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author | Sebastian Schmelzer | 2010-10-25 16:53:54 +0200 |
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committer | Sebastian Schmelzer | 2010-10-25 16:53:54 +0200 |
commit | 3050a9253437f4a4b5ad4bf3b3efdc3c660a5137 (patch) | |
tree | 91ac22153e416aac7ca20916b314b5e2ffa871b1 /contrib/syslinux-4.02/com32/modules/ifplop.c | |
download | preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.tar.gz preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.tar.xz preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.zip |
Diffstat (limited to 'contrib/syslinux-4.02/com32/modules/ifplop.c')
-rw-r--r-- | contrib/syslinux-4.02/com32/modules/ifplop.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/modules/ifplop.c b/contrib/syslinux-4.02/com32/modules/ifplop.c new file mode 100644 index 0000000..a846df8 --- /dev/null +++ b/contrib/syslinux-4.02/com32/modules/ifplop.c @@ -0,0 +1,170 @@ +/* ----------------------------------------------------------------------- * + * + * 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; +} |