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

Source file repositories/reference/linux-study-clean/drivers/firmware/efi/libstub/riscv-stub.c

File Facts

System
Linux kernel
Corpus path
drivers/firmware/efi/libstub/riscv-stub.c
Extension
.c
Size
1587 bytes
Lines
59
Domain
Driver Families
Bucket
drivers/firmware
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 Western Digital Corporation or its affiliates.
 */

#include <linux/efi.h>

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

#include "efistub.h"

unsigned long stext_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 _start_kernel - _start;
}

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)
{
	unsigned long kernel_size, kernel_codesize, kernel_memsize;
	efi_status_t status;

	kernel_size = _edata - _start;
	kernel_codesize = __init_text_end - _start;
	kernel_memsize = kernel_size + (_end - _edata);
	*image_addr = (unsigned long)_start;
	*image_size = kernel_memsize;
	*reserve_size = *image_size;

	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) {
		efi_err("Failed to relocate kernel\n");
		*image_size = 0;
	}

	return status;
}

void efi_icache_sync(unsigned long start, unsigned long end)
{
	asm volatile ("fence.i" ::: "memory");
}

Annotation

Implementation Notes