL	UB	boot_2dd[] = {
    0xeb, 0xfe,		/* JMP short 0000 (x86)				*/
    0x90,		/* NOP						*/
    'u', 'n', 'k', 'n', 'o', 'w', 'n', ' ',	/* vendor string	*/
    0x00, 0x02,		/* size of sector (0x0200 = 512 bytes)		*/
    0x02,		/* size of cluster (unit: sector)		*/
    0x01, 0x00,		/* top sector of FAT (reserved sector)		*/
    0x02,		/* number of FATs				*/
    0x70, 0x00,		/* number of directory entries (0x0070 = 112)	*/
    0xa0, 0x05,		/* sectors in disk (0x05a0 = 1440)		*/
    0xf9,		/* media ID (0xf9 = 2DD)			*/
    0x03, 0x00,		/* size of FAT (unit: sector)			*/
    0x09, 0x00,		/* sectors/track (0x0009 = 9 sectors/track)	*/
    0x02, 0x00,		/* sides (2 sides)				*/
    0x00, 0x00,		/* hidden sectors (none)			*/
    0x18, 0xfe,		/* JR 001e (Z80) (for MSX-DOS1 boot entry)	*/
    0x56, 0x4f, 0x4c, 0x5f, 0x49, 0x44, /* "VOL_ID" string (MSX-DOS2)	*/
    0x00,		/* undelete flag (for MSX-DOS2)			*/
    0x00, 0x00, 0x00, 0x00, 		/* volume ID			*/
    0x00, 0x00, 0x00, 0x00, 0x00,	/* reserved for future use	*/
    0x18, 0xfe		/* JR 0030 (Z80) (for MSX-DOS2 boot entry)	*/
};

LOCAL	UB	boot_2hd[] = {
    0xeb, 0xfe,		/* JMP short 0000 (x86)				*/
    0x90,		/* NOP (x86)					*/
    'u', 'n', 'k', 'n', 'o', 'w', 'n', ' ',	/* vendor string	*/
    0x00, 0x02,		/* size of sector (0x0200 = 512 bytes)		*/
    0x01,		/* size of cluster (unit: sector)		*/
    0x01, 0x00,		/* top sector of FAT (reserved sector)		*/
    0x02,		/* number of FATs				*/
    0xe0, 0x00,		/* number of directory entries (0x00e0 = 224)	*/
    0x40, 0x0b,		/* sectors in disk (0x0b40 = 2880)		*/
    0xf0,		/* media ID (0xf9 = 2HD)			*/
    0x09, 0x00,		/* size of FAT (unit: sector)			*/
    0x12, 0x00,		/* sectors/track (0x0012 = 18 sectors/track)	*/
    0x02, 0x00,		/* sides (2 sides)				*/
    0x00, 0x00,		/* hidden sectors (none)			*/
    0x18, 0xfe,		/* JR 001e (Z80) (for MSX-DOS1 boot entry)	*/
    0x56, 0x4f, 0x4c, 0x5f, 0x49, 0x44, /* "VOL_ID" string (MSX-DOS2)	*/
    0x00,		/* undelete flag (for MSX-DOS2)			*/
    0x00, 0x00, 0x00, 0x00, 		/* volume ID			*/
    0x00, 0x00, 0x00, 0x00, 0x00,	/* reserved for future use	*/
    0x18, 0xfe		/* JR 0030 (Z80) (for MSX-DOS2 boot entry)	*/
};



UB	*create_fat(UB *bootsect, const W bootsectsize, W *size)
{
    W	sectorsize, fat_start, fat_size, fats, dir_entry, dir_size, media_id;
    W	totalsector, totalmemory, i, pos;
    UB	*buf;

    /*	必要なパラメータのセット */
    sectorsize  = bootsect[SectorSize] + (bootsect[SectorSize + 1] << 8);
    fat_start   = bootsect[FATTop]     + (bootsect[FATTop + 1]     << 8);
    fat_size    = bootsect[FATSize]    + (bootsect[FATSize + 1]    << 8);
    fats        = bootsect[FATs];
    dir_entry   = bootsect[DirEntry]   + (bootsect[DirEntry + 1]   << 8);
    dir_size    = DirEntrySize * dir_entry / sectorsize;
    media_id    = bootsect[MediaID];
    totalsector = fat_start + fats * fat_size + dir_size;
    totalmemory = totalsector * sectorsize;

    /*
    printf("sectorsize : %d\n", sectorsize);
    printf("fat_start  : %d\n", fat_start);
    printf("fat_size   : %d\n", fat_size);
    printf("fats       : %d\n", fats);
    printf("dir_entry  : %d\n", dir_entry);
    printf("dir_size   : %d\n", dir_size);
    printf("totalsector: %d\n", totalsector);
    printf("totalmemory: %d\n", totalmemory);
    */

    /* メモリの確保 */
    if((buf = malloc(totalmemory)) == NULL) {
	printf("memory allocation error\n");
	goto	fin;
    }

    /* 0クリア */
    memset(buf, 0, totalmemory);

    /* boot sectorのコピー */
    memcpy(buf, bootsect, bootsectsize);

    /* FATの作成 */
    for(i = 0; i < fats; i++) {
	pos = (fat_start + fat_size * i) * sectorsize;
	buf[pos]     = media_id;
	buf[pos + 1] = buf[pos + 2] = 0xff;
    }

    /* サイズを通知 */
    *size = totalmemory;

 fin:
    return buf;
}



WERR	main(W argc, TC *argv[])
{
    W		dd, imgsize, rsz;
    UB		*buf;
    TC		fda[] = {L"ｆｄａ"}, fdb[] = {L"ｆｄｂ"}, *target_drive;
    WERR	err;
    DiskInfo	di;

    /* 使い方を表示 */
    if(argc < 2) {
	printf("usage: mkfat [a|b]\n");
	err = EC_PAR;
	goto	fin0;
    }

    /* ドライブ名の指定 */
    switch(*argv[1]) {
    case	L'ａ':
	target_drive = fda;
	break;

    case	L'ｂ':
	target_drive = fdb;
	break;

    default:
	printf("bad option\n");
	err = EC_PAR;
	goto	fin0;
    }

    /* デバイスをオープン */
    if((err = opn_dev(target_drive, D_UPDATE | D_EXCL, NULL)) < EC_OK) {
	printf("opn_dev(): failed (%d)\n", err);
	goto	fin0;
    }
    dd = err;

    /* ディスクのチェック */
    if((err = rea_dev(dd, DN_DISKINFO, (UB *)&di, sizeof(di), &rsz, NULL))
       < EC_OK) {
	printf("rea_dev(): failed (%d)\n", err);
	goto	fin1;
    }

    /* 書き込み禁止か？ */
    if(di.protect) {
	printf("Write protected\n");
	err = EC_RONLY;
	goto	fin1;
    }

    /* セクタサイズは512バイトか？ */
    if(di.blocksize != SECTORSIZE) {
	printf("Bad sector size (%d)\n", di.blocksize);
	err = EC_NOSPT;
	goto	fin1;
    }

    /* ディスクに合わせてイメージを作成 */
    switch(di.format) {
    case	DiskFmt_2DD:
	printf("2DD disk found\n");
	buf = create_fat(boot_2dd, sizeof(boot_2dd), &imgsize);
	break;
    case	DiskFmt_2HD:
	printf("2HD disk found\n");
	buf = create_fat(boot_2hd, sizeof(boot_2hd), &imgsize);
	break;
    default:
	printf("not supported media found(%d)\n", di.format);
	err = EC_NOSPT;
	goto	fin1;
    }

    /* イメージの作成に失敗したら中断 */
    if(buf == NULL) {
	printf("create_fat(): failed\n");
	goto	fin1;
    }

    /* さあ書き込んでみよう */
    if((err = wri_dev(dd, 0, buf, imgsize / SECTORSIZE, &rsz, NULL)) < EC_OK) {
	printf("wri_dev(): failed (%d)\n", err);
	goto	fin2;
    }

    printf("imagesize: %d\n", imgsize);

    if(rsz != imgsize / SECTORSIZE) {
	printf("write image not completed\n");
	err = EC_IO;
	goto	fin2;
    }

    err = EC_OK;
 fin2:
    free(buf);
 fin1:
    cls_dev(dd, 1, NULL);
 fin0:
    return err;
}