1 #include "dragonstub/printk.h"
2 #include "efidef.h"
3 #include <efi.h>
4 #include <efilib.h>
5 #include <elf.h>
6 #include <dragonstub/dragonstub.h>
7 #include <dragonstub/elfloader.h>
8 #include <dragonstub/linux/math.h>
9 #include <dragonstub/linux/align.h>
10
11 /*
12 * This is the base address at which to start allocating virtual memory ranges
13 * for UEFI Runtime Services.
14 *
15 * For ARM/ARM64:
16 * This is in the low TTBR0 range so that we can use
17 * any allocation we choose, and eliminate the risk of a conflict after kexec.
18 * The value chosen is the largest non-zero power of 2 suitable for this purpose
19 * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
20 * be mapped efficiently.
21 * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
22 * map everything below 1 GB. (512 MB is a reasonable upper bound for the
23 * entire footprint of the UEFI runtime services memory regions)
24 *
25 * For RISC-V:
26 * There is no specific reason for which, this address (512MB) can't be used
27 * EFI runtime virtual address for RISC-V. It also helps to use EFI runtime
28 * services on both RV32/RV64. Keep the same runtime virtual address for RISC-V
29 * as well to minimize the code churn.
30 */
31 #define EFI_RT_VIRTUAL_BASE SZ_512M
32
33 /*
34 * Some architectures map the EFI regions into the kernel's linear map using a
35 * fixed offset.
36 */
37 #ifndef EFI_RT_VIRTUAL_OFFSET
38 #define EFI_RT_VIRTUAL_OFFSET 0
39 #endif
40
41 extern void _image_end(void);
42
43 static u64 image_base = 0;
44 static u64 image_size = 0;
45 static u64 image_end = 0;
46
47 static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
48 static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
49
efi_handle_cmdline(EFI_LOADED_IMAGE * image,char ** cmdline_ptr)50 EFI_STATUS efi_handle_cmdline(EFI_LOADED_IMAGE *image, char **cmdline_ptr)
51 {
52 int cmdline_size = 0;
53 EFI_STATUS status;
54 char *cmdline;
55
56 /*
57 * Get the command line from EFI, using the LOADED_IMAGE
58 * protocol. We are going to copy the command line into the
59 * device tree, so this can be allocated anywhere.
60 */
61 cmdline = efi_convert_cmdline(image, &cmdline_size);
62 if (!cmdline) {
63 efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
64 return EFI_OUT_OF_RESOURCES;
65 }
66
67 // if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
68 // IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
69 // cmdline_size == 0) {
70 // status = efi_parse_options(CONFIG_CMDLINE);
71 // if (status != EFI_SUCCESS) {
72 // efi_err("Failed to parse options\n");
73 // goto fail_free_cmdline;
74 // }
75 // }
76
77 // if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
78 if (cmdline_size > 0) {
79 status = efi_parse_options(cmdline);
80 if (status != EFI_SUCCESS) {
81 efi_err("Failed to parse options\n");
82 goto fail_free_cmdline;
83 }
84 }
85
86 *cmdline_ptr = cmdline;
87 return EFI_SUCCESS;
88
89 fail_free_cmdline:
90 efi_bs_call(FreePool, cmdline_ptr);
91 return status;
92 }
93
init_efi_program_info(efi_loaded_image_t * loaded_image)94 static efi_status_t init_efi_program_info(efi_loaded_image_t *loaded_image)
95 {
96 image_base = (u64)loaded_image->ImageBase;
97 image_size = loaded_image->ImageSize;
98 image_end = (u64)_image_end;
99 efi_info("DragonStub loaded at 0x%p\n", image_base);
100 efi_info("DragonStub + payload size: 0x%p\n", image_size);
101 efi_info("DragonStub end addr: 0x%p\n", image_end);
102 return EFI_SUCCESS;
103 }
104
105 /// @brief payload_info的构造函数
payload_info_new(u64 payload_addr,u64 payload_size)106 static struct payload_info payload_info_new(u64 payload_addr, u64 payload_size)
107 {
108 struct payload_info info = { .payload_addr = payload_addr,
109 .payload_size = payload_size,
110 .loaded_paddr = 0,
111 .loaded_size = 0,
112 .kernel_entry = 0 };
113 return info;
114 }
find_elf(struct payload_info * info)115 static efi_status_t find_elf(struct payload_info *info)
116 {
117 extern __weak void _binary_payload_start(void);
118 extern __weak void _binary_payload_end(void);
119 extern __weak void _binary_payload_size(void);
120 u64 payload_start = (u64)_binary_payload_start;
121 u64 payload_end = (u64)_binary_payload_end;
122
123 u64 payload_size = payload_end - payload_start;
124
125 efi_info("payload_addr: %p\n", payload_start);
126 efi_info("payload_end: %p\n", payload_end);
127 efi_info("payload_size: %p\n", payload_size);
128
129 if (payload_start == 0 || payload_end <= payload_start + 4 ||
130 payload_size == 0) {
131 return EFI_NOT_FOUND;
132 }
133
134 efi_info("Checking payload's ELF header...\n");
135 bool found = elf_check((void *)payload_start, payload_size);
136
137 if (found) {
138 info->payload_addr = payload_start;
139 info->payload_size = payload_size;
140 efi_info("Found payload ELF header\n");
141 return EFI_SUCCESS;
142 }
143
144 return EFI_NOT_FOUND;
145 }
146
147 /// @brief 寻找要加载的内核负载
148 /// @param handle efi_handle
149 /// @param image efi_loaded_image_t
150 /// @param ret_info 返回的负载信息
151 /// @return
find_payload(efi_handle_t handle,efi_loaded_image_t * loaded_image,struct payload_info * ret_info)152 efi_status_t find_payload(efi_handle_t handle, efi_loaded_image_t *loaded_image,
153 struct payload_info *ret_info)
154 {
155 efi_info("Try to find payload to boot\n");
156 efi_status_t status = init_efi_program_info(loaded_image);
157 if (status != EFI_SUCCESS) {
158 efi_err("Failed to init efi program info\n");
159 return status;
160 }
161
162 struct payload_info info = payload_info_new(0, 0);
163
164 status = find_elf(&info);
165 if (status != EFI_SUCCESS) {
166 efi_err("Payload not found: Did you forget to add the payload by setting PAYLOAD_ELF at compile time?\n"
167 "Or the payload is not an ELF file?\n");
168 return status;
169 }
170
171 *ret_info = info;
172 return EFI_SUCCESS;
173 }
174
175 /*
176 * efi_allocate_virtmap() - create a pool allocation for the virtmap
177 *
178 * Create an allocation that is of sufficient size to hold all the memory
179 * descriptors that will be passed to SetVirtualAddressMap() to inform the
180 * firmware about the virtual mapping that will be used under the OS to call
181 * into the firmware.
182 */
efi_alloc_virtmap(efi_memory_desc_t ** virtmap,unsigned long * desc_size,u32 * desc_ver)183 efi_status_t efi_alloc_virtmap(efi_memory_desc_t **virtmap,
184 unsigned long *desc_size, u32 *desc_ver)
185 {
186 unsigned long size, mmap_key;
187 efi_status_t status;
188
189 /*
190 * Use the size of the current memory map as an upper bound for the
191 * size of the buffer we need to pass to SetVirtualAddressMap() to
192 * cover all EFI_MEMORY_RUNTIME regions.
193 */
194 size = 0;
195 status = efi_bs_call(GetMemoryMap, &size, NULL, &mmap_key, desc_size,
196 desc_ver);
197 if (status != EFI_BUFFER_TOO_SMALL)
198 return EFI_LOAD_ERROR;
199
200 return efi_bs_call(AllocatePool, EfiLoaderData, size, (void **)virtmap);
201 }
202
203 /*
204 * efi_get_virtmap() - create a virtual mapping for the EFI memory map
205 *
206 * This function populates the virt_addr fields of all memory region descriptors
207 * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
208 * are also copied to @runtime_map, and their total count is returned in @count.
209 */
efi_get_virtmap(efi_memory_desc_t * memory_map,unsigned long map_size,unsigned long desc_size,efi_memory_desc_t * runtime_map,int * count)210 void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
211 unsigned long desc_size, efi_memory_desc_t *runtime_map,
212 int *count)
213 {
214 u64 efi_virt_base = virtmap_base;
215 efi_memory_desc_t *in, *out = runtime_map;
216 int l;
217
218 *count = 0;
219
220 for (l = 0; l < map_size; l += desc_size) {
221 u64 paddr, size;
222
223 in = (void *)memory_map + l;
224 if (!(in->Attribute & EFI_MEMORY_RUNTIME))
225 continue;
226
227 paddr = in->PhysicalStart;
228 size = in->NumberOfPages * EFI_PAGE_SIZE;
229
230 in->VirtualStart = in->PhysicalStart + EFI_RT_VIRTUAL_OFFSET;
231 if (efi_novamap) {
232 continue;
233 }
234
235 /*
236 * Make the mapping compatible with 64k pages: this allows
237 * a 4k page size kernel to kexec a 64k page size kernel and
238 * vice versa.
239 */
240 if (!flat_va_mapping) {
241 paddr = round_down(in->PhysicalStart, SZ_64K);
242 size += in->PhysicalStart - paddr;
243
244 /*
245 * Avoid wasting memory on PTEs by choosing a virtual
246 * base that is compatible with section mappings if this
247 * region has the appropriate size and physical
248 * alignment. (Sections are 2 MB on 4k granule kernels)
249 */
250 if (IS_ALIGNED(in->PhysicalStart, SZ_2M) &&
251 size >= SZ_2M)
252 efi_virt_base = round_up(efi_virt_base, SZ_2M);
253 else
254 efi_virt_base = round_up(efi_virt_base, SZ_64K);
255
256 in->VirtualStart += efi_virt_base - paddr;
257 efi_virt_base += size;
258 }
259
260 memcpy(out, in, desc_size);
261 out = (void *)out + desc_size;
262 ++*count;
263 }
264 }
265
266 /// @brief 设置内存保留表
267 /// @param
install_memreserve_table(void)268 static void install_memreserve_table(void)
269 {
270 struct linux_efi_memreserve *rsv;
271 efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
272 efi_status_t status;
273
274 status = efi_bs_call(AllocatePool, EfiLoaderData, sizeof(*rsv),
275 (void **)&rsv);
276 if (status != EFI_SUCCESS) {
277 efi_err("Failed to allocate memreserve entry!\n");
278 return;
279 }
280
281 rsv->next = 0;
282 rsv->size = 0;
283 rsv->count = 0;
284
285 status = efi_bs_call(InstallConfigurationTable, &memreserve_table_guid,
286 rsv);
287 if (status != EFI_SUCCESS)
288 efi_err("Failed to install memreserve config table!\n");
289 }
290
get_supported_rt_services(void)291 static u32 get_supported_rt_services(void)
292 {
293 const efi_rt_properties_table_t *rt_prop_table;
294 u32 supported = EFI_RT_SUPPORTED_ALL;
295
296 rt_prop_table = get_efi_config_table(EFI_RT_PROPERTIES_TABLE_GUID);
297 if (rt_prop_table)
298 supported &= rt_prop_table->runtime_services_supported;
299
300 return supported;
301 }
302
efi_stub_common(efi_handle_t handle,efi_loaded_image_t * loaded_image,struct payload_info * payload_info,char * cmdline_ptr)303 efi_status_t efi_stub_common(efi_handle_t handle,
304 efi_loaded_image_t *loaded_image,
305 struct payload_info *payload_info,
306 char *cmdline_ptr)
307 {
308 struct screen_info *si;
309 efi_status_t status;
310
311 status = check_platform_features();
312 if (status != EFI_SUCCESS)
313 return status;
314
315 // si = setup_graphics();
316
317 // efi_retrieve_tpm2_eventlog();
318
319 // /* Ask the firmware to clear memory on unclean shutdown */
320 // efi_enable_reset_attack_mitigation();
321
322 // efi_load_initrd(image, ULONG_MAX, efi_get_max_initrd_addr(image_addr),
323 // NULL);
324
325 // efi_random_get_seed();
326
327 /* force efi_novamap if SetVirtualAddressMap() is unsupported */
328 efi_novamap |= !(get_supported_rt_services() &
329 EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP);
330
331 install_memreserve_table();
332 efi_info("Memreserve table installed\n");
333 efi_info("Booting DragonOS kernel...\n");
334 status = efi_boot_kernel(handle, loaded_image, payload_info,
335 cmdline_ptr);
336
337 // free_screen_info(si);
338 return status;
339 }
340