Archipelago » qemu

/*

 * Block driver for the various disk image formats used by Bochs

 * Currently only for "growing" type in read-only mode

 * Copyright (c) 2005 Alex Beregszaszi

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

    char subtype[16]; // "Undoable" / "Volatile" / "Growing"

    uint32_t version;

    uint32_t header; // size of header

    union {

	struct {

	    uint32_t catalog; // num of entries

    char subtype[16]; // "Undoable" / "Volatile" / "Growing"

    uint32_t version;

    uint32_t header; // size of header

    union {

	struct {

	    uint32_t catalog; // num of entries

    uint32_t *catalog_bitmap;

    int catalog_size;

    int data_offset;

    int bitmap_blocks;

    int extent_blocks;

    int extent_size;

static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)

{

    const struct bochs_header *bochs = (const void *)buf;

    if (buf_size < HEADER_SIZE)

	return 0;

        if (fd < 0)

            return -1;

    }

    bs->read_only = 1; // no write support yet

    s->fd = fd;

    if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) {

    s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;

    s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;

    s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);

    return 0;

    // seek to sector

    extent_index = offset / s->extent_size;

    extent_offset = (offset % s->extent_size) / 512;

    if (s->catalog_bitmap[extent_index] == 0xffffffff)

    {

//	fprintf(stderr, "page not allocated [%x - %x:%x]\n",

    bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *

	(s->extent_blocks + s->bitmap_blocks));

    block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));

//    fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n",

//	sector_num, extent_index, extent_offset,

//	le32_to_cpu(s->catalog_bitmap[extent_index]),

//	bitmap_offset, block_offset);

    // read in bitmap for current extent

    lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET);

    read(s->fd, &bitmap_entry, 1);

    if (!((bitmap_entry >> (extent_offset % 8)) & 1))

    {

//	fprintf(stderr, "sector (%x) in bitmap not allocated\n",

    }

    lseek(s->fd, block_offset, SEEK_SET);

    return 0;

}

                    uint8_t *buf, int nb_sectors)

{

    BDRVBochsState *s = bs->opaque;