1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/efi.h>
4 #include <asm/efi.h>
5 
6 #include "efistub.h"
7 
8 static unsigned long screen_info_offset;
9 
10 struct screen_info *alloc_screen_info(void)
11 {
12 	if (IS_ENABLED(CONFIG_ARM))
13 		return __alloc_screen_info();
14 	return (void *)&screen_info + screen_info_offset;
15 }
16 
17 /*
18  * EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and
19  * LoongArch. This is the entrypoint that is described in the PE/COFF header
20  * of the core kernel.
21  */
22 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
23 				   efi_system_table_t *systab)
24 {
25 	efi_loaded_image_t *image;
26 	efi_status_t status;
27 	unsigned long image_addr;
28 	unsigned long image_size = 0;
29 	/* addr/point and size pairs for memory management*/
30 	char *cmdline_ptr = NULL;
31 	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
32 	unsigned long reserve_addr = 0;
33 	unsigned long reserve_size = 0;
34 
35 	WRITE_ONCE(efi_system_table, systab);
36 
37 	/* Check if we were booted by the EFI firmware */
38 	if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
39 		return EFI_INVALID_PARAMETER;
40 
41 	/*
42 	 * Get a handle to the loaded image protocol.  This is used to get
43 	 * information about the running image, such as size and the command
44 	 * line.
45 	 */
46 	status = efi_bs_call(handle_protocol, handle, &loaded_image_proto,
47 			     (void *)&image);
48 	if (status != EFI_SUCCESS) {
49 		efi_err("Failed to get loaded image protocol\n");
50 		return status;
51 	}
52 
53 	status = efi_handle_cmdline(image, &cmdline_ptr);
54 	if (status != EFI_SUCCESS)
55 		return status;
56 
57 	efi_info("Booting Linux Kernel...\n");
58 
59 	status = handle_kernel_image(&image_addr, &image_size,
60 				     &reserve_addr,
61 				     &reserve_size,
62 				     image, handle);
63 	if (status != EFI_SUCCESS) {
64 		efi_err("Failed to relocate kernel\n");
65 		return status;
66 	}
67 
68 	screen_info_offset = image_addr - (unsigned long)image->image_base;
69 
70 	status = efi_stub_common(handle, image, image_addr, cmdline_ptr);
71 
72 	efi_free(image_size, image_addr);
73 	efi_free(reserve_size, reserve_addr);
74 
75 	return status;
76 }
77