in efi/libstub/efi-stub.c [117:312]
efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
efi_system_table_t *sys_table_arg)
{
efi_loaded_image_t *image;
efi_status_t status;
unsigned long image_addr;
unsigned long image_size = 0;
/* addr/point and size pairs for memory management*/
unsigned long initrd_addr = 0;
unsigned long initrd_size = 0;
unsigned long fdt_addr = 0; /* Original DTB */
unsigned long fdt_size = 0;
char *cmdline_ptr = NULL;
int cmdline_size = 0;
efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
unsigned long reserve_addr = 0;
unsigned long reserve_size = 0;
enum efi_secureboot_mode secure_boot;
struct screen_info *si;
efi_properties_table_t *prop_tbl;
efi_system_table = sys_table_arg;
/* Check if we were booted by the EFI firmware */
if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
status = EFI_INVALID_PARAMETER;
goto fail;
}
status = check_platform_features();
if (status != EFI_SUCCESS)
goto fail;
/*
* Get a handle to the loaded image protocol. This is used to get
* information about the running image, such as size and the command
* line.
*/
status = efi_system_table->boottime->handle_protocol(handle,
&loaded_image_proto, (void *)&image);
if (status != EFI_SUCCESS) {
efi_err("Failed to get loaded image protocol\n");
goto fail;
}
/*
* Get the command line from EFI, using the LOADED_IMAGE
* protocol. We are going to copy the command line into the
* device tree, so this can be allocated anywhere.
*/
cmdline_ptr = efi_convert_cmdline(image, &cmdline_size);
if (!cmdline_ptr) {
efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
status = EFI_OUT_OF_RESOURCES;
goto fail;
}
if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
cmdline_size == 0) {
status = efi_parse_options(CONFIG_CMDLINE);
if (status != EFI_SUCCESS) {
efi_err("Failed to parse options\n");
goto fail_free_cmdline;
}
}
if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
status = efi_parse_options(cmdline_ptr);
if (status != EFI_SUCCESS) {
efi_err("Failed to parse options\n");
goto fail_free_cmdline;
}
}
efi_info("Booting Linux Kernel...\n");
si = setup_graphics();
status = handle_kernel_image(&image_addr, &image_size,
&reserve_addr,
&reserve_size,
image);
if (status != EFI_SUCCESS) {
efi_err("Failed to relocate kernel\n");
goto fail_free_screeninfo;
}
efi_retrieve_tpm2_eventlog();
/* Ask the firmware to clear memory on unclean shutdown */
efi_enable_reset_attack_mitigation();
secure_boot = efi_get_secureboot();
/*
* Unauthenticated device tree data is a security hazard, so ignore
* 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
* boot is enabled if we can't determine its state.
*/
if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
secure_boot != efi_secureboot_mode_disabled) {
if (strstr(cmdline_ptr, "dtb="))
efi_err("Ignoring DTB from command line.\n");
} else {
status = efi_load_dtb(image, &fdt_addr, &fdt_size);
if (status != EFI_SUCCESS) {
efi_err("Failed to load device tree!\n");
goto fail_free_image;
}
}
if (fdt_addr) {
efi_info("Using DTB from command line\n");
} else {
/* Look for a device tree configuration table entry. */
fdt_addr = (uintptr_t)get_fdt(&fdt_size);
if (fdt_addr)
efi_info("Using DTB from configuration table\n");
}
if (!fdt_addr)
efi_info("Generating empty DTB\n");
efi_load_initrd(image, &initrd_addr, &initrd_size, ULONG_MAX,
efi_get_max_initrd_addr(image_addr));
efi_random_get_seed();
/*
* If the NX PE data feature is enabled in the properties table, we
* should take care not to create a virtual mapping that changes the
* relative placement of runtime services code and data regions, as
* they may belong to the same PE/COFF executable image in memory.
* The easiest way to achieve that is to simply use a 1:1 mapping.
*/
prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
flat_va_mapping = prop_tbl &&
(prop_tbl->memory_protection_attribute &
EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
/* force efi_novamap if SetVirtualAddressMap() is unsupported */
efi_novamap |= !(get_supported_rt_services() &
EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP);
/* hibernation expects the runtime regions to stay in the same place */
if (!IS_ENABLED(CONFIG_HIBERNATION) && !efi_nokaslr && !flat_va_mapping) {
/*
* Randomize the base of the UEFI runtime services region.
* Preserve the 2 MB alignment of the region by taking a
* shift of 21 bit positions into account when scaling
* the headroom value using a 32-bit random value.
*/
static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
EFI_RT_VIRTUAL_BASE -
EFI_RT_VIRTUAL_SIZE;
u32 rnd;
status = efi_get_random_bytes(sizeof(rnd), (u8 *)&rnd);
if (status == EFI_SUCCESS) {
virtmap_base = EFI_RT_VIRTUAL_BASE +
(((headroom >> 21) * rnd) >> (32 - 21));
}
}
install_memreserve_table();
status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
initrd_addr, initrd_size,
cmdline_ptr, fdt_addr, fdt_size);
if (status != EFI_SUCCESS)
goto fail_free_initrd;
if (IS_ENABLED(CONFIG_ARM))
efi_handle_post_ebs_state();
efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
/* not reached */
fail_free_initrd:
efi_err("Failed to update FDT and exit boot services\n");
efi_free(initrd_size, initrd_addr);
efi_free(fdt_size, fdt_addr);
fail_free_image:
efi_free(image_size, image_addr);
efi_free(reserve_size, reserve_addr);
fail_free_screeninfo:
free_screen_info(si);
fail_free_cmdline:
efi_bs_call(free_pool, cmdline_ptr);
fail:
return status;
}