/*
* EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
* that is described in the PE/COFF header. Most of the code is the same
* for both archictectures, with the arch-specific code provided in the
* handle_kernel_image() function.
*/
unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
unsigned long *image_addr)
{
efi_loaded_image_t *image;
efi_status_t status;
unsigned long image_size = 0;
unsigned long dram_base;
/* addr/point and size pairs for memory management*/
unsigned long initrd_addr;
u64 initrd_size = 0;
unsigned long fdt_addr = 0; /* Original DTB */
unsigned long fdt_size = 0;
char *cmdline_ptr = NULL;
int cmdline_size = 0;
unsigned long new_fdt_addr;
efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
unsigned long reserve_addr = 0;
unsigned long reserve_size = 0;
int secure_boot = 0;
struct screen_info *si;
/* Check if we were booted by the EFI firmware */
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
goto fail;
pr_efi(sys_table, "Booting Linux Kernel...\n");
status = check_platform_features(sys_table);
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 = sys_table->boottime->handle_protocol(handle,
&loaded_image_proto, (void *)&image);
if (status != EFI_SUCCESS) {
pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
goto fail;
}
dram_base = get_dram_base(sys_table);
if (dram_base == EFI_ERROR) {
pr_efi_err(sys_table, "Failed to find DRAM base\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(sys_table, image, &cmdline_size);
if (!cmdline_ptr) {
pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
goto fail;
}
/* check whether 'nokaslr' was passed on the command line */
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
static const u8 default_cmdline[] = CONFIG_CMDLINE;
const u8 *str, *cmdline = cmdline_ptr;
if (IS_ENABLED(CONFIG_CMDLINE_FORCE))
cmdline = default_cmdline;
str = strstr(cmdline, "nokaslr");
if (str == cmdline || (str > cmdline && *(str - 1) == ' '))
__nokaslr = true;
}
si = setup_graphics(sys_table);
status = handle_kernel_image(sys_table, image_addr, &image_size,
&reserve_addr,
&reserve_size,
dram_base, image);
if (status != EFI_SUCCESS) {
pr_efi_err(sys_table, "Failed to relocate kernel\n");
goto fail_free_cmdline;
}
status = efi_parse_options(cmdline_ptr);
if (status != EFI_SUCCESS)
pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
secure_boot = efi_get_secureboot(sys_table);
if (secure_boot > 0)
pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
if (secure_boot < 0) {
pr_efi_err(sys_table,
"could not determine UEFI Secure Boot status.\n");
}
/*
* Unauthenticated device tree data is a security hazard, so
* ignore 'dtb=' unless UEFI Secure Boot is disabled.
*/
if (secure_boot != 0 && strstr(cmdline_ptr, "dtb=")) {
pr_efi(sys_table, "Ignoring DTB from command line.\n");
} else {
status = handle_cmdline_files(sys_table, image, cmdline_ptr,
"dtb=",
~0UL, &fdt_addr, &fdt_size);
if (status != EFI_SUCCESS) {
pr_efi_err(sys_table, "Failed to load device tree!\n");
goto fail_free_image;
}
}
if (fdt_addr) {
pr_efi(sys_table, "Using DTB from command line\n");
} else {
/* Look for a device tree configuration table entry. */
fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
if (fdt_addr)
pr_efi(sys_table, "Using DTB from configuration table\n");
}
if (!fdt_addr)
pr_efi(sys_table, "Generating empty DTB\n");
status = handle_cmdline_files(sys_table, image, cmdline_ptr,
"initrd=", dram_base + SZ_512M,
(unsigned long *)&initrd_addr,
(unsigned long *)&initrd_size);
if (status != EFI_SUCCESS)
pr_efi_err(sys_table, "Failed initrd from command line!\n");
efi_random_get_seed(sys_table);
new_fdt_addr = fdt_addr;
status = allocate_new_fdt_and_exit_boot(sys_table, handle,
&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
initrd_addr, initrd_size, cmdline_ptr,
fdt_addr, fdt_size);
/*
* If all went well, we need to return the FDT address to the
* calling function so it can be passed to kernel as part of
* the kernel boot protocol.
*/
if (status == EFI_SUCCESS)
return new_fdt_addr;
pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
efi_free(sys_table, initrd_size, initrd_addr);
efi_free(sys_table, fdt_size, fdt_addr);
fail_free_image:
efi_free(sys_table, image_size, *image_addr);
efi_free(sys_table, reserve_size, reserve_addr);
fail_free_cmdline:
free_screen_info(sys_table, si);
efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
fail:
return EFI_ERROR;
}
/*
* Because the x86 boot code expects to be passed a boot_params we
* need to create one ourselves (usually the bootloader would create
* one for us).
*
* The caller is responsible for filling out ->code32_start in the
* returned boot_params.
*/
struct boot_params *make_boot_params(struct efi_config *c)
{
struct boot_params *boot_params;
struct apm_bios_info *bi;
struct setup_header *hdr;
efi_loaded_image_t *image;
void *options, *handle;
efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
int options_size = 0;
efi_status_t status;
char *cmdline_ptr;
u16 *s2;
u8 *s1;
int i;
unsigned long ramdisk_addr;
unsigned long ramdisk_size;
efi_early = c;
sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
handle = (void *)(unsigned long)efi_early->image_handle;
/* Check if we were booted by the EFI firmware */
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
return NULL;
if (efi_early->is64)
setup_boot_services64(efi_early);
else
setup_boot_services32(efi_early);
status = efi_call_early(handle_protocol, handle,
&proto, (void *)&image);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
return NULL;
}
status = efi_low_alloc(sys_table, 0x4000, 1,
(unsigned long *)&boot_params);
if (status != EFI_SUCCESS) {
efi_printk(sys_table, "Failed to alloc lowmem for boot params\n");
return NULL;
}
memset(boot_params, 0x0, 0x4000);
hdr = &boot_params->hdr;
bi = &boot_params->apm_bios_info;
/* Copy the second sector to boot_params */
memcpy(&hdr->jump, image->image_base + 512, 512);
/*
* Fill out some of the header fields ourselves because the
* EFI firmware loader doesn't load the first sector.
*/
hdr->root_flags = 1;
hdr->vid_mode = 0xffff;
hdr->boot_flag = 0xAA55;
hdr->type_of_loader = 0x21;
/* Convert unicode cmdline to ascii */
cmdline_ptr = efi_convert_cmdline(sys_table, image, &options_size);
if (!cmdline_ptr)
goto fail;
hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
/* Fill in upper bits of command line address, NOP on 32 bit */
boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
hdr->ramdisk_image = 0;
hdr->ramdisk_size = 0;
/* Clear APM BIOS info */
memset(bi, 0, sizeof(*bi));
status = efi_parse_options(cmdline_ptr);
if (status != EFI_SUCCESS)
goto fail2;
status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", hdr->initrd_addr_max,
&ramdisk_addr, &ramdisk_size);
if (status != EFI_SUCCESS &&
hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
efi_printk(sys_table, "Trying to load files to higher address\n");
status = handle_cmdline_files(sys_table, image,
(char *)(unsigned long)hdr->cmd_line_ptr,
"initrd=", -1UL,
&ramdisk_addr, &ramdisk_size);
}
if (status != EFI_SUCCESS)
goto fail2;
hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
hdr->ramdisk_size = ramdisk_size & 0xffffffff;
boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
boot_params->ext_ramdisk_size = (u64)ramdisk_size >> 32;
return boot_params;
fail2:
efi_free(sys_table, options_size, hdr->cmd_line_ptr);
fail:
efi_free(sys_table, 0x4000, (unsigned long)boot_params);
return NULL;
}