summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/efi/fdt.c
blob: 507a3df46a5dabba812a647077a752a56fd7116c (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
/*
 * FDT related Helper functions used by the EFI stub on multiple
 * architectures. This should be #included by the EFI stub
 * implementation files.
 *
 * Copyright 2013 Linaro Limited; author Roy Franz
 *
 * This file is part of the Linux kernel, and is made available
 * under the terms of the GNU General Public License version 2.
 *
 */

static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
			       unsigned long orig_fdt_size,
			       void *fdt, int new_fdt_size, char *cmdline_ptr,
			       u64 initrd_addr, u64 initrd_size,
			       efi_memory_desc_t *memory_map,
			       unsigned long map_size, unsigned long desc_size,
			       u32 desc_ver)
{
	int node, prev;
	int status;
	u32 fdt_val32;
	u64 fdt_val64;

	/* Do some checks on provided FDT, if it exists*/
	if (orig_fdt) {
		if (fdt_check_header(orig_fdt)) {
			pr_efi_err(sys_table, "Device Tree header not valid!\n");
			return EFI_LOAD_ERROR;
		}
		/*
		 * We don't get the size of the FDT if we get if from a
		 * configuration table.
		 */
		if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
			pr_efi_err(sys_table, "Truncated device tree! foo!\n");
			return EFI_LOAD_ERROR;
		}
	}

	if (orig_fdt)
		status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
	else
		status = fdt_create_empty_tree(fdt, new_fdt_size);

	if (status != 0)
		goto fdt_set_fail;

	/*
	 * Delete any memory nodes present. We must delete nodes which
	 * early_init_dt_scan_memory may try to use.
	 */
	prev = 0;
	for (;;) {
		const char *type;
		int len;

		node = fdt_next_node(fdt, prev, NULL);
		if (node < 0)
			break;

		type = fdt_getprop(fdt, node, "device_type", &len);
		if (type && strncmp(type, "memory", len) == 0) {
			fdt_del_node(fdt, node);
			continue;
		}

		prev = node;
	}

	node = fdt_subnode_offset(fdt, 0, "chosen");
	if (node < 0) {
		node = fdt_add_subnode(fdt, 0, "chosen");
		if (node < 0) {
			status = node; /* node is error code when negative */
			goto fdt_set_fail;
		}
	}

	if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) {
		status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
				     strlen(cmdline_ptr) + 1);
		if (status)
			goto fdt_set_fail;
	}

	/* Set initrd address/end in device tree, if present */
	if (initrd_size != 0) {
		u64 initrd_image_end;
		u64 initrd_image_start = cpu_to_fdt64(initrd_addr);

		status = fdt_setprop(fdt, node, "linux,initrd-start",
				     &initrd_image_start, sizeof(u64));
		if (status)
			goto fdt_set_fail;
		initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size);
		status = fdt_setprop(fdt, node, "linux,initrd-end",
				     &initrd_image_end, sizeof(u64));
		if (status)
			goto fdt_set_fail;
	}

	/* Add FDT entries for EFI runtime services in chosen node. */
	node = fdt_subnode_offset(fdt, 0, "chosen");
	fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table);
	status = fdt_setprop(fdt, node, "linux,uefi-system-table",
			     &fdt_val64, sizeof(fdt_val64));
	if (status)
		goto fdt_set_fail;

	fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map);
	status = fdt_setprop(fdt, node, "linux,uefi-mmap-start",
			     &fdt_val64,  sizeof(fdt_val64));
	if (status)
		goto fdt_set_fail;

	fdt_val32 = cpu_to_fdt32(map_size);
	status = fdt_setprop(fdt, node, "linux,uefi-mmap-size",
			     &fdt_val32,  sizeof(fdt_val32));
	if (status)
		goto fdt_set_fail;

	fdt_val32 = cpu_to_fdt32(desc_size);
	status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size",
			     &fdt_val32, sizeof(fdt_val32));
	if (status)
		goto fdt_set_fail;

	fdt_val32 = cpu_to_fdt32(desc_ver);
	status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver",
			     &fdt_val32, sizeof(fdt_val32));
	if (status)
		goto fdt_set_fail;

	/*
	 * Add kernel version banner so stub/kernel match can be
	 * verified.
	 */
	status = fdt_setprop_string(fdt, node, "linux,uefi-stub-kern-ver",
			     linux_banner);
	if (status)
		goto fdt_set_fail;

	return EFI_SUCCESS;

fdt_set_fail:
	if (status == -FDT_ERR_NOSPACE)
		return EFI_BUFFER_TOO_SMALL;

	return EFI_LOAD_ERROR;
}

#ifndef EFI_FDT_ALIGN
#define EFI_FDT_ALIGN EFI_PAGE_SIZE
#endif

/*
 * Allocate memory for a new FDT, then add EFI, commandline, and
 * initrd related fields to the FDT.  This routine increases the
 * FDT allocation size until the allocated memory is large
 * enough.  EFI allocations are in EFI_PAGE_SIZE granules,
 * which are fixed at 4K bytes, so in most cases the first
 * allocation should succeed.
 * EFI boot services are exited at the end of this function.
 * There must be no allocations between the get_memory_map()
 * call and the exit_boot_services() call, so the exiting of
 * boot services is very tightly tied to the creation of the FDT
 * with the final memory map in it.
 */

efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
					    void *handle,
					    unsigned long *new_fdt_addr,
					    unsigned long max_addr,
					    u64 initrd_addr, u64 initrd_size,
					    char *cmdline_ptr,
					    unsigned long fdt_addr,
					    unsigned long fdt_size)
{
	unsigned long map_size, desc_size;
	u32 desc_ver;
	unsigned long mmap_key;
	efi_memory_desc_t *memory_map;
	unsigned long new_fdt_size;
	efi_status_t status;

	/*
	 * Estimate size of new FDT, and allocate memory for it. We
	 * will allocate a bigger buffer if this ends up being too
	 * small, so a rough guess is OK here.
	 */
	new_fdt_size = fdt_size + EFI_PAGE_SIZE;
	while (1) {
		status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN,
					new_fdt_addr, max_addr);
		if (status != EFI_SUCCESS) {
			pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n");
			goto fail;
		}

		/*
		 * Now that we have done our final memory allocation (and free)
		 * we can get the memory map key  needed for
		 * exit_boot_services().
		 */
		status = efi_get_memory_map(sys_table, &memory_map, &map_size,
					    &desc_size, &desc_ver, &mmap_key);
		if (status != EFI_SUCCESS)
			goto fail_free_new_fdt;

		status = update_fdt(sys_table,
				    (void *)fdt_addr, fdt_size,
				    (void *)*new_fdt_addr, new_fdt_size,
				    cmdline_ptr, initrd_addr, initrd_size,
				    memory_map, map_size, desc_size, desc_ver);

		/* Succeeding the first time is the expected case. */
		if (status == EFI_SUCCESS)
			break;

		if (status == EFI_BUFFER_TOO_SMALL) {
			/*
			 * We need to allocate more space for the new
			 * device tree, so free existing buffer that is
			 * too small.  Also free memory map, as we will need
			 * to get new one that reflects the free/alloc we do
			 * on the device tree buffer.
			 */
			efi_free(sys_table, new_fdt_size, *new_fdt_addr);
			sys_table->boottime->free_pool(memory_map);
			new_fdt_size += EFI_PAGE_SIZE;
		} else {
			pr_efi_err(sys_table, "Unable to constuct new device tree.\n");
			goto fail_free_mmap;
		}
	}

	/* Now we are ready to exit_boot_services.*/
	status = sys_table->boottime->exit_boot_services(handle, mmap_key);


	if (status == EFI_SUCCESS)
		return status;

	pr_efi_err(sys_table, "Exit boot services failed.\n");

fail_free_mmap:
	sys_table->boottime->free_pool(memory_map);

fail_free_new_fdt:
	efi_free(sys_table, new_fdt_size, *new_fdt_addr);

fail:
	return EFI_LOAD_ERROR;
}

static void *get_fdt(efi_system_table_t *sys_table)
{
	efi_guid_t fdt_guid = DEVICE_TREE_GUID;
	efi_config_table_t *tables;
	void *fdt;
	int i;

	tables = (efi_config_table_t *) sys_table->tables;
	fdt = NULL;

	for (i = 0; i < sys_table->nr_tables; i++)
		if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
			fdt = (void *) tables[i].table;
			break;
	 }

	return fdt;
}
OpenPOWER on IntegriCloud