1 #include "dragonstub/elfloader.h"
2 #include "dragonstub/printk.h"
3 #include "efidef.h"
4 #include <dragonstub/dragonstub.h>
5 #include <libfdt.h>
6 #include <libfdt_internal.h>
7
8 struct exit_boot_struct {
9 struct efi_boot_memmap *boot_memmap;
10 efi_memory_desc_t *runtime_map;
11 int runtime_entry_count;
12 void *new_fdt_addr;
13 };
14
15 #define EFI_DT_ADDR_CELLS_DEFAULT 2
16 #define EFI_DT_SIZE_CELLS_DEFAULT 2
17
fdt_update_cell_size(void * fdt)18 static void fdt_update_cell_size(void *fdt)
19 {
20 int offset;
21
22 offset = fdt_path_offset(fdt, "/");
23 /* Set the #address-cells and #size-cells values for an empty tree */
24
25 fdt_setprop_u32(fdt, offset, "#address-cells",
26 EFI_DT_ADDR_CELLS_DEFAULT);
27 fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT);
28 }
29
update_fdt_memmap(void * fdt,struct efi_boot_memmap * map)30 static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
31 {
32 int node = fdt_path_offset(fdt, "/chosen");
33 u64 fdt_val64;
34 u32 fdt_val32;
35 int err;
36
37 if (node < 0)
38 return EFI_LOAD_ERROR;
39
40 fdt_val64 = cpu_to_fdt64((unsigned long)map->map);
41
42 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start",
43 fdt_val64);
44 if (err)
45 return EFI_LOAD_ERROR;
46
47 fdt_val32 = cpu_to_fdt32(map->map_size);
48
49 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size",
50 fdt_val32);
51 if (err)
52 return EFI_LOAD_ERROR;
53
54 fdt_val32 = cpu_to_fdt32(map->desc_size);
55
56 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size",
57 fdt_val32);
58 if (err)
59 return EFI_LOAD_ERROR;
60
61 fdt_val32 = cpu_to_fdt32(map->desc_ver);
62
63 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver",
64 fdt_val32);
65 if (err)
66 return EFI_LOAD_ERROR;
67
68 return EFI_SUCCESS;
69 }
70
update_fdt(void * orig_fdt,unsigned long orig_fdt_size,void * fdt,int new_fdt_size,char * cmdline_ptr)71 static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
72 void *fdt, int new_fdt_size, char *cmdline_ptr)
73 {
74 int node, num_rsv;
75 int status;
76 u32 fdt_val32;
77 u64 fdt_val64;
78
79 /* Do some checks on provided FDT, if it exists: */
80 if (orig_fdt) {
81 if (fdt_check_header(orig_fdt)) {
82 efi_err("Device Tree header not valid!\n");
83 return EFI_LOAD_ERROR;
84 }
85 /*
86 * We don't get the size of the FDT if we get if from a
87 * configuration table:
88 */
89 if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
90 efi_err("Truncated device tree! foo!\n");
91 return EFI_LOAD_ERROR;
92 }
93 }
94
95 if (orig_fdt) {
96 status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
97 } else {
98 status = fdt_create_empty_tree(fdt, new_fdt_size);
99 if (status == 0) {
100 /*
101 * Any failure from the following function is
102 * non-critical:
103 */
104 fdt_update_cell_size(fdt);
105 }
106 }
107
108 if (status != 0)
109 goto fdt_set_fail;
110
111 /*
112 * Delete all memory reserve map entries. When booting via UEFI,
113 * kernel will use the UEFI memory map to find reserved regions.
114 */
115 num_rsv = fdt_num_mem_rsv(fdt);
116 while (num_rsv-- > 0)
117 fdt_del_mem_rsv(fdt, num_rsv);
118
119 node = fdt_subnode_offset(fdt, 0, "chosen");
120 if (node < 0) {
121 node = fdt_add_subnode(fdt, 0, "chosen");
122 if (node < 0) {
123 /* 'node' is an error code when negative: */
124 status = node;
125 goto fdt_set_fail;
126 }
127 }
128
129 if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) {
130 status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
131 strlen(cmdline_ptr) + 1);
132 if (status)
133 goto fdt_set_fail;
134 }
135
136 /* Add FDT entries for EFI runtime services in chosen node. */
137 node = fdt_subnode_offset(fdt, 0, "chosen");
138 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)ST);
139
140 status = fdt_setprop_var(fdt, node, "linux,uefi-system-table",
141 fdt_val64);
142 if (status)
143 goto fdt_set_fail;
144
145 fdt_val64 = UINT64_MAX; /* placeholder */
146
147 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
148 if (status)
149 goto fdt_set_fail;
150
151 fdt_val32 = UINT32_MAX; /* placeholder */
152
153 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
154 if (status)
155 goto fdt_set_fail;
156
157 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size",
158 fdt_val32);
159 if (status)
160 goto fdt_set_fail;
161
162 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver",
163 fdt_val32);
164 if (status)
165 goto fdt_set_fail;
166
167 bool enalbed_ramdomize_base = false;
168 #ifdef CONFIG_RANDOMIZE_BASE
169 enalbed_ramdomize_base = true;
170 #endif
171 if (enalbed_ramdomize_base && !efi_nokaslr) {
172 efi_status_t efi_status;
173
174 efi_status = efi_get_random_bytes(sizeof(fdt_val64),
175 (u8 *)&fdt_val64);
176 if (efi_status == EFI_SUCCESS) {
177 status = fdt_setprop_var(fdt, node, "kaslr-seed",
178 fdt_val64);
179 if (status)
180 goto fdt_set_fail;
181 }
182 }
183
184 /* Shrink the FDT back to its minimum size: */
185 fdt_pack(fdt);
186
187 return EFI_SUCCESS;
188
189 fdt_set_fail:
190 if (status == -FDT_ERR_NOSPACE)
191 return EFI_BUFFER_TOO_SMALL;
192
193 return EFI_LOAD_ERROR;
194 }
195
exit_boot_func(struct efi_boot_memmap * map,void * priv)196 static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
197 {
198 struct exit_boot_struct *p = priv;
199
200 p->boot_memmap = map;
201
202 /*
203 * Update the memory map with virtual addresses. The function will also
204 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
205 * entries so that we can pass it straight to SetVirtualAddressMap()
206 */
207 efi_get_virtmap(map->map, map->map_size, map->desc_size, p->runtime_map,
208 &p->runtime_entry_count);
209
210 return update_fdt_memmap(p->new_fdt_addr, map);
211 }
212
213 /*
214 * Allocate memory for a new FDT, then add EFI and commandline related fields
215 * to the FDT. This routine increases the FDT allocation size until the
216 * allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE
217 * granules, which are fixed at 4K bytes, so in most cases the first allocation
218 * should succeed. EFI boot services are exited at the end of this function.
219 * There must be no allocations between the get_memory_map() call and the
220 * exit_boot_services() call, so the exiting of boot services is very tightly
221 * tied to the creation of the FDT with the final memory map in it.
222 */
allocate_new_fdt_and_exit_boot(void * handle,efi_loaded_image_t * image,unsigned long * new_fdt_addr,char * cmdline_ptr)223 static efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
224 efi_loaded_image_t *image,
225 unsigned long *new_fdt_addr,
226 char *cmdline_ptr)
227 {
228 unsigned long desc_size;
229 u32 desc_ver;
230 efi_status_t status;
231 struct exit_boot_struct priv = { 0 };
232 unsigned long fdt_addr = 0;
233 unsigned long fdt_size = 0;
234 if (!efi_novamap) {
235 status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
236 &desc_ver);
237 if (status != EFI_SUCCESS) {
238 efi_err("Unable to retrieve UEFI memory map.\n");
239 return status;
240 }
241 }
242 /*
243 * Unauthenticated device tree data is a security hazard, so ignore
244 * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
245 * boot is enabled if we can't determine its state.
246 */
247 bool config_efi_armstub_dtb_loader = false;
248 #ifdef CONFIG_EFI_ARMSTUB_DTB_LOADER
249 config_efi_armstub_dtb_loader = true;
250 #endif
251 print_efi_secureboot_mode(efi_get_secureboot());
252
253 if (!config_efi_armstub_dtb_loader ||
254 efi_get_secureboot() != efi_secureboot_mode_disabled) {
255 if (strstr(cmdline_ptr, "dtb="))
256 efi_err("Ignoring DTB from command line.\n");
257 } else {
258 efi_todo("Load DTB from command line\n");
259 // status = efi_load_dtb(image, &fdt_addr, &fdt_size);
260
261 // if (status != EFI_SUCCESS && status != EFI_NOT_READY) {
262 // efi_err("Failed to load device tree!\n");
263 // goto fail;
264 // }
265 }
266
267 if (fdt_addr) {
268 efi_info("Using DTB from command line\n");
269 } else {
270 /* Look for a device tree configuration table entry. */
271 fdt_addr = (uintptr_t)get_fdt(&fdt_size);
272 if (fdt_addr)
273 efi_info("Using DTB from configuration table\n");
274 }
275
276 if (!fdt_addr)
277 efi_info("Generating empty DTB\n");
278
279 status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
280 if (status != EFI_SUCCESS) {
281 efi_err("Unable to allocate memory for new device tree.\n");
282 goto fail;
283 }
284 efi_debug("New FDT address: 0x%lx\n", *new_fdt_addr);
285 efi_info("Generating new FDT...\n");
286 status = update_fdt((void *)fdt_addr, fdt_size, (void *)*new_fdt_addr,
287 MAX_FDT_SIZE, cmdline_ptr);
288
289 if (status != EFI_SUCCESS) {
290 efi_err("Unable to construct new device tree.\n");
291 goto fail_free_new_fdt;
292 }
293
294 priv.new_fdt_addr = (void *)*new_fdt_addr;
295
296 efi_info("Exiting boot services...\n");
297 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
298
299 if (status == EFI_SUCCESS) {
300 efi_set_virtual_address_map_t *svam;
301
302 if (efi_novamap)
303 return EFI_SUCCESS;
304
305 /* Install the new virtual address map */
306 svam = ST->RuntimeServices->SetVirtualAddressMap;
307 status = svam(priv.runtime_entry_count * desc_size, desc_size,
308 desc_ver, priv.runtime_map);
309 /*
310 * We are beyond the point of no return here, so if the call to
311 * SetVirtualAddressMap() failed, we need to signal that to the
312 * incoming kernel but proceed normally otherwise.
313 */
314 if (status != EFI_SUCCESS) {
315 efi_memory_desc_t *p;
316 int l;
317
318 /*
319 * Set the virtual address field of all
320 * EFI_MEMORY_RUNTIME entries to U64_MAX. This will
321 * signal the incoming kernel that no virtual
322 * translation has been installed.
323 */
324 for (l = 0; l < priv.boot_memmap->map_size;
325 l += priv.boot_memmap->desc_size) {
326 p = (void *)priv.boot_memmap->map + l;
327
328 if (p->Attribute & EFI_MEMORY_RUNTIME)
329 p->VirtualStart = UINT64_MAX;
330 }
331 }
332 return EFI_SUCCESS;
333 }
334
335 efi_err("Exit boot services failed.\n");
336
337 fail_free_new_fdt:
338 efi_free(MAX_FDT_SIZE, *new_fdt_addr);
339
340 fail:
341 efi_free(fdt_size, fdt_addr);
342
343 efi_bs_call(FreePool, priv.runtime_map);
344
345 return EFI_LOAD_ERROR;
346 }
347
efi_boot_kernel(efi_handle_t handle,efi_loaded_image_t * loaded_image,struct payload_info * payload_info,char * cmdline_ptr)348 efi_status_t efi_boot_kernel(efi_handle_t handle,
349 efi_loaded_image_t *loaded_image,
350 struct payload_info *payload_info,
351 char *cmdline_ptr)
352 {
353 unsigned long fdt_addr;
354 efi_status_t status;
355
356 efi_info("Loading ELF payload...\n");
357 // 加载ELF
358 status = load_elf(payload_info);
359
360 if (status != EFI_SUCCESS) {
361 efi_err("Failed to load ELF payload, efi error code: %d\n",
362 status);
363 return status;
364 }
365
366 efi_debug("kernel entry point: 0x%lx\n", payload_info->kernel_entry);
367 status = allocate_new_fdt_and_exit_boot(handle, loaded_image, &fdt_addr,
368 cmdline_ptr);
369 if (status != EFI_SUCCESS) {
370 efi_err("Failed to update FDT and exit boot services\n");
371 return status;
372 }
373 #ifdef CONFIG_ARM
374 efi_handle_post_ebs_state();
375 #endif
376
377 efi_enter_kernel(payload_info, fdt_addr,
378 fdt_totalsize((void *)fdt_addr));
379 /* not reached */
380 }
381
get_fdt(unsigned long * fdt_size)382 void *get_fdt(unsigned long *fdt_size)
383 {
384 void *fdt;
385
386 fdt = get_efi_config_table(DEVICE_TREE_GUID);
387
388 if (!fdt)
389 return NULL;
390
391 if (fdt_check_header(fdt) != 0) {
392 efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n");
393 return NULL;
394 }
395 *fdt_size = fdt_totalsize(fdt);
396 return fdt;
397 }
398