// Driver entry point. Initializes globals and registers driver node in /dev.
kern_return_t pmem_start(kmod_info_t * ki, void *d) {
int error = 0;
pmem_log("Loading /dev/%s driver", pmem_pmem_devname);
// Memory allocations are tagged to prevent leaks
pmem_tag = OSMalloc_Tagalloc(pmem_tagname, OSMT_DEFAULT);
// Allocate one page for zero padding of illegal read requests
pmem_zero_page = static_cast<uint8_t *>(OSMalloc(PAGE_SIZE, pmem_tag));
if (pmem_zero_page == NULL) {
pmem_error("Failed to allocate memory for page buffer");
return pmem_cleanup(KERN_FAILURE);
}
bzero(pmem_zero_page, PAGE_SIZE);
// Access the boot arguments through the platform export,
// and parse the systems physical memory configuration.
boot_args * ba = reinterpret_cast<boot_args *>(PE_state.bootArgs);
pmem_physmem_size = ba->PhysicalMemorySize;
pmem_mmap = reinterpret_cast<EfiMemoryRange *>(ba->MemoryMap +
pmem_kernel_voffset);
pmem_mmap_desc_size = ba->MemoryMapDescriptorSize;
pmem_mmap_size = ba->MemoryMapSize;
pmem_log("Size of physical memory:%lld", pmem_physmem_size);
pmem_log("Size of physical pages:%d (PAGE_SHIFT=%d, PAGE_MASK=%#016x)",
PAGE_SIZE, PAGE_SHIFT, PAGE_MASK);
pmem_log("Phys. Memory map at:%#016llx (size:%lld desc_size:%d)",
pmem_mmap, pmem_mmap_size, pmem_mmap_desc_size);
pmem_log("Number of segments in memory map: %d",
pmem_mmap_size / pmem_mmap_desc_size);
// Install switch table
pmem_devmajor = cdevsw_add(-1, &pmem_cdevsw);
if (pmem_devmajor == -1) {
pmem_error("Failed to create character device");
return pmem_cleanup(KERN_FAILURE);
}
// Create physical memory device file
pmem_log("Adding node /dev/%s", pmem_pmem_devname);
pmem_devpmemnode = devfs_make_node(makedev(pmem_devmajor,
pmem_dev_pmem_minor),
DEVFS_CHAR,
UID_ROOT,
GID_WHEEL,
0660,
pmem_pmem_devname);
if (pmem_devpmemnode == NULL) {
pmem_error("Failed to create /dev/%s node", pmem_pmem_devname);
return pmem_cleanup(KERN_FAILURE);
}
pmem_log("obtaining kernel dtb pointer");
__asm__ __volatile__("movq %%cr3, %0" :"=r"(pmem_dtb));
// Only bits 51-12 (inclusive) in cr3 are part of the dtb pointer
pmem_dtb &= ~PAGE_MASK;
pmem_log("kernel dtb: %#016llx", pmem_dtb);
pmem_log("initializing pte_mmap module");
pmem_log("pmem driver loaded, physical memory available in /dev/%s",
pmem_pmem_devname);
return error;
}
// Driver entry point. Initializes globals and registers driver node in /dev.
kern_return_t chipsec_start(kmod_info_t * ki, void *d) {
int error = 0;
pmem_log("Loading /dev/%s driver", chipsec_devname);
// Memory allocations are tagged to prevent leaks
pmem_tag = OSMalloc_Tagalloc(pmem_tagname, OSMT_DEFAULT);
// Allocate one page for zero padding of illegal read requests
pmem_zero_page = static_cast<uint8_t *>(OSMalloc(PAGE_SIZE, pmem_tag));
if (pmem_zero_page == NULL) {
pmem_error("Failed to allocate memory for page buffer");
return pmem_cleanup(KERN_FAILURE);
}
bzero(pmem_zero_page, PAGE_SIZE);
// Install the character device
chipsec_dev_major = cdevsw_add(-1, &pmem_cdevsw);
if (chipsec_dev_major == -1) {
pmem_error("Failed to create character device");
return pmem_cleanup(KERN_FAILURE);
}
// Create physical memory device file
pmem_log("Adding node /dev/%s", chipsec_devname);
pmem_devpmemnode = devfs_make_node(makedev(chipsec_dev_major,
chipsec_dev_minor),
DEVFS_CHAR,
UID_ROOT,
GID_WHEEL,
0660,
chipsec_devname);
if (pmem_devpmemnode == NULL) {
pmem_error("Failed to create /dev/%s node", chipsec_devname);
return pmem_cleanup(KERN_FAILURE);
}
pmem_log("pmem driver loaded, physical memory available in /dev/%s",
chipsec_devname);
return error;
}
// Driver cleanup function, frees all memory and removes device nodes.
kern_return_t pmem_stop(kmod_info_t *ki, void *d) {
pmem_log("Unloading /dev/%s driver", pmem_pmem_devname);
return pmem_cleanup(KERN_SUCCESS);
}
