2 * FDT related Helper functions used by the EFI stub on multiple
3 * architectures. This should be #included by the EFI stub
4 * implementation files.
6 * Copyright 2013 Linaro Limited; author Roy Franz
8 * This file is part of the Linux kernel, and is made available
9 * under the terms of the GNU General Public License version 2.
13 #include <linux/efi.h>
14 #include <linux/libfdt.h>
19 efi_status_t
update_fdt(efi_system_table_t
*sys_table
, void *orig_fdt
,
20 unsigned long orig_fdt_size
,
21 void *fdt
, int new_fdt_size
, char *cmdline_ptr
,
22 u64 initrd_addr
, u64 initrd_size
,
23 efi_memory_desc_t
*memory_map
,
24 unsigned long map_size
, unsigned long desc_size
,
32 /* Do some checks on provided FDT, if it exists*/
34 if (fdt_check_header(orig_fdt
)) {
35 pr_efi_err(sys_table
, "Device Tree header not valid!\n");
36 return EFI_LOAD_ERROR
;
39 * We don't get the size of the FDT if we get if from a
40 * configuration table.
42 if (orig_fdt_size
&& fdt_totalsize(orig_fdt
) > orig_fdt_size
) {
43 pr_efi_err(sys_table
, "Truncated device tree! foo!\n");
44 return EFI_LOAD_ERROR
;
49 status
= fdt_open_into(orig_fdt
, fdt
, new_fdt_size
);
51 status
= fdt_create_empty_tree(fdt
, new_fdt_size
);
57 * Delete all memory reserve map entries. When booting via UEFI,
58 * kernel will use the UEFI memory map to find reserved regions.
60 num_rsv
= fdt_num_mem_rsv(fdt
);
62 fdt_del_mem_rsv(fdt
, num_rsv
);
64 node
= fdt_subnode_offset(fdt
, 0, "chosen");
66 node
= fdt_add_subnode(fdt
, 0, "chosen");
68 status
= node
; /* node is error code when negative */
73 if ((cmdline_ptr
!= NULL
) && (strlen(cmdline_ptr
) > 0)) {
74 status
= fdt_setprop(fdt
, node
, "bootargs", cmdline_ptr
,
75 strlen(cmdline_ptr
) + 1);
80 /* Set initrd address/end in device tree, if present */
81 if (initrd_size
!= 0) {
83 u64 initrd_image_start
= cpu_to_fdt64(initrd_addr
);
85 status
= fdt_setprop(fdt
, node
, "linux,initrd-start",
86 &initrd_image_start
, sizeof(u64
));
89 initrd_image_end
= cpu_to_fdt64(initrd_addr
+ initrd_size
);
90 status
= fdt_setprop(fdt
, node
, "linux,initrd-end",
91 &initrd_image_end
, sizeof(u64
));
96 /* Add FDT entries for EFI runtime services in chosen node. */
97 node
= fdt_subnode_offset(fdt
, 0, "chosen");
98 fdt_val64
= cpu_to_fdt64((u64
)(unsigned long)sys_table
);
99 status
= fdt_setprop(fdt
, node
, "linux,uefi-system-table",
100 &fdt_val64
, sizeof(fdt_val64
));
104 fdt_val64
= cpu_to_fdt64((u64
)(unsigned long)memory_map
);
105 status
= fdt_setprop(fdt
, node
, "linux,uefi-mmap-start",
106 &fdt_val64
, sizeof(fdt_val64
));
110 fdt_val32
= cpu_to_fdt32(map_size
);
111 status
= fdt_setprop(fdt
, node
, "linux,uefi-mmap-size",
112 &fdt_val32
, sizeof(fdt_val32
));
116 fdt_val32
= cpu_to_fdt32(desc_size
);
117 status
= fdt_setprop(fdt
, node
, "linux,uefi-mmap-desc-size",
118 &fdt_val32
, sizeof(fdt_val32
));
122 fdt_val32
= cpu_to_fdt32(desc_ver
);
123 status
= fdt_setprop(fdt
, node
, "linux,uefi-mmap-desc-ver",
124 &fdt_val32
, sizeof(fdt_val32
));
128 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE
)) {
129 efi_status_t efi_status
;
131 efi_status
= efi_get_random_bytes(sys_table
, sizeof(fdt_val64
),
133 if (efi_status
== EFI_SUCCESS
) {
134 status
= fdt_setprop(fdt
, node
, "kaslr-seed",
135 &fdt_val64
, sizeof(fdt_val64
));
138 } else if (efi_status
!= EFI_NOT_FOUND
) {
145 if (status
== -FDT_ERR_NOSPACE
)
146 return EFI_BUFFER_TOO_SMALL
;
148 return EFI_LOAD_ERROR
;
151 #ifndef EFI_FDT_ALIGN
152 #define EFI_FDT_ALIGN EFI_PAGE_SIZE
156 * Allocate memory for a new FDT, then add EFI, commandline, and
157 * initrd related fields to the FDT. This routine increases the
158 * FDT allocation size until the allocated memory is large
159 * enough. EFI allocations are in EFI_PAGE_SIZE granules,
160 * which are fixed at 4K bytes, so in most cases the first
161 * allocation should succeed.
162 * EFI boot services are exited at the end of this function.
163 * There must be no allocations between the get_memory_map()
164 * call and the exit_boot_services() call, so the exiting of
165 * boot services is very tightly tied to the creation of the FDT
166 * with the final memory map in it.
169 efi_status_t
allocate_new_fdt_and_exit_boot(efi_system_table_t
*sys_table
,
171 unsigned long *new_fdt_addr
,
172 unsigned long max_addr
,
173 u64 initrd_addr
, u64 initrd_size
,
175 unsigned long fdt_addr
,
176 unsigned long fdt_size
)
178 unsigned long map_size
, desc_size
;
180 unsigned long mmap_key
;
181 efi_memory_desc_t
*memory_map
, *runtime_map
;
182 unsigned long new_fdt_size
;
184 int runtime_entry_count
= 0;
187 * Get a copy of the current memory map that we will use to prepare
188 * the input for SetVirtualAddressMap(). We don't have to worry about
189 * subsequent allocations adding entries, since they could not affect
190 * the number of EFI_MEMORY_RUNTIME regions.
192 status
= efi_get_memory_map(sys_table
, &runtime_map
, &map_size
,
193 &desc_size
, &desc_ver
, &mmap_key
);
194 if (status
!= EFI_SUCCESS
) {
195 pr_efi_err(sys_table
, "Unable to retrieve UEFI memory map.\n");
200 "Exiting boot services and installing virtual address map...\n");
203 * Estimate size of new FDT, and allocate memory for it. We
204 * will allocate a bigger buffer if this ends up being too
205 * small, so a rough guess is OK here.
207 new_fdt_size
= fdt_size
+ EFI_PAGE_SIZE
;
209 status
= efi_high_alloc(sys_table
, new_fdt_size
, EFI_FDT_ALIGN
,
210 new_fdt_addr
, max_addr
);
211 if (status
!= EFI_SUCCESS
) {
212 pr_efi_err(sys_table
, "Unable to allocate memory for new device tree.\n");
217 * Now that we have done our final memory allocation (and free)
218 * we can get the memory map key needed for
219 * exit_boot_services().
221 status
= efi_get_memory_map(sys_table
, &memory_map
, &map_size
,
222 &desc_size
, &desc_ver
, &mmap_key
);
223 if (status
!= EFI_SUCCESS
)
224 goto fail_free_new_fdt
;
226 status
= update_fdt(sys_table
,
227 (void *)fdt_addr
, fdt_size
,
228 (void *)*new_fdt_addr
, new_fdt_size
,
229 cmdline_ptr
, initrd_addr
, initrd_size
,
230 memory_map
, map_size
, desc_size
, desc_ver
);
232 /* Succeeding the first time is the expected case. */
233 if (status
== EFI_SUCCESS
)
236 if (status
== EFI_BUFFER_TOO_SMALL
) {
238 * We need to allocate more space for the new
239 * device tree, so free existing buffer that is
240 * too small. Also free memory map, as we will need
241 * to get new one that reflects the free/alloc we do
242 * on the device tree buffer.
244 efi_free(sys_table
, new_fdt_size
, *new_fdt_addr
);
245 sys_table
->boottime
->free_pool(memory_map
);
246 new_fdt_size
+= EFI_PAGE_SIZE
;
248 pr_efi_err(sys_table
, "Unable to construct new device tree.\n");
254 * Update the memory map with virtual addresses. The function will also
255 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
256 * entries so that we can pass it straight into SetVirtualAddressMap()
258 efi_get_virtmap(memory_map
, map_size
, desc_size
, runtime_map
,
259 &runtime_entry_count
);
261 /* Now we are ready to exit_boot_services.*/
262 status
= sys_table
->boottime
->exit_boot_services(handle
, mmap_key
);
264 if (status
== EFI_SUCCESS
) {
265 efi_set_virtual_address_map_t
*svam
;
267 /* Install the new virtual address map */
268 svam
= sys_table
->runtime
->set_virtual_address_map
;
269 status
= svam(runtime_entry_count
* desc_size
, desc_size
,
270 desc_ver
, runtime_map
);
273 * We are beyond the point of no return here, so if the call to
274 * SetVirtualAddressMap() failed, we need to signal that to the
275 * incoming kernel but proceed normally otherwise.
277 if (status
!= EFI_SUCCESS
) {
281 * Set the virtual address field of all
282 * EFI_MEMORY_RUNTIME entries to 0. This will signal
283 * the incoming kernel that no virtual translation has
286 for (l
= 0; l
< map_size
; l
+= desc_size
) {
287 efi_memory_desc_t
*p
= (void *)memory_map
+ l
;
289 if (p
->attribute
& EFI_MEMORY_RUNTIME
)
296 pr_efi_err(sys_table
, "Exit boot services failed.\n");
299 sys_table
->boottime
->free_pool(memory_map
);
302 efi_free(sys_table
, new_fdt_size
, *new_fdt_addr
);
305 sys_table
->boottime
->free_pool(runtime_map
);
306 return EFI_LOAD_ERROR
;
309 void *get_fdt(efi_system_table_t
*sys_table
, unsigned long *fdt_size
)
311 efi_guid_t fdt_guid
= DEVICE_TREE_GUID
;
312 efi_config_table_t
*tables
;
316 tables
= (efi_config_table_t
*) sys_table
->tables
;
319 for (i
= 0; i
< sys_table
->nr_tables
; i
++)
320 if (efi_guidcmp(tables
[i
].guid
, fdt_guid
) == 0) {
321 fdt
= (void *) tables
[i
].table
;
322 if (fdt_check_header(fdt
) != 0) {
323 pr_efi_err(sys_table
, "Invalid header detected on UEFI supplied FDT, ignoring ...\n");
326 *fdt_size
= fdt_totalsize(fdt
);