Create a dosutil subdirectory and move mdiskchk there

DOS utilities aren't really "samples".  Create a dedicated "dosutil"
directory, and move mdiskchk there for now.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 146 insertions, 0 deletions

diff --git a/dosutil/mdiskchk.c b/dosutil/mdiskchk.c
new file mode 100644
index 00000000..eec5be40
--- /dev/null
+++ b/dosutil/mdiskchk.c
@@ -0,0 +1,146 @@
+/* -*- c -*- ------------------------------------------------------------- *
+ *
+ *   Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
+ *
+ *   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, Inc., 53 Temple Place Ste 330,
+ *   Boston MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * mdiskchk.c
+ *
+ * DOS program to check for the existence of a memdisk.
+ *
+ * This program can be compiled for DOS with the OpenWatcom compiler
+ * (http://www.openwatcom.org/):
+ *
+ * wcl -3 -osx -mt mdiskchk.c
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <i86.h>		/* For MK_FP() */
+
+typedef unsigned long uint32_t;
+typedef unsigned short uint16_t;
+typedef unsigned char uint8_t;
+
+struct memdiskinfo {
+    uint16_t bytes;		/* Bytes from memdisk */
+    uint16_t version;		/* Memdisk version */
+    uint32_t base;		/* Base of disk in high memory */
+    uint32_t size;		/* Size of disk in sectors */
+    char far *cmdline;		/* Command line */
+    void far *oldint13;		/* Old INT 13h */
+    void far *oldint15;		/* Old INT 15h */
+    uint16_t olddosmem;
+    uint8_t bootloaderid;
+
+    uint8_t _pad;
+
+    /* We add our own fields at the end */
+    int cylinders;
+    int heads;
+    int sectors;
+};
+
+struct memdiskinfo *query_memdisk(int drive)
+{
+    static struct memdiskinfo mm;
+    uint32_t _eax, _ebx, _ecx, _edx;
+    uint16_t _es, _di;
+    unsigned char _dl = drive;
+    uint16_t bytes;
+
+    __asm {
+	.386;
+	mov eax, 454 d0800h;
+	mov ecx, 444 d0000h;
+	mov edx, 53490000 h;
+	mov dl, _dl;
+	mov ebx, 3f 4 b0000h;
+	int 13 h;
+	mov _eax, eax;
+	mov _ecx, ecx;
+	mov _edx, edx;
+	mov _ebx, ebx;
+	mov _es, es;
+	mov _di, di;
+    }
+
+    if (_eax >> 16 != 0x4d21 ||
+	_ecx >> 16 != 0x4d45 || _edx >> 16 != 0x4944 || _ebx >> 16 != 0x4b53)
+	return NULL;
+
+    memset(&mm, 0, sizeof mm);
+
+    bytes = *(uint16_t far *) MK_FP(_es, _di);
+
+    /* 27 is the most we know how to handle */
+    if (bytes > 27)
+	bytes = 27;
+
+    _fmemcpy((void far *)&mm, (void far *)MK_FP(_es, _di), bytes);
+
+    mm.cylinders = ((_ecx >> 8) & 0xff) + ((_ecx & 0xc0) << 2) + 1;
+    mm.heads = ((_edx >> 8) & 0xff) + 1;
+    mm.sectors = (_ecx & 0x3f);
+
+    return &mm;
+}
+
+const char *bootloadername(uint8_t id)
+{
+    static const struct {
+	uint8_t id, mask;
+	const char *name;
+    } *lp, list[] = {
+	{
+	0x00, 0xf0, "LILO"}, {
+	0x10, 0xf0, "LOADLIN"}, {
+	0x31, 0xff, "SYSLINUX"}, {
+	0x32, 0xff, "PXELINUX"}, {
+	0x33, 0xff, "ISOLINUX"}, {
+	0x34, 0xff, "EXTLINUX"}, {
+	0x30, 0xf0, "SYSLINUX family"}, {
+	0x40, 0xf0, "Etherboot"}, {
+	0x50, 0xf0, "ELILO"}, {
+	0x70, 0xf0, "GrUB"}, {
+	0x80, 0xf0, "U-Boot"}, {
+	0xA0, 0xf0, "Gujin"}, {
+	0xB0, 0xf0, "Qemu"}, {
+	0x00, 0x00, "unknown"}
+    };
+
+    for (lp = list;; lp++) {
+	if (((id ^ lp->id) & lp->mask) == 0)
+	    return lp->name;
+    }
+}
+
+int main(int argc, char *argv[])
+{
+    int d;
+    int found = 0;
+    struct memdiskinfo *m;
+
+    for (d = 0; d <= 0xff; d++) {
+	if ((m = query_memdisk(d)) != NULL) {
+	    printf("Drive %02X is MEMDISK %u.%02u:\n"
+		   "\tAddress = 0x%08lx, len = %lu sectors, chs = %u/%u/%u,\n"
+		   "\tloader = 0x%02x (%s),\n"
+		   "\tcmdline = %Fs\n",
+		   d, m->version >> 8, m->version & 0xff,
+		   m->base, m->size, m->cylinders, m->heads, m->sectors,
+		   m->bootloaderid, bootloadername(m->bootloaderid),
+		   m->cmdline);
+	    found++;
+	}
+    }
+
+    return found;
+}
diff --git a/dosutil/mdiskchk.com b/dosutil/mdiskchk.com
new file mode 100755
index 00000000..07e1471b
--- /dev/null
+++ b/dosutil/mdiskchk.com