drivers/firmware/efi/libstub/arm64-stub.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2013, 2014 Linaro Ltd;  <roy.franz@linaro.org>
 *
 * This file implements the EFI boot stub for the arm64 kernel.
 * Adapted from ARM version by Mark Salter <msalter@redhat.com>
 */


#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/memory.h>
#include <asm/sections.h>

#include "efistub.h"

efi_status_t handle_kernel_image(unsigned long *image_addr,
				 unsigned long *image_size,
				 unsigned long *reserve_addr,
				 unsigned long *reserve_size,
				 efi_loaded_image_t *image,
				 efi_handle_t image_handle)
{
	efi_status_t status;
	unsigned long kernel_size, kernel_codesize, kernel_memsize;

	if (image->image_base != _text) {
		efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
		image->image_base = _text;
	}

	if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN))
		efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n",
			SEGMENT_ALIGN >> 10);

	kernel_size = _edata - _text;
	kernel_codesize = __inittext_end - _text;
	kernel_memsize = kernel_size + (_end - _edata);
	*reserve_size = kernel_memsize;
	*image_addr = (unsigned long)_text;

	status = efi_kaslr_relocate_kernel(image_addr,
					   reserve_addr, reserve_size,
					   kernel_size, kernel_codesize,
					   kernel_memsize,
					   efi_kaslr_get_phys_seed(image_handle));
	if (status != EFI_SUCCESS)
		return status;

	return EFI_SUCCESS;
}

asmlinkage void primary_entry(void);

unsigned long primary_entry_offset(void)
{
	/*
	 * When built as part of the kernel, the EFI stub cannot branch to the
	 * kernel proper via the image header, as the PE/COFF header is
	 * strictly not part of the in-memory presentation of the image, only
	 * of the file representation. So instead, we need to jump to the
	 * actual entrypoint in the .text region of the image.
	 */
	return (char *)primary_entry - _text;
}

void efi_icache_sync(unsigned long start, unsigned long end)
{
	caches_clean_inval_pou(start, end);
}