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/* ----------------------------------------------------------------------- *
*
* Copyright 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., 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.
*
* ----------------------------------------------------------------------- */
/*
* gpxecmd.c
*
* Invoke an arbitrary gPXE command, if available.
*/
#include <alloca.h>
#include <inttypes.h>
#include <stdio.h>
#include <console.h>
#include <com32.h>
#include <stdbool.h>
#include <string.h>
#include <syslinux/config.h>
struct segoff16 {
uint16_t offs, seg;
};
struct s_PXENV_FILE_CHECK_API {
uint16_t Status;
uint16_t Size;
uint32_t Magic;
uint32_t Provider;
uint32_t APIMask;
uint32_t Flags;
};
static bool is_gpxe(void)
{
const struct syslinux_version *sv;
com32sys_t reg;
struct s_PXENV_FILE_CHECK_API *fca;
sv = syslinux_version();
if (sv->filesystem != SYSLINUX_FS_PXELINUX)
return false; /* Not PXELINUX */
fca = __com32.cs_bounce;
memset(fca, 0, sizeof *fca);
fca->Size = sizeof *fca;
fca->Magic = 0x91d447b2;
memset(®, 0, sizeof reg);
reg.eax.w[0] = 0x0009;
reg.ebx.w[0] = 0x00e6; /* PXENV_FILE_API_CHECK */
reg.edi.w[0] = OFFS(fca);
reg.es = SEG(fca);
__intcall(0x22, ®, ®);
if (reg.eflags.l & EFLAGS_CF)
return false; /* Cannot invoke PXE stack */
if (reg.eax.w[0] || fca->Status)
return false; /* PXE failure */
if (fca->Magic != 0xe9c17b20)
return false; /* Incorrect magic */
if (fca->Size < sizeof *fca)
return false; /* Short return */
if (!(fca->APIMask & (1 << 5)))
return false; /* No FILE EXEC */
return true;
}
struct s_PXENV_FILE_EXEC {
uint16_t Status;
struct segoff16 Command;
};
static void gpxecmd(const char **args)
{
char *q;
struct s_PXENV_FILE_EXEC *fx;
com32sys_t reg;
memset(®, 0, sizeof reg);
fx = __com32.cs_bounce;
q = (char *)(fx + 1);
fx->Status = 1;
fx->Command.offs = OFFS(q);
fx->Command.seg = SEG(q);
while (*args) {
q = stpcpy(q, *args);
*q++ = ' ';
args++;
}
*--q = '\0';
memset(®, 0, sizeof reg);
reg.eax.w[0] = 0x0009;
reg.ebx.w[0] = 0x00e5; /* PXENV_FILE_EXEC */
reg.edi.w[0] = OFFS(fx);
reg.es = SEG(fx);
__intcall(0x22, ®, ®);
/* This should not return... */
}
int main(int argc, const char *argv[])
{
openconsole(&dev_null_r, &dev_stdcon_w);
if (argc < 2) {
printf("Usage: gpxecmd command...\n");
return 1;
}
if (!is_gpxe()) {
printf("gpxecmd: gPXE API not detected\n");
return 1;
}
gpxecmd(argv + 1);
return 0;
}
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