Add VHD hard disc image support. Patch from shermanp.

src/minivhd/minivhd_convert.c

@@ -0,0 +1,105 @@
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include "minivhd_create.h"
+#include "minivhd_internal.h"
+#include "minivhd_util.h"
+#include "minivhd.h"
+
+static FILE* mvhd_open_existing_raw_img(const char* utf8_raw_path, MVHDGeom* geom, int* err);
+
+static FILE* mvhd_open_existing_raw_img(const char* utf8_raw_path, MVHDGeom* geom, int* err) {
+    FILE *raw_img = mvhd_fopen(utf8_raw_path, "rb", err);
+    if (raw_img == NULL) {
+        *err = MVHD_ERR_FILE;
+        return NULL;
+    }
+    if (geom == NULL) {
+        *err = MVHD_ERR_INVALID_GEOM;
+        return NULL;
+    }
+    mvhd_fseeko64(raw_img, 0, SEEK_END);
+    uint64_t size_bytes = (uint64_t)mvhd_ftello64(raw_img);
+    MVHDGeom new_geom = mvhd_calculate_geometry(size_bytes);
+    if (mvhd_calc_size_bytes(&new_geom) != size_bytes) {
+        *err = MVHD_ERR_CONV_SIZE;
+        return NULL;
+    }
+    geom->cyl = new_geom.cyl;
+    geom->heads = new_geom.heads;
+    geom->spt = new_geom.spt;
+    mvhd_fseeko64(raw_img, 0, SEEK_SET);
+    return raw_img;
+}
+
+MVHDMeta* mvhd_convert_to_vhd_fixed(const char* utf8_raw_path, const char* utf8_vhd_path, int* err) {
+    MVHDGeom geom;
+    FILE *raw_img = mvhd_open_existing_raw_img(utf8_raw_path, &geom, err);
+    if (raw_img == NULL) {
+        return NULL;
+    }    
+    uint64_t size_in_bytes = mvhd_calc_size_bytes(&geom);
+    MVHDMeta *vhdm = mvhd_create_fixed_raw(utf8_vhd_path, raw_img, size_in_bytes, &geom, err, NULL);
+    if (vhdm == NULL) {
+        return NULL;
+    }
+    return vhdm;
+}
+MVHDMeta* mvhd_convert_to_vhd_sparse(const char* utf8_raw_path, const char* utf8_vhd_path, int* err) {
+    MVHDGeom geom;
+    MVHDMeta *vhdm = NULL;
+    FILE *raw_img = mvhd_open_existing_raw_img(utf8_raw_path, &geom, err);
+    if (raw_img == NULL) {
+        return NULL;
+    }
+    vhdm = mvhd_create_sparse(utf8_vhd_path, geom, err);
+    if (vhdm == NULL) {
+        goto end;
+    }
+    uint8_t buff[4096] = {0}; // 8 sectors
+    uint8_t empty_buff[4096] = {0};
+    int total_sectors = mvhd_calc_size_sectors(&geom);
+    int copy_sect = 0;
+    for (int i = 0; i < total_sectors; i += 8) {
+        copy_sect = 8;
+        if ((i + 8) >= total_sectors) {
+            copy_sect = total_sectors - i;
+            memset(buff, 0, sizeof buff);
+        }
+        fread(buff, MVHD_SECTOR_SIZE, copy_sect, raw_img);
+        /* Only write data if there's data to write, to take advantage of the sparse VHD format */
+        if (memcmp(buff, empty_buff, sizeof buff) != 0) {
+            mvhd_write_sectors(vhdm, i, copy_sect, buff);
+        }
+    }
+end:
+    fclose(raw_img);
+    return vhdm;
+}
+FILE* mvhd_convert_to_raw(const char* utf8_vhd_path, const char* utf8_raw_path, int *err) {
+    FILE *raw_img = mvhd_fopen(utf8_raw_path, "wb", err);
+    if (raw_img == NULL) {
+        return NULL;
+    }
+    MVHDMeta *vhdm = mvhd_open(utf8_vhd_path, true, err);
+    if (vhdm == NULL) {
+        fclose(raw_img);
+        return NULL;
+    }
+    uint8_t buff[4096] = {0}; // 8 sectors
+    int total_sectors = mvhd_calc_size_sectors((MVHDGeom*)&vhdm->footer.geom);
+    int copy_sect = 0;
+    for (int i = 0; i < total_sectors; i += 8) {
+        copy_sect = 8;
+        if ((i + 8) >= total_sectors) {
+            copy_sect = total_sectors - i;
+        }
+        mvhd_read_sectors(vhdm, i, copy_sect, buff);
+        fwrite(buff, MVHD_SECTOR_SIZE, copy_sect, raw_img);
+    }
+    mvhd_close(vhdm);
+    mvhd_fseeko64(raw_img, 0, SEEK_SET);
+    return raw_img;
+}