reserve_bios_regions
x86_platform.legacy.reserve_bios_regions = 0;
void reserve_bios_regions(void);
int reserve_bios_regions;
if (!x86_platform.legacy.reserve_bios_regions)
x86_platform.legacy.reserve_bios_regions = 0;
x86_platform.legacy.reserve_bios_regions = 1;
reserve_bios_regions();