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 };
 130
 131 static bool efi_runtime_tobedetached(void *p)
 132 {
 133         int i;
 134
 135         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
 136                 if (efi_runtime_detach_list[i].ptr == p)
 137                         return true;
 138
 139         return false;
 140 }
 141
 142 static void efi_runtime_detach(ulong offset)
 143 {
 144         int i;
 145         ulong patchoff = offset - (ulong)gd->relocaddr;
 146
 147         for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
 148                 ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
 149                 ulong *p = efi_runtime_detach_list[i].ptr;
 150                 ulong newaddr = patchto ? (patchto + patchoff) : 0;
 151
 152 #ifdef DEBUG_EFI
 153                 printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
 154 #endif
 155                 *p = newaddr;
 156         }
 157 }
 158
 159 /* Relocate EFI runtime to uboot_reloc_base = offset */
 160 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
 161 {
 162 #ifdef IS_RELA
 163         struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
 164 #else
 165         struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
 166         static ulong lastoff = CONFIG_SYS_TEXT_BASE;
 167 #endif
 168
 169 #ifdef DEBUG_EFI
 170         printf("%s: Relocating to offset=%lx\n", __func__, offset);
 171 #endif
 172
 173         for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
 174                 ulong base = CONFIG_SYS_TEXT_BASE;
 175                 ulong *p;
 176                 ulong newaddr;
 177
 178                 p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
 179
 180                 if ((rel->info & R_MASK) != R_RELATIVE) {
 181                         continue;
 182                 }
 183
 184 #ifdef IS_RELA
 185                 newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
 186 #else
 187                 newaddr = *p - lastoff + offset;
 188 #endif
 189
 190                 /* Check if the relocation is inside bounds */
 191                 if (map && ((newaddr < map->virtual_start) ||
 192                     newaddr > (map->virtual_start + (map->num_pages << 12)))) {
 193                         if (!efi_runtime_tobedetached(p))
 194                                 printf("U-Boot EFI: Relocation at %p is out of "
 195                                        "range (%lx)\n", p, newaddr);
 196                         continue;
 197                 }
 198
 199 #ifdef DEBUG_EFI
 200                 printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
 201 #endif
 202
 203                 *p = newaddr;
 204                 flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
 205                         ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
 206         }
 207
 208 #ifndef IS_RELA
 209         lastoff = offset;
 210 #endif
 211
 212         invalidate_icache_all();
 213 }
 214
 215 static efi_status_t EFIAPI efi_set_virtual_address_map(
 216                         unsigned long memory_map_size,
 217                         unsigned long descriptor_size,
 218                         uint32_t descriptor_version,
 219                         struct efi_mem_desc *virtmap)
 220 {
 221         ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
 222         int n = memory_map_size / descriptor_size;
 223         int i;
 224
 225         EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
 226                   descriptor_version, virtmap);
 227
 228         for (i = 0; i < n; i++) {
 229                 struct efi_mem_desc *map;
 230
 231                 map = (void*)virtmap + (descriptor_size * i);
 232                 if (map->type == EFI_RUNTIME_SERVICES_CODE) {
 233                         ulong new_offset = map->virtual_start - (runtime_start - gd->relocaddr);
 234
 235                         efi_runtime_relocate(new_offset, map);
 236                         /* Once we're virtual, we can no longer handle
 237                            complex callbacks */
 238                         efi_runtime_detach(new_offset);
 239                         return EFI_EXIT(EFI_SUCCESS);
 240                 }
 241         }
 242
 243         return EFI_EXIT(EFI_INVALID_PARAMETER);
 244 }
 245
 246 /*
 247  * In the second stage, U-Boot has disappeared. To isolate our runtime code
 248  * that at this point still exists from the rest, we put it into a special
 249  * section.
 250  *
 251  *        !!WARNING!!
 252  *
 253  * This means that we can not rely on any code outside of this file in any
 254  * function or variable below this line.
 255  *
 256  * Please keep everything fully self-contained and annotated with
 257  * EFI_RUNTIME_TEXT and EFI_RUNTIME_DATA markers.
 258  */
 259
 260 /*
 261  * Relocate the EFI runtime stub to a different place. We need to call this
 262  * the first time we expose the runtime interface to a user and on set virtual
 263  * address map calls.
 264  */
 265
 266 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void)
 267 {
 268         return EFI_UNSUPPORTED;
 269 }
 270
 271 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void)
 272 {
 273         return EFI_DEVICE_ERROR;
 274 }
 275
 276 static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void)
 277 {
 278         return EFI_INVALID_PARAMETER;
 279 }
 280
 281 struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = {
 282         .hdr = {
 283                 .signature = EFI_RUNTIME_SERVICES_SIGNATURE,
 284                 .revision = EFI_RUNTIME_SERVICES_REVISION,
 285                 .headersize = sizeof(struct efi_table_hdr),
 286         },
 287         .get_time = &efi_get_time,
 288         .set_time = (void *)&efi_device_error,
 289         .get_wakeup_time = (void *)&efi_unimplemented,
 290         .set_wakeup_time = (void *)&efi_unimplemented,
 291         .set_virtual_address_map = &efi_set_virtual_address_map,
 292         .convert_pointer = (void *)&efi_invalid_parameter,
 293         .get_variable = (void *)&efi_device_error,
 294         .get_next_variable = (void *)&efi_device_error,
 295         .set_variable = (void *)&efi_device_error,
 296         .get_next_high_mono_count = (void *)&efi_device_error,
 297         .reset_system = &efi_reset_system,
 298 };