[syslinux:master] ifplop.c32: Detect if PLoP USB/CD INT13h hook is enabled/disabled
syslinux-bot for Gert Hulselmans
gerth at zytor.com
Thu Jul 1 13:42:25 PDT 2010
Commit-ID: 01dc2ad8336cc9dbd76f1e74cd4fec2e45334797
Gitweb: http://syslinux.zytor.com/commit/01dc2ad8336cc9dbd76f1e74cd4fec2e45334797
Author: Gert Hulselmans <gerth at zytor.com>
AuthorDate: Thu, 1 Jul 2010 17:57:44 +0200
Committer: H. Peter Anvin <hpa at linux.intel.com>
CommitDate: Thu, 1 Jul 2010 13:39:34 -0700
ifplop.c32: Detect if PLoP USB/CD INT13h hook is enabled/disabled
New module which detects if the PLoP Boot Loader already has booted a
CDROM or USB drive by checking for the presence of the PLoP INT13h hook.
The following assembly code (NASM) can detect the PLoP INT13h hook:
mov eax,'PoLP' ; Reverse of 'PLoP'
mov ebp,'DKHC' ; Reverse of 'CHKD'
int 13h
cmp eax,' sey' ; Reverse of 'yes '
jz plop_INT13h_active
Signed-off-by: Gert Hulselmans <gerth at zytor.com>
Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
---
NEWS | 2 +
com32/modules/Makefile | 2 +-
com32/modules/ifplop.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 1 deletions(-)
diff --git a/NEWS b/NEWS
index 84b77c8..6fad010 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,8 @@ Changes in 4.01:
* ISOLINUX: change the initialization sequence to avoid
problems with certain (old) BIOSes. Special thanks to
Helmut Hullen for invaluable debugging support.
+ * ifplop.c32: new module which detects if the PLoP Boot Loader
+ already has booted a CDROM or USB drive (Gert Hulselmans).
Changes in 4.00:
* Major code base changes; all filesystem rewritten in C.
diff --git a/com32/modules/Makefile b/com32/modules/Makefile
index 79018df..f42ce96 100644
--- a/com32/modules/Makefile
+++ b/com32/modules/Makefile
@@ -22,7 +22,7 @@ MODULES = chain.c32 config.c32 ethersel.c32 dmitest.c32 cpuidtest.c32 \
disk.c32 pcitest.c32 elf.c32 linux.c32 reboot.c32 pmload.c32 \
meminfo.c32 sdi.c32 sanboot.c32 ifcpu64.c32 vesainfo.c32 \
kbdmap.c32 cmd.c32 vpdtest.c32 host.c32 ls.c32 gpxecmd.c32 \
- ifcpu.c32 cpuid.c32 cat.c32 pwd.c32
+ ifcpu.c32 cpuid.c32 cat.c32 pwd.c32 ifplop.c32
TESTFILES =
diff --git a/com32/modules/ifplop.c b/com32/modules/ifplop.c
new file mode 100644
index 0000000..c6286d9
--- /dev/null
+++ b/com32/modules/ifplop.c
@@ -0,0 +1,165 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2010 Gert Hulselmans - 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., 51 Franklin St, Fifth Floor,
+ * Boston MA 02110-1301, USA; either version 2 of the License, or
+ * (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * ifplop.c
+ *
+ * This COM32 module detects if the PLoP Boot Manager was used to boot a CDROM
+ * drive or USB drive, by checking for the presence of the PLoP INT13h hook.
+ *
+ * Usage: ifplop.c32 [<plop_detected>] -- [<plop_not_detected>]
+ * Example: ifplop.c32 menu.c32 another.cfg -- plpbt.bin hiddenusb usb1=2
+ *
+ * A possible config file could be:
+ *
+ * ===========================================================================
+ * DEFAULT plopcheck
+ *
+ * # Check for the presence of PLoP (run by default)
+ * # When PLoP INT13h hook is found, run the first command (plop_detected)
+ * # When PLoP INT13h hook isn't found, run the second command (plop_not_detected)
+ * LABEL plopcheck
+ * COM32 ifplop.c32
+ * APPEND plop_detected -- plop_not_detected
+ *
+ * # When PLoP INT13h hook was found, boot the menu system.
+ * # PLoP can have added USB 2.0 speed, so the entries we want to boot
+ * # will be read from disk much faster (supposing that we have a BIOS
+ * # that only supports USB 1.1 speed, but a mobo with USB 2.0 controllers).
+ * LABEL plop_detected
+ * COM32 menu.c32
+ * APPEND another.cfg
+ *
+ * # PLoP INT13h hook wasn't found, so we boot PLoP, so it can add USB 2.0 support
+ * LABEL plop_not_detected
+ * LINUX plpbt.bin hiddenusb usb1=2
+ *
+ * ===========================================================================
+ *
+ * Why is/can this module be useful?
+ *
+ * You may want to boot PLoP by default from Syslinux when you boot from your
+ * USB stick/drive:
+ * 1. PLoP can upgrade USB 1.1 speed offered by the BIOS to USB 2.0 speed
+ * if you have USB 2.0 controllers on your mobo.
+ * 2. Some BIOSes only can acees the first 128GiB (137GB) on USB drives, while
+ * internal hard drives don't neseccarily suffer from this 128GiB problem.
+ * Using PLoPs USB capabilities, you can access the whole drive.
+ *
+ * When you select the "USB" entry in PLoP, it will boot your USB stick/drive
+ * again and it will boot PLoP again when you have set booting PLoP as DEFAULT
+ * boot option in your Syslinux configuration file.
+ *
+ * By using ifplop.c32 you can specify which action you want to do the second
+ * time your USB stick/drive is booted. So you can load another config file or
+ * boot a large hard disk image or whathever you want.
+ *
+ * PLoP Boot Manager website: http://www.plop.at/en/bootmanager.html
+ */
+
+#include <com32.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <alloca.h>
+#include <console.h>
+#include <syslinux/boot.h>
+
+static bool plop_INT13h_check(void)
+{
+ com32sys_t inregs, outregs;
+
+ /* Prepare the register set */
+ memset(&inregs, 0, sizeof inregs);
+
+ /*
+ * Check if PLoP already has booted a CDROM or USB drive by checking
+ * for the presence of the PLoP INT13h hook.
+ *
+ * The following assembly code (NASM) can detect the PLoP INT13h hook:
+ *
+ * mov eax,'PoLP' ; Reverse of 'PLoP'
+ * mov ebp,'DKHC' ; Reverse of 'CHKD'
+ * int 13h
+ * cmp eax,' sey' ; Reverse of 'yes '
+ * jz plop_INT13h_active
+ */
+
+ inregs.eax.l = 0x504c6f50; /* "PLoP" */
+ inregs.ebp.l = 0x43484b44; /* "CHKD" */
+
+ __intcall(0x13, &inregs, &outregs);
+
+ /* eax will contain "yes " if PLoP INT13h hook is available */
+ if (outregs.eax.l == 0x79657320)
+ return true;
+
+ return false;
+}
+
+/* XXX: this really should be librarized */
+static void boot_args(char **args)
+{
+ int len = 0, a = 0;
+ char **pp;
+ const char *p;
+ char c, *q, *str;
+
+ for (pp = args; *pp; pp++)
+ len += strlen(*pp) + 1;
+
+ q = str = alloca(len);
+ for (pp = args; *pp; pp++) {
+ p = *pp;
+ while ((c = *p++))
+ *q++ = c;
+ *q++ = ' ';
+ a = 1;
+ }
+ q -= a;
+ *q = '\0';
+
+ if (!str[0])
+ syslinux_run_default();
+ else
+ syslinux_run_command(str);
+}
+
+int main(int argc, char *argv[])
+{
+ char **args[2];
+ int arg = 0;
+
+ openconsole(&dev_null_r, &dev_stdcon_w);
+
+ if (argc)
+ arg++;
+ args[0] = &argv[arg];
+ args[1] = NULL;
+ while (arg < argc) {
+ if (!strcmp(argv[arg], "--")) {
+ argv[arg] = NULL;
+ args[1] = &argv[arg + 1];
+ break;
+ }
+ arg++;
+ }
+ if (args[1] != NULL) {
+ boot_args(plop_INT13h_check()? args[0] : args[1]);
+ } else {
+ fprintf(stderr,
+ "Usage: ifplop.c32 [<plop_detected>] -- [<plop_not_detected>]\n"
+ "Example: ifplop.c32 menu.c32 another.cfg -- plpbt.bin hiddenusb usb1=2\n");
+ }
+
+ return 0;
+}
More information about the Syslinux-commits
mailing list