xref: /linux/drivers/firmware/efi/libstub/riscv-stub.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020 Western Digital Corporation or its affiliates.
4  */
5 
6 #include <linux/efi.h>
7 
8 #include <asm/efi.h>
9 #include <asm/sections.h>
10 #include <asm/unaligned.h>
11 
12 #include "efistub.h"
13 
14 unsigned long stext_offset(void)
15 {
16 	/*
17 	 * When built as part of the kernel, the EFI stub cannot branch to the
18 	 * kernel proper via the image header, as the PE/COFF header is
19 	 * strictly not part of the in-memory presentation of the image, only
20 	 * of the file representation. So instead, we need to jump to the
21 	 * actual entrypoint in the .text region of the image.
22 	 */
23 	return _start_kernel - _start;
24 }
25 
26 efi_status_t handle_kernel_image(unsigned long *image_addr,
27 				 unsigned long *image_size,
28 				 unsigned long *reserve_addr,
29 				 unsigned long *reserve_size,
30 				 efi_loaded_image_t *image,
31 				 efi_handle_t image_handle)
32 {
33 	unsigned long kernel_size, kernel_codesize, kernel_memsize;
34 	efi_status_t status;
35 
36 	kernel_size = _edata - _start;
37 	kernel_codesize = __init_text_end - _start;
38 	kernel_memsize = kernel_size + (_end - _edata);
39 	*image_addr = (unsigned long)_start;
40 	*image_size = kernel_memsize;
41 	*reserve_size = *image_size;
42 
43 	status = efi_kaslr_relocate_kernel(image_addr,
44 					   reserve_addr, reserve_size,
45 					   kernel_size, kernel_codesize, kernel_memsize,
46 					   efi_kaslr_get_phys_seed(image_handle));
47 	if (status != EFI_SUCCESS) {
48 		efi_err("Failed to relocate kernel\n");
49 		*image_size = 0;
50 	}
51 
52 	return status;
53 }
54 
55 void efi_icache_sync(unsigned long start, unsigned long end)
56 {
57 	asm volatile ("fence.i" ::: "memory");
58 }
59