xref: /linux/drivers/firmware/efi/libstub/efi-stub-entry.c (revision c5a8f13f1e476c90f4bc184a58751d3e7ff88f2b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/efi.h>
4 #include <linux/sysfb.h>
5 
6 #include <asm/efi.h>
7 
8 #include "efistub.h"
9 
10 static unsigned long kernel_image_offset;
11 
12 static void *kernel_image_addr(void *addr)
13 {
14 	return addr + kernel_image_offset;
15 }
16 
17 struct sysfb_display_info *alloc_primary_display(void)
18 {
19 	if (IS_ENABLED(CONFIG_ARM))
20 		return __alloc_primary_display();
21 
22 	if (IS_ENABLED(CONFIG_X86) ||
23 	    IS_ENABLED(CONFIG_EFI_EARLYCON) ||
24 	    IS_ENABLED(CONFIG_SYSFB))
25 		return kernel_image_addr(&sysfb_primary_display);
26 
27 	return NULL;
28 }
29 
30 /*
31  * EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and
32  * LoongArch. This is the entrypoint that is described in the PE/COFF header
33  * of the core kernel.
34  */
35 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
36 				   efi_system_table_t *systab)
37 {
38 	efi_loaded_image_t *image;
39 	efi_status_t status;
40 	unsigned long image_addr;
41 	unsigned long image_size = 0;
42 	/* addr/point and size pairs for memory management*/
43 	char *cmdline_ptr = NULL;
44 	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
45 	unsigned long reserve_addr = 0;
46 	unsigned long reserve_size = 0;
47 
48 	WRITE_ONCE(efi_system_table, systab);
49 
50 	/* Check if we were booted by the EFI firmware */
51 	if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
52 		return EFI_INVALID_PARAMETER;
53 
54 	/*
55 	 * Get a handle to the loaded image protocol.  This is used to get
56 	 * information about the running image, such as size and the command
57 	 * line.
58 	 */
59 	status = efi_bs_call(handle_protocol, handle, &loaded_image_proto,
60 			     (void *)&image);
61 	if (status != EFI_SUCCESS) {
62 		efi_err("Failed to get loaded image protocol\n");
63 		return status;
64 	}
65 
66 	status = efi_handle_cmdline(image, &cmdline_ptr);
67 	if (status != EFI_SUCCESS)
68 		return status;
69 
70 	efi_info("Booting Linux Kernel...\n");
71 
72 	status = handle_kernel_image(&image_addr, &image_size,
73 				     &reserve_addr,
74 				     &reserve_size,
75 				     image, handle);
76 	if (status != EFI_SUCCESS) {
77 		efi_err("Failed to relocate kernel\n");
78 		return status;
79 	}
80 
81 	kernel_image_offset = image_addr - (unsigned long)image->image_base;
82 
83 	status = efi_stub_common(handle, image, image_addr, cmdline_ptr);
84 
85 	efi_free(image_size, image_addr);
86 	efi_free(reserve_size, reserve_addr);
87 
88 	return status;
89 }
90