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#include <sys/gpxe.h>
#include <syslinux/config.h>
#include <string.h>
bool is_gpxe(void)
{
const struct syslinux_version *sv;
com32sys_t reg;
struct s_PXENV_FILE_CHECK_API *fca;
bool gpxe;
sv = syslinux_version();
if (sv->filesystem != SYSLINUX_FS_PXELINUX)
return false; /* Not PXELINUX */
fca = lzalloc(sizeof *fca);
if (!fca)
return false;
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, ®, ®);
gpxe = true;
if (reg.eflags.l & EFLAGS_CF)
gpxe = false; /* Cannot invoke PXE stack */
if (reg.eax.w[0] || fca->Status)
gpxe = false; /* PXE failure */
if (fca->Magic != 0xe9c17b20)
gpxe = false; /* Incorrect magic */
if (fca->Size < sizeof *fca)
gpxe = false; /* Short return */
/* XXX: The APIs to test for should be a passed-in option */
if (!(fca->APIMask & (1 << 5)))
gpxe = false; /* No FILE EXEC */
lfree(fca);
return gpxe;
}
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