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-rw-r--r--contrib/syslinux-4.02/dosutil/mdiskchk.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/dosutil/mdiskchk.c b/contrib/syslinux-4.02/dosutil/mdiskchk.c
new file mode 100644
index 0000000..47bb08e
--- /dev/null
+++ b/contrib/syslinux-4.02/dosutil/mdiskchk.c
@@ -0,0 +1,357 @@
+/* -*- c -*- ------------------------------------------------------------- *
+ *
+ * Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
+ * Portions copyright 2010 Shao Miller
+ *
+ * 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 <ctype.h>
+#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;
+
+/* Pull in MEMDISK common structures */
+#include "../memdisk/mstructs.h"
+
+struct memdiskinfo {
+ struct mdi mdi;
+
+ /* 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, 454d0800h;
+ mov ecx, 444d0000h;
+ mov edx, 53490000h;
+ mov dl, _dl;
+ mov ebx, 3f4b0000h;
+ int 13h;
+ 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;
+ }
+}
+
+/* The function type for an output function */
+#define OUTPUT_FUNC_DECL(x) \
+void x(const int d, const struct memdiskinfo * const m)
+typedef OUTPUT_FUNC_DECL((*output_func));
+
+/* Show MEMDISK information for the passed structure */
+static OUTPUT_FUNC_DECL(normal_output)
+{
+ if (m == NULL)
+ return;
+ 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->mdi.version_major, m->mdi.version_minor,
+ m->mdi.diskbuf, m->mdi.disksize, m->cylinders, m->heads, m->sectors,
+ m->mdi.bootloaderid, bootloadername(m->mdi.bootloaderid),
+ MK_FP(m->mdi.cmdline.seg_off.segment,
+ m->mdi.cmdline.seg_off.offset));
+}
+
+/* Yield DOS SET command(s) as output for each MEMDISK kernel argument */
+static OUTPUT_FUNC_DECL(batch_output)
+{
+ if (m != NULL) {
+ char buf[256], *bc;
+ const char far *c =
+ MK_FP(m->mdi.cmdline.seg_off.segment,
+ m->mdi.cmdline.seg_off.offset);
+ const char *have_equals, is_set[] = "=1";
+
+ while (*c != '\0') {
+ /* Skip whitespace */
+ while (isspace(*c))
+ c++;
+ if (*c == '\0')
+ /* Trailing whitespace. That's enough processing */
+ break;
+ /* Walk the kernel arguments while filling the buffer,
+ * looking for space or NUL or checking for a full buffer
+ */
+ bc = buf;
+ have_equals = is_set;
+ while ((*c != '\0') && !isspace(*c) &&
+ (bc < &buf[sizeof(buf) - 1])) {
+ /* Check if the param is "x=y" */
+ if (*c == '=')
+ /* "=1" not needed */
+ have_equals = &is_set[sizeof(is_set) - 1];
+ *bc = *c;
+ c++;
+ bc++;
+ }
+ /* Found the end of the parameter and optional value sequence */
+ *bc = '\0';
+ printf("set %s%s\n", buf, have_equals);
+ }
+ }
+}
+
+/* We do not output batch file output by default. We show MEMDISK info */
+static output_func show_memdisk = normal_output;
+
+/* A generic function type */
+#define MDISKCHK_FUNC_DECL(x) \
+void x(void)
+typedef MDISKCHK_FUNC_DECL((*mdiskchk_func));
+
+static MDISKCHK_FUNC_DECL(do_nothing)
+{
+ return;
+}
+
+static MDISKCHK_FUNC_DECL(show_usage)
+{
+ printf("\nUsage: mdiskchk [--safe-hooks] [--mbfts] [--batch-output]\n"
+ "\n"
+ "Action: --safe-hooks . . Will scan INT 13h \"safe hook\" chain\n"
+ " --mbfts . . . . Will scan memory for MEMDISK mBFTs\n"
+ " --batch-output . Will output SET command output based\n"
+ " on MEMDISK kernel arguments\n"
+ " --no-sequential Suppresses probing all drive numbers\n");
+}
+
+/* Search memory for mBFTs and report them via the output method */
+static MDISKCHK_FUNC_DECL(show_mbfts)
+{
+ const uint16_t far * const free_base_mem =
+ MK_FP(0x0040, 0x0013);
+ int seg;
+ uint8_t chksum;
+ uint32_t i;
+ const struct mBFT far *mbft;
+ struct memdiskinfo m;
+ struct patch_area far *patch_area;
+
+ for (seg = *free_base_mem / 16; seg < 0x9FFF; seg++) {
+ mbft = MK_FP(seg, 0);
+ /* Check for signature */
+ if (mbft->acpi.signature[0] != 'm' ||
+ mbft->acpi.signature[1] != 'B' ||
+ mbft->acpi.signature[2] != 'F' ||
+ mbft->acpi.signature[3] != 'T')
+ continue;
+ if (mbft->acpi.length != sizeof(struct mBFT))
+ continue;
+ /* Check sum */
+ chksum = 0;
+ for (i = 0; i < sizeof(struct mBFT); i++)
+ chksum += ((const uint8_t far *)mbft)[i];
+ if (chksum)
+ continue;
+ /* Copy the MDI from the mBFT */
+ _fmemcpy((void far *)&m, &mbft->mdi, sizeof(struct mdi));
+ /* Adjust C/H/S since we actually know
+ * it directly for any MEMDISK with an mBFT
+ */
+ patch_area = (struct patch_area far *)&mbft->mdi;
+ m.cylinders = patch_area->cylinders;
+ m.heads = patch_area->heads;
+ m.sectors = patch_area->sectors;
+ show_memdisk(patch_area->driveno, &m);
+ }
+}
+
+/* Walk the "safe hook" chain as far as possible
+ * and report MEMDISKs that we find via the output method
+ */
+static MDISKCHK_FUNC_DECL(show_safe_hooks)
+{
+ const real_addr_t far * const int13 =
+ MK_FP(0x0000, 0x0013 * sizeof(real_addr_t));
+ const struct safe_hook far *hook =
+ MK_FP(int13->seg_off.segment, int13->seg_off.offset);
+
+ while ((hook->signature[0] == '$') &&
+ (hook->signature[1] == 'I') &&
+ (hook->signature[2] == 'N') &&
+ (hook->signature[3] == 'T') &&
+ (hook->signature[4] == '1') &&
+ (hook->signature[5] == '3') &&
+ (hook->signature[6] == 'S') &&
+ (hook->signature[7] == 'F')) {
+ /* Found a valid "safe hook" */
+ if ((hook->vendor[0] == 'M') &&
+ (hook->vendor[1] == 'E') &&
+ (hook->vendor[2] == 'M') &&
+ (hook->vendor[3] == 'D') &&
+ (hook->vendor[4] == 'I') &&
+ (hook->vendor[5] == 'S') &&
+ (hook->vendor[6] == 'K')) {
+ /* Found a valid MEMDISK "safe hook". It will have an mBFT */
+ const struct mBFT far *mbft;
+ struct memdiskinfo m;
+ struct patch_area far *patch_area;
+
+ /* Copy the MDI from the mBFT. Offset is a misnomer here */
+ mbft = MK_FP(hook->mbft >> 4, 0); /* Always aligned */
+ _fmemcpy((void far *)&m, &mbft->mdi, sizeof(struct mdi));
+ /* Adjust C/H/S since we actually know
+ * it directly for any MEMDISK with an mBFT
+ */
+ patch_area = (struct patch_area far *)&mbft->mdi;
+ m.cylinders = patch_area->cylinders;
+ m.heads = patch_area->heads;
+ m.sectors = patch_area->sectors;
+ show_memdisk(patch_area->driveno, &m);
+ } /* if */
+ /* Step to the next hook in the "safe hook" chain */
+ hook = MK_FP(hook->old_hook.seg_off.segment,
+ hook->old_hook.seg_off.offset);
+ } /* while */
+}
+
+int main(int argc, char *argv[])
+{
+ int d;
+ int found = 0;
+ int sequential_scan = 1; /* Classic behaviour */
+ const struct memdiskinfo *m;
+
+ /* Default behaviour */
+ mdiskchk_func usage = do_nothing,
+ safe_hooks = do_nothing,
+ mbfts = do_nothing;
+
+ /* For each argument */
+ while (--argc) {
+ /* Argument should begin with one of these chars */
+ if ((*argv[argc] != '/') && (*argv[argc] != '-')) {
+ /* It doesn't. Print usage soon */
+ usage = show_usage;
+ break;
+ }
+ argv[argc]++;
+
+ /* Next char might be '-' as in "--safe-hooks" */
+ if (*argv[argc] == '-')
+ argv[argc]++;
+
+ switch (*argv[argc]) {
+ case 'S':
+ case 's':
+ safe_hooks = show_safe_hooks;
+ break;
+ case 'M':
+ case 'm':
+ mbfts = show_mbfts;
+ break;
+ case 'B':
+ case 'b':
+ show_memdisk = batch_output;
+ break;
+ case 'N':
+ case 'n':
+ sequential_scan = 0;
+ break;
+ default:
+ usage = show_usage;
+ } /* switch */
+ } /* while */
+
+ safe_hooks();
+ mbfts();
+ if (!sequential_scan)
+ goto skip_sequential;
+ for (d = 0; d <= 0xff; d++) {
+ m = query_memdisk(d);
+ if (m != NULL) {
+ found++;
+ show_memdisk(d, m);
+ }
+ }
+skip_sequential:
+ usage();
+
+ return found;
+}
+
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