From ff6d78bb1373700d3ca4563efccb47db58a94ccd Mon Sep 17 00:00:00 2001
From: shermp <14854761+shermp@users.noreply.github.com>
Date: Thu, 15 Nov 2018 14:02:38 +1300
Subject: [PATCH] Remove PCem specific limits

---
 minivhd.c | 7 +++----
 minivhd.h | 8 +++++---
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/minivhd.c b/minivhd.c
index f209fd5..4ba6472 100644
--- a/minivhd.c
+++ b/minivhd.c
@@ -329,13 +329,12 @@ VHDGeom vhd_calc_chs(uint32_t sz_mb)
         VHDGeom chs;
         uint32_t ts = ((uint64_t)sz_mb * 1024 * 1024) / VHD_SECTOR_SZ;
         uint32_t spt, heads, cyl, cth;
-        /* PCem does not currently support spt > 63 */
-        // if (ts > 65535 * 16 * 255)
-        //         ts = 65535 * 16 * 255;
+        if (ts > 65535 * 16 * 255)
+                ts = 65535 * 16 * 255;
         if (ts >= 65535 * 16 * 63)
         {
                 ts = 65535 * 16 * 63;
-                spt = 63;
+                spt = 255;
                 heads = 16;
                 cth = ts / spt;
         }
diff --git a/minivhd.h b/minivhd.h
index 90e3a50..fc333de 100644
--- a/minivhd.h
+++ b/minivhd.h
@@ -49,10 +49,12 @@
 #define VHD_SPARSE_BLK 0xffffffff
 #define VHD_DEF_BLOCK_SZ 2097152
 #define VHD_START_TS 946684800
-// #define MAX_BAT_SIZE_BYTES 16896
-#define VHD_MAX_BAT_SIZE_BYTES 64512 /* Enough entries for largest VHD PCem can create */
+
+/* Enough entries for largest VHD MiniVHD can create.
+   Calculated by ceil(65535 * 16 * 255 / 4096) * 4 */
+#define VHD_MAX_BAT_SIZE_BYTES 261120
 #define VHD_MAX_CYL 65535 /* VHD stores the cylinders as a 16-bit unsigned int */
-#define VHD_MAX_SZ_MB 32255 /* Using max (65535 * 16 * 63) geom  */
+#define VHD_MAX_SZ_MB 130559 /* Using max (65535 * 16 * 255) geom  */
 /* Win 10 appears to add 7 sectors of zero padding between blocks, and before the footer. */
 #define VHD_BLK_PADDING 3584