lib/efi_loader/efi_runtime.c

   1 /*
   2  *  EFI application runtime services
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <command.h>
  11 #include <dm.h>
  12 #include <efi_loader.h>
  13 #include <rtc.h>
  14 #include <asm/global_data.h>
  15
  16 /* For manual relocation support */
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void);
  20 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void);
  21 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void);
  22
  23 #ifdef CONFIG_SYS_CACHELINE_SIZE
  24 #define EFI_CACHELINE_SIZE CONFIG_SYS_CACHELINE_SIZE
  25 #else
  26 /* Just use the greatest cache flush alignment requirement I'm aware of */
  27 #define EFI_CACHELINE_SIZE 128
  28 #endif
  29
  30 #if defined(CONFIG_ARM64)
  31 #define R_RELATIVE      1027
  32 #define R_MASK          0xffffffffULL
  33 #define IS_RELA         1
  34 #elif defined(CONFIG_ARM)
  35 #define R_RELATIVE      23
  36 #define R_MASK          0xffULL
  37 #else
  38 #error Need to add relocation awareness
  39 #endif
  40
  41 struct elf_rel {
  42         ulong *offset;
  43         ulong info;
  44 };
  45
  46 struct elf_rela {
  47         ulong *offset;
  48         ulong info;
  49         long addend;
  50 };
  51
  52 /*
  53  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
  54  * payload are running concurrently at the same time. In this mode, we can
  55  * handle a good number of runtime callbacks
  56  */
  57
  58 static void EFIAPI efi_reset_system(enum efi_reset_type reset_type,
  59                                     efi_status_t reset_status,
  60                                     unsigned long data_size, void *reset_data)
  61 {
  62         EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
  63                   reset_data);
  64
  65         switch (reset_type) {
  66         case EFI_RESET_COLD:
  67         case EFI_RESET_WARM:
  68                 do_reset(NULL, 0, 0, NULL);
  69                 break;
  70         case EFI_RESET_SHUTDOWN:
  71                 /* We don't have anything to map this to */
  72                 break;
  73         }
  74
  75         EFI_EXIT(EFI_SUCCESS);
  76 }
  77
  78 static efi_status_t EFIAPI efi_get_time(struct efi_time *time,
  79                                         struct efi_time_cap *capabilities)
  80 {
  81 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
  82         struct rtc_time tm;
  83         int r;
  84         struct udevice *dev;
  85
  86         EFI_ENTRY("%p %p", time, capabilities);
  87
  88         r = uclass_get_device(UCLASS_RTC, 0, &dev);
  89         if (r)
  90                 return EFI_EXIT(EFI_DEVICE_ERROR);
  91
  92         r = dm_rtc_get(dev, &tm);
  93         if (r)
  94                 return EFI_EXIT(EFI_DEVICE_ERROR);
  95
  96         memset(time, 0, sizeof(*time));
  97         time->year = tm.tm_year;
  98         time->month = tm.tm_mon;
  99         time->day = tm.tm_mday;
 100         time->hour = tm.tm_hour;
 101         time->minute = tm.tm_min;
 102         time->daylight = tm.tm_isdst;
 103
 104         return EFI_EXIT(EFI_SUCCESS);
 105 #else
 106         return EFI_DEVICE_ERROR;
 107 #endif
 108 }
 109
 110 struct efi_runtime_detach_list_struct {
 111         void *ptr;
 112         void *patchto;
 113 };
 114
 115 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
 116         {
 117                 /* do_reset is gone */
 118                 .ptr = &efi_runtime_services.reset_system,
 119                 .patchto = NULL,
 120         }, {
 121                 /* invalidate_*cache_all are gone */
 122                 .ptr = &efi_runtime_services.set_virtual_address_map,
 123                 .patchto = &efi_invalid_parameter,
 124         }, {
 125                 /* RTC accessors are gone */
 126                 .ptr = &efi_runtime_services.get_time,
 127                 .patchto = &efi_device_error,
 128         }, {
 129                 /* Clean up system table */
 130                 .ptr = &systab.con_in,
 131                 .patchto = NULL,
 132         }, {
 133                 /* Clean up system table */
 134                 .ptr = &systab.con_out,
 135                 .patchto = NULL,
 136         }, {
 137                 /* Clean up system table */
 138                 .ptr = &systab.std_err,
 139                 .patchto = NULL,
 140         }, {
 141                 /* Clean up system table */
 142                 .ptr = &systab.boottime,
 143                 .patchto = NULL,
 144         },
 145 };
 146
 147 static bool efi_runtime_tobedetached(void *p)
 148 {
 149         int i;
 150
 151         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
 152                 if (efi_runtime_detach_list[i].ptr == p)
 153                         return true;
 154
 155         return false;
 156 }
 157
 158 static void efi_runtime_detach(ulong offset)
 159 {
 160         int i;
 161         ulong patchoff = offset - (ulong)gd->relocaddr;
 162
 163         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
 164                 ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
 165                 ulong *p = efi_runtime_detach_list[i].ptr;
 166                 ulong newaddr = patchto ? (patchto + patchoff) : 0;
 167
 168 #ifdef DEBUG_EFI
 169                 printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
 170 #endif
 171                 *p = newaddr;
 172         }
 173 }
 174
 175 /* Relocate EFI runtime to uboot_reloc_base = offset */
 176 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
 177 {
 178 #ifdef IS_RELA
 179         struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
 180 #else
 181         struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
 182         static ulong lastoff = CONFIG_SYS_TEXT_BASE;
 183 #endif
 184
 185 #ifdef DEBUG_EFI
 186         printf("%s: Relocating to offset=%lx\n", __func__, offset);
 187 #endif
 188
 189         for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
 190                 ulong base = CONFIG_SYS_TEXT_BASE;
 191                 ulong *p;
 192                 ulong newaddr;
 193
 194                 p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
 195
 196                 if ((rel->info & R_MASK) != R_RELATIVE) {
 197                         continue;
 198                 }
 199
 200 #ifdef IS_RELA
 201                 newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
 202 #else
 203                 newaddr = *p - lastoff + offset;
 204 #endif
 205
 206                 /* Check if the relocation is inside bounds */
 207                 if (map && ((newaddr < map->virtual_start) ||
 208                     newaddr > (map->virtual_start + (map->num_pages << 12)))) {
 209                         if (!efi_runtime_tobedetached(p))
 210                                 printf("U-Boot EFI: Relocation at %p is out of "
 211                                        "range (%lx)\n", p, newaddr);
 212                         continue;
 213                 }
 214
 215 #ifdef DEBUG_EFI
 216                 printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
 217 #endif
 218
 219                 *p = newaddr;
 220                 flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
 221                         ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
 222         }
 223
 224 #ifndef IS_RELA
 225         lastoff = offset;
 226 #endif
 227
 228         invalidate_icache_all();
 229 }
 230
 231 static efi_status_t EFIAPI efi_set_virtual_address_map(
 232                         unsigned long memory_map_size,
 233                         unsigned long descriptor_size,
 234                         uint32_t descriptor_version,
 235                         struct efi_mem_desc *virtmap)
 236 {
 237         ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
 238         int n = memory_map_size / descriptor_size;
 239         int i;
 240
 241         EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
 242                   descriptor_version, virtmap);
 243
 244         for (i = 0; i < n; i++) {
 245                 struct efi_mem_desc *map;
 246
 247                 map = (void*)virtmap + (descriptor_size * i);
 248                 if (map->type == EFI_RUNTIME_SERVICES_CODE) {
 249                         ulong new_offset = map->virtual_start - (runtime_start - gd->relocaddr);
 250
 251                         efi_runtime_relocate(new_offset, map);
 252                         /* Once we're virtual, we can no longer handle
 253                            complex callbacks */
 254                         efi_runtime_detach(new_offset);
 255                         return EFI_EXIT(EFI_SUCCESS);
 256                 }
 257         }
 258
 259         return EFI_EXIT(EFI_INVALID_PARAMETER);
 260 }
 261
 262 /*
 263  * In the second stage, U-Boot has disappeared. To isolate our runtime code
 264  * that at this point still exists from the rest, we put it into a special
 265  * section.
 266  *
 267  *        !!WARNING!!
 268  *
 269  * This means that we can not rely on any code outside of this file in any
 270  * function or variable below this line.
 271  *
 272  * Please keep everything fully self-contained and annotated with
 273  * EFI_RUNTIME_TEXT and EFI_RUNTIME_DATA markers.
 274  */
 275
 276 /*
 277  * Relocate the EFI runtime stub to a different place. We need to call this
 278  * the first time we expose the runtime interface to a user and on set virtual
 279  * address map calls.
 280  */
 281
 282 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void)
 283 {
 284         return EFI_UNSUPPORTED;
 285 }
 286
 287 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void)
 288 {
 289         return EFI_DEVICE_ERROR;
 290 }
 291
 292 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void)
 293 {
 294         return EFI_INVALID_PARAMETER;
 295 }
 296
 297 struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = {
 298         .hdr = {
 299                 .signature = EFI_RUNTIME_SERVICES_SIGNATURE,
 300                 .revision = EFI_RUNTIME_SERVICES_REVISION,
 301                 .headersize = sizeof(struct efi_table_hdr),
 302         },
 303         .get_time = &efi_get_time,
 304         .set_time = (void *)&efi_device_error,
 305         .get_wakeup_time = (void *)&efi_unimplemented,
 306         .set_wakeup_time = (void *)&efi_unimplemented,
 307         .set_virtual_address_map = &efi_set_virtual_address_map,
 308         .convert_pointer = (void *)&efi_invalid_parameter,
 309         .get_variable = (void *)&efi_device_error,
 310         .get_next_variable = (void *)&efi_device_error,
 311         .set_variable = (void *)&efi_device_error,
 312         .get_next_high_mono_count = (void *)&efi_device_error,
 313         .reset_system = &efi_reset_system,
 314 };