summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/arm-stub.c
blob: 41114ce03b014cc6c17195ee02ce000a808f7705 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * EFI stub implementation that is shared by arm and arm64 architectures.
 * This should be #included by the EFI stub implementation files.
 *
 * Copyright (C) 2013,2014 Linaro Limited
 *     Roy Franz <roy.franz@linaro.org
 * Copyright (C) 2013 Red Hat, Inc.
 *     Mark Salter <msalter@redhat.com>
 *
 * This file is part of the Linux kernel, and is made available under the
 * terms of the GNU General Public License version 2.
 *
 */

static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
	static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
	static efi_char16_t const var_name[] __initconst = {
		'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };

	efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
	unsigned long size = sizeof(u8);
	efi_status_t status;
	u8 val;

	status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid,
			  NULL, &size, &val);

	switch (status) {
	case EFI_SUCCESS:
		return val;
	case EFI_NOT_FOUND:
		return 0;
	default:
		return 1;
	}
}

static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
				    void *__image, void **__fh)
{
	efi_file_io_interface_t *io;
	efi_loaded_image_t *image = __image;
	efi_file_handle_t *fh;
	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
	efi_status_t status;
	void *handle = (void *)(unsigned long)image->device_handle;

	status = sys_table_arg->boottime->handle_protocol(handle,
				 &fs_proto, (void **)&io);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
		return status;
	}

	status = io->open_volume(io, &fh);
	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to open volume\n");

	*__fh = fh;
	return status;
}
static efi_status_t efi_file_close(void *handle)
{
	efi_file_handle_t *fh = handle;

	return fh->close(handle);
}

static efi_status_t
efi_file_read(void *handle, unsigned long *size, void *addr)
{
	efi_file_handle_t *fh = handle;

	return fh->read(handle, size, addr);
}


static efi_status_t
efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
	      efi_char16_t *filename_16, void **handle, u64 *file_sz)
{
	efi_file_handle_t *h, *fh = __fh;
	efi_file_info_t *info;
	efi_status_t status;
	efi_guid_t info_guid = EFI_FILE_INFO_ID;
	unsigned long info_sz;

	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to open file: ");
		efi_char16_printk(sys_table_arg, filename_16);
		efi_printk(sys_table_arg, "\n");
		return status;
	}

	*handle = h;

	info_sz = 0;
	status = h->get_info(h, &info_guid, &info_sz, NULL);
	if (status != EFI_BUFFER_TOO_SMALL) {
		efi_printk(sys_table_arg, "Failed to get file info size\n");
		return status;
	}

grow:
	status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
				 info_sz, (void **)&info);
	if (status != EFI_SUCCESS) {
		efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
		return status;
	}

	status = h->get_info(h, &info_guid, &info_sz,
						   info);
	if (status == EFI_BUFFER_TOO_SMALL) {
		sys_table_arg->boottime->free_pool(info);
		goto grow;
	}

	*file_sz = info->file_size;
	sys_table_arg->boottime->free_pool(info);

	if (status != EFI_SUCCESS)
		efi_printk(sys_table_arg, "Failed to get initrd info\n");

	return status;
}



static void efi_char16_printk(efi_system_table_t *sys_table_arg,
			      efi_char16_t *str)
{
	struct efi_simple_text_output_protocol *out;

	out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
	out->output_string(out, str);
}


/*
 * This function handles the architcture specific differences between arm and
 * arm64 regarding where the kernel image must be loaded and any memory that
 * must be reserved. On failure it is required to free all
 * all allocations it has made.
 */
static efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
					unsigned long *image_addr,
					unsigned long *image_size,
					unsigned long *reserve_addr,
					unsigned long *reserve_size,
					unsigned long dram_base,
					efi_loaded_image_t *image);
/*
 * EFI entry point for the arm/arm64 EFI stubs.  This is the entrypoint
 * that is described in the PE/COFF header.  Most of the code is the same
 * for both archictectures, with the arch-specific code provided in the
 * handle_kernel_image() function.
 */
unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table,
			       unsigned long *image_addr)
{
	efi_loaded_image_t *image;
	efi_status_t status;
	unsigned long image_size = 0;
	unsigned long dram_base;
	/* addr/point and size pairs for memory management*/
	unsigned long initrd_addr;
	u64 initrd_size = 0;
	unsigned long fdt_addr = 0;  /* Original DTB */
	u64 fdt_size = 0;  /* We don't get size from configuration table */
	char *cmdline_ptr = NULL;
	int cmdline_size = 0;
	unsigned long new_fdt_addr;
	efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
	unsigned long reserve_addr = 0;
	unsigned long reserve_size = 0;

	/* Check if we were booted by the EFI firmware */
	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
		goto fail;

	pr_efi(sys_table, "Booting Linux Kernel...\n");

	/*
	 * Get a handle to the loaded image protocol.  This is used to get
	 * information about the running image, such as size and the command
	 * line.
	 */
	status = sys_table->boottime->handle_protocol(handle,
					&loaded_image_proto, (void *)&image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
		goto fail;
	}

	dram_base = get_dram_base(sys_table);
	if (dram_base == EFI_ERROR) {
		pr_efi_err(sys_table, "Failed to find DRAM base\n");
		goto fail;
	}
	status = handle_kernel_image(sys_table, image_addr, &image_size,
				     &reserve_addr,
				     &reserve_size,
				     dram_base, image);
	if (status != EFI_SUCCESS) {
		pr_efi_err(sys_table, "Failed to relocate kernel\n");
		goto fail;
	}

	/*
	 * Get the command line from EFI, using the LOADED_IMAGE
	 * protocol. We are going to copy the command line into the
	 * device tree, so this can be allocated anywhere.
	 */
	cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
	if (!cmdline_ptr) {
		pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
		goto fail_free_image;
	}

	/*
	 * Unauthenticated device tree data is a security hazard, so
	 * ignore 'dtb=' unless UEFI Secure Boot is disabled.
	 */
	if (efi_secureboot_enabled(sys_table)) {
		pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
	} else {
		status = handle_cmdline_files(sys_table, image, cmdline_ptr,
					      "dtb=",
					      ~0UL, (unsigned long *)&fdt_addr,
					      (unsigned long *)&fdt_size);

		if (status != EFI_SUCCESS) {
			pr_efi_err(sys_table, "Failed to load device tree!\n");
			goto fail_free_cmdline;
		}
	}
	if (!fdt_addr)
		/* Look for a device tree configuration table entry. */
		fdt_addr = (uintptr_t)get_fdt(sys_table);

	status = handle_cmdline_files(sys_table, image, cmdline_ptr,
				      "initrd=", dram_base + SZ_512M,
				      (unsigned long *)&initrd_addr,
				      (unsigned long *)&initrd_size);
	if (status != EFI_SUCCESS)
		pr_efi_err(sys_table, "Failed initrd from command line!\n");

	new_fdt_addr = fdt_addr;
	status = allocate_new_fdt_and_exit_boot(sys_table, handle,
				&new_fdt_addr, dram_base + MAX_FDT_OFFSET,
				initrd_addr, initrd_size, cmdline_ptr,
				fdt_addr, fdt_size);

	/*
	 * If all went well, we need to return the FDT address to the
	 * calling function so it can be passed to kernel as part of
	 * the kernel boot protocol.
	 */
	if (status == EFI_SUCCESS)
		return new_fdt_addr;

	pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");

	efi_free(sys_table, initrd_size, initrd_addr);
	efi_free(sys_table, fdt_size, fdt_addr);

fail_free_cmdline:
	efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);

fail_free_image:
	efi_free(sys_table, image_size, *image_addr);
	efi_free(sys_table, reserve_size, reserve_addr);
fail:
	return EFI_ERROR;
}