/* ----------------------------------------------------------------------- *
*
* 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>]
* Examples: ifplop.c32 menu.c32 another.cfg -- plpbt hiddenusb usb1=2
* You need to remove the ".bin" extension of the plpbt.bin file
* if you use it this way.
* ifplop.c32 plop_detected -- plop_not_detected
*
* 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
* # When using "LINUX plpbt.bin", you don't need to remove the .bin extension.
* LABEL plop_not_detected
* LINUX plpbt.bin
* APPEND 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 access the first 128GiB (137GB) on USB drives, while
* internal hard drives don't necessarily 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 whatever 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 hiddenusb usb1=2\n");
}
return 0;
}
