Commit 42c8ea3d authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

efi: libstub: Factor out EFI stub entrypoint into separate file 



In preparation for allowing the EFI zboot decompressor to reuse most of
the EFI stub machinery, factor out the actual EFI PE/COFF entrypoint
into a separate file.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent da8dd0c7

drivers/firmware/efi/libstub/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -83,7 +83,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE 
	$(call if_changed_rule,cc_o_c)



lib-$(CONFIG_EFI_GENERIC_STUB)	+= efi-stub.o string.o intrinsics.o systable.o \

				   screen_info.o

				   screen_info.o efi-stub-entry.o



lib-$(CONFIG_ARM)		+= arm32-stub.o

lib-$(CONFIG_ARM64)		+= arm64-stub.o arm64-entry.o

drivers/firmware/efi/libstub/efi-stub-entry.c

0 → 100644
+65 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <linux/efi.h>

#include <asm/efi.h>



#include "efistub.h"



/*

 * EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and

 * LoongArch. This is the entrypoint that is described in the PE/COFF header

 * of the core kernel.

 */

efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,

				   efi_system_table_t *systab)

{

	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*/

	char *cmdline_ptr = NULL;

	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;

	unsigned long reserve_addr = 0;

	unsigned long reserve_size = 0;



	WRITE_ONCE(efi_system_table, systab);



	/* Check if we were booted by the EFI firmware */

	if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)

		return EFI_INVALID_PARAMETER;



	/*

	 * 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_bs_call(handle_protocol, handle, &loaded_image_proto,

			     (void *)&image);

	if (status != EFI_SUCCESS) {

		efi_err("Failed to get loaded image protocol\n");

		return status;

	}



	status = efi_handle_cmdline(image, &cmdline_ptr);

	if (status != EFI_SUCCESS)

		return status;



	efi_info("Booting Linux Kernel...\n");



	status = handle_kernel_image(&image_addr, &image_size,

				     &reserve_addr,

				     &reserve_size,

				     image, handle);

	if (status != EFI_SUCCESS) {

		efi_err("Failed to relocate kernel\n");

		return status;

	}



	status = efi_stub_common(handle, image, image_addr, cmdline_ptr);



	efi_free(image_size, image_addr);

	efi_free(reserve_size, reserve_addr);



	return status;

}

drivers/firmware/efi/libstub/efi-stub.c

+26 −63
Original line number Diff line number Diff line
@@ -115,61 +115,21 @@ static u32 get_supported_rt_services(void) 
	return supported;

}



/*

 * 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.

 */

efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,

				   efi_system_table_t *sys_table_arg)

efi_status_t efi_handle_cmdline(efi_loaded_image_t *image, char **cmdline_ptr)

{

	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*/

	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;

	struct screen_info *si;



	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_bs_call(handle_protocol, handle, &loaded_image_proto,

			     (void *)&image);

	if (status != EFI_SUCCESS) {

		efi_err("Failed to get loaded image protocol\n");

		goto fail;

	}

	efi_status_t status;

	char *cmdline;



	/*

	 * 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) {

	cmdline = efi_convert_cmdline(image, &cmdline_size);

	if (!cmdline) {

		efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");

		status = EFI_OUT_OF_RESOURCES;

		goto fail;

		return EFI_OUT_OF_RESOURCES;

	}



	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
@@ -183,26 +143,35 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 
	}



	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {

		status = efi_parse_options(cmdline_ptr);

		status = efi_parse_options(cmdline);

		if (status != EFI_SUCCESS) {

			efi_err("Failed to parse options\n");

			goto fail_free_cmdline;

		}

	}



	efi_info("Booting Linux Kernel...\n");



	si = setup_graphics();

	*cmdline_ptr = cmdline;

	return EFI_SUCCESS;



	status = handle_kernel_image(&image_addr, &image_size,

				     &reserve_addr,

				     &reserve_size,

				     image, handle);

	if (status != EFI_SUCCESS) {

		efi_err("Failed to relocate kernel\n");

		goto fail_free_screeninfo;

fail_free_cmdline:

	efi_bs_call(free_pool, cmdline_ptr);

	return status;

}



efi_status_t efi_stub_common(efi_handle_t handle,

			     efi_loaded_image_t *image,

			     unsigned long image_addr,

			     char *cmdline_ptr)

{

	struct screen_info *si;

	efi_status_t status;



	status = check_platform_features();

	if (status != EFI_SUCCESS)

		return status;



	si = setup_graphics();



	efi_retrieve_tpm2_eventlog();



	/* Ask the firmware to clear memory on unclean shutdown */
@@ -221,13 +190,7 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, 


	status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr);



	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;

}

drivers/firmware/efi/libstub/efistub.h

+8 −0
Original line number Diff line number Diff line
@@ -958,6 +958,14 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, 
				 efi_loaded_image_t *image,

				 efi_handle_t image_handle);



/* shared entrypoint between the normal stub and the zboot stub */

efi_status_t efi_stub_common(efi_handle_t handle,

			     efi_loaded_image_t *image,

			     unsigned long image_addr,

			     char *cmdline_ptr);



efi_status_t efi_handle_cmdline(efi_loaded_image_t *image, char **cmdline_ptr);



asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,

					    unsigned long fdt_addr,

					    unsigned long fdt_size);