/src/u-boot/lib/efi_loader/efi_runtime.c

Source
// SPDX-License-Identifier: GPL-2.0+
/*
 *  EFI application runtime services
 *
 *  Copyright (c) 2016 Alexander Graf
 */

#define LOG_CATEGORY LOGC_EFI

#include <command.h>
#include <cpu_func.h>
#include <dm.h>
#include <elf.h>
#include <efi_loader.h>
#include <efi_variable.h>
#include <log.h>
#include <malloc.h>
#include <rtc.h>
#include <asm/global_data.h>
#include <u-boot/crc.h>
#include <asm/sections.h>

/* For manual relocation support */
DECLARE_GLOBAL_DATA_PTR;

/* GUID of the runtime properties table */
static const efi_guid_t efi_rt_properties_table_guid =
        EFI_RT_PROPERTIES_TABLE_GUID;

struct efi_runtime_mmio_list {
  struct list_head link;
  void **ptr;
  u64 paddr;
  u64 len;
};

/* This list contains all runtime available mmio regions */
static LIST_HEAD(efi_runtime_mmio);

static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);

/*
 * TODO(sjg@chromium.org): These defines and structures should come from the ELF
 * header for each architecture (or a generic header) rather than being repeated
 * here.
 */
#if defined(__aarch64__)
#define R_RELATIVE  R_AARCH64_RELATIVE
#define R_MASK    0xffffffffULL
#define IS_RELA   1
#elif defined(__arm__)
#define R_RELATIVE  R_ARM_RELATIVE
#define R_MASK    0xffULL
#elif defined(__i386__)
#define R_RELATIVE  R_386_RELATIVE
#define R_MASK    0xffULL
#elif defined(__x86_64__)
#define R_RELATIVE  R_X86_64_RELATIVE
#define R_MASK    0xffffffffULL
#define IS_RELA   1
#elif defined(__riscv)
#define R_RELATIVE  R_RISCV_RELATIVE
#define R_MASK    0xffULL
#define IS_RELA   1

struct dyn_sym {
  ulong foo1;
  ulong addr;
  u32 foo2;
  u32 foo3;
};
#if (__riscv_xlen == 32)
#define R_ABSOLUTE  R_RISCV_32
#define SYM_INDEX 8
#elif (__riscv_xlen == 64)
#define R_ABSOLUTE  R_RISCV_64
#define SYM_INDEX 32
#else
#error unknown riscv target
#endif
#else
#error Need to add relocation awareness
#endif

struct elf_rel {
  ulong *offset;
  ulong info;
};

struct elf_rela {
  ulong *offset;
  ulong info;
  long addend;
};

static __efi_runtime_data struct efi_mem_desc *efi_virtmap;
static __efi_runtime_data efi_uintn_t efi_descriptor_count;
static __efi_runtime_data efi_uintn_t efi_descriptor_size;

/*
 * EFI runtime code lives in two stages. In the first stage, U-Boot and an EFI
 * payload are running concurrently at the same time. In this mode, we can
 * handle a good number of runtime callbacks
 */

/**
 * efi_init_runtime_supported() - create runtime properties table
 *
 * Create a configuration table specifying which services are available at
 * runtime.
 *
 * Return:  status code
 */
efi_status_t efi_init_runtime_supported(void)
{
  const efi_guid_t efi_guid_efi_rt_var_file = U_BOOT_EFI_RT_VAR_FILE_GUID;
  efi_status_t ret;
  struct efi_rt_properties_table *rt_table;

  ret = efi_allocate_pool(EFI_RUNTIME_SERVICES_DATA,
        sizeof(struct efi_rt_properties_table),
        (void **)&rt_table);
  if (ret != EFI_SUCCESS)
    return ret;

  rt_table->version = EFI_RT_PROPERTIES_TABLE_VERSION;
  rt_table->length = sizeof(struct efi_rt_properties_table);
  rt_table->runtime_services_supported =
        EFI_RT_SUPPORTED_GET_VARIABLE |
        EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME |
        EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP |
        EFI_RT_SUPPORTED_CONVERT_POINTER;

  if (IS_ENABLED(CONFIG_EFI_VARIABLE_FILE_STORE))
    rt_table->runtime_services_supported |=
      EFI_RT_SUPPORTED_QUERY_VARIABLE_INFO;

  if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
    u8 s = 0;

    ret = efi_set_variable_int(u"RTStorageVolatile",
             &efi_guid_efi_rt_var_file,
             EFI_VARIABLE_BOOTSERVICE_ACCESS |
             EFI_VARIABLE_RUNTIME_ACCESS |
             EFI_VARIABLE_READ_ONLY,
             sizeof(EFI_VAR_FILE_NAME),
             EFI_VAR_FILE_NAME, false);
    if (ret != EFI_SUCCESS) {
      log_err("Failed to set RTStorageVolatile\n");
      return ret;
    }
    /*
     * This variable needs to be visible so users can read it,
     * but the real contents are going to be filled during
     * GetVariable
     */
    ret = efi_set_variable_int(u"VarToFile",
             &efi_guid_efi_rt_var_file,
             EFI_VARIABLE_BOOTSERVICE_ACCESS |
             EFI_VARIABLE_RUNTIME_ACCESS |
             EFI_VARIABLE_READ_ONLY,
             sizeof(s),
             &s, false);
    if (ret != EFI_SUCCESS) {
      log_err("Failed to set VarToFile\n");
      efi_set_variable_int(u"RTStorageVolatile",
               &efi_guid_efi_rt_var_file,
               EFI_VARIABLE_BOOTSERVICE_ACCESS |
               EFI_VARIABLE_RUNTIME_ACCESS |
               EFI_VARIABLE_READ_ONLY,
               0, NULL, false);

      return ret;
    }
    rt_table->runtime_services_supported |= EFI_RT_SUPPORTED_SET_VARIABLE;
  }

  /*
   * This value must be synced with efi_runtime_detach_list
   * as well as efi_runtime_services.
   */
#ifdef CONFIG_EFI_HAVE_RUNTIME_RESET
  rt_table->runtime_services_supported |= EFI_RT_SUPPORTED_RESET_SYSTEM;
#endif

  ret = efi_install_configuration_table(&efi_rt_properties_table_guid,
                rt_table);
  return ret;
}

/**
 * efi_memcpy_runtime() - copy memory area
 *
 * At runtime memcpy() is not available.
 *
 * Overlapping memory areas can be copied safely if src >= dest.
 *
 * @dest: destination buffer
 * @src:  source buffer
 * @n:    number of bytes to copy
 * Return:  pointer to destination buffer
 */
void __efi_runtime efi_memcpy_runtime(void *dest, const void *src, size_t n)
{
  u8 *d = dest;
  const u8 *s = src;

  for (; n; --n)
    *d++ = *s++;
}

/**
 * efi_update_table_header_crc32() - Update crc32 in table header
 *
 * @table:  EFI table
 */
void __efi_runtime efi_update_table_header_crc32(struct efi_table_hdr *table)
{
  table->crc32 = 0;
  table->crc32 = crc32(0, (const unsigned char *)table,
           table->headersize);
}

/**
 * efi_reset_system_boottime() - reset system at boot time
 *
 * This function implements the ResetSystem() runtime service before
 * SetVirtualAddressMap() is called.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @reset_type:   type of reset to perform
 * @reset_status: status code for the reset
 * @data_size:    size of reset_data
 * @reset_data:   information about the reset
 */
static void EFIAPI efi_reset_system_boottime(
      enum efi_reset_type reset_type,
      efi_status_t reset_status,
      unsigned long data_size, void *reset_data)
{
  struct efi_event *evt;

  EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
      reset_data);

  /* Notify reset */
  list_for_each_entry(evt, &efi_events, link) {
    if (evt->group &&
        !guidcmp(evt->group,
           &efi_guid_event_group_reset_system)) {
      efi_signal_event(evt);
      break;
    }
  }
  switch (reset_type) {
  case EFI_RESET_COLD:
  case EFI_RESET_WARM:
  case EFI_RESET_PLATFORM_SPECIFIC:
    do_reset(NULL, 0, 0, NULL);
    break;
  case EFI_RESET_SHUTDOWN:
#ifdef CONFIG_CMD_POWEROFF
    do_poweroff(NULL, 0, 0, NULL);
#endif
    break;
  }

  while (1) { }
}

/**
 * efi_get_time_boottime() - get current time at boot time
 *
 * This function implements the GetTime runtime service before
 * SetVirtualAddressMap() is called.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @time:   pointer to structure to receive current time
 * @capabilities: pointer to structure to receive RTC properties
 * Returns:   status code
 */
static efi_status_t EFIAPI efi_get_time_boottime(
      struct efi_time *time,
      struct efi_time_cap *capabilities)
{
#ifdef CONFIG_EFI_GET_TIME
  efi_status_t ret = EFI_SUCCESS;
  struct rtc_time tm;
  struct udevice *dev;

  EFI_ENTRY("%p %p", time, capabilities);

  if (!time) {
    ret = EFI_INVALID_PARAMETER;
    goto out;
  }
  if (uclass_get_device(UCLASS_RTC, 0, &dev) ||
      dm_rtc_get(dev, &tm)) {
    ret = EFI_UNSUPPORTED;
    goto out;
  }
  if (dm_rtc_get(dev, &tm)) {
    ret = EFI_DEVICE_ERROR;
    goto out;
  }

  memset(time, 0, sizeof(*time));
  time->year = tm.tm_year;
  time->month = tm.tm_mon;
  time->day = tm.tm_mday;
  time->hour = tm.tm_hour;
  time->minute = tm.tm_min;
  time->second = tm.tm_sec;
  if (tm.tm_isdst > 0)
    time->daylight =
      EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT;
  else if (!tm.tm_isdst)
    time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
  else
    time->daylight = 0;
  time->timezone = EFI_UNSPECIFIED_TIMEZONE;

  if (capabilities) {
    /* Set reasonable dummy values */
    capabilities->resolution = 1;   /* 1 Hz */
    capabilities->accuracy = 100000000; /* 100 ppm */
    capabilities->sets_to_zero = false;
  }
out:
  return EFI_EXIT(ret);
#else
  EFI_ENTRY("%p %p", time, capabilities);
  return EFI_EXIT(EFI_UNSUPPORTED);
#endif
}

#ifdef CONFIG_EFI_SET_TIME

/**
 * efi_validate_time() - checks if timestamp is valid
 *
 * @time: timestamp to validate
 * Returns: 0 if timestamp is valid, 1 otherwise
 */
static int efi_validate_time(struct efi_time *time)
{
  return (!time ||
    time->year < 1900 || time->year > 9999 ||
    !time->month || time->month > 12 || !time->day ||
    time->day > rtc_month_days(time->month - 1, time->year) ||
    time->hour > 23 || time->minute > 59 || time->second > 59 ||
    time->nanosecond > 999999999 ||
    time->daylight &
    ~(EFI_TIME_IN_DAYLIGHT | EFI_TIME_ADJUST_DAYLIGHT) ||
    ((time->timezone < -1440 || time->timezone > 1440) &&
    time->timezone != EFI_UNSPECIFIED_TIMEZONE));
}

#endif

/**
 * efi_set_time_boottime() - set current time
 *
 * This function implements the SetTime() runtime service before
 * SetVirtualAddressMap() is called.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @time:   pointer to structure to with current time
 * Returns:   status code
 */
static efi_status_t EFIAPI efi_set_time_boottime(struct efi_time *time)
{
#ifdef CONFIG_EFI_SET_TIME
  efi_status_t ret = EFI_SUCCESS;
  struct rtc_time tm;
  struct udevice *dev;

  EFI_ENTRY("%p", time);

  if (efi_validate_time(time)) {
    ret = EFI_INVALID_PARAMETER;
    goto out;
  }

  if (uclass_get_device(UCLASS_RTC, 0, &dev)) {
    ret = EFI_UNSUPPORTED;
    goto out;
  }

  memset(&tm, 0, sizeof(tm));
  tm.tm_year = time->year;
  tm.tm_mon = time->month;
  tm.tm_mday = time->day;
  tm.tm_hour = time->hour;
  tm.tm_min = time->minute;
  tm.tm_sec = time->second;
  switch (time->daylight) {
  case EFI_TIME_ADJUST_DAYLIGHT:
    tm.tm_isdst = 0;
    break;
  case EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT:
    tm.tm_isdst = 1;
    break;
  default:
    tm.tm_isdst = -1;
    break;
  }
  /* Calculate day of week */
  rtc_calc_weekday(&tm);

  if (dm_rtc_set(dev, &tm))
    ret = EFI_DEVICE_ERROR;
out:
  return EFI_EXIT(ret);
#else
  EFI_ENTRY("%p", time);
  return EFI_EXIT(EFI_UNSUPPORTED);
#endif
}
/**
 * efi_reset_system() - reset system
 *
 * This function implements the ResetSystem() runtime service after
 * SetVirtualAddressMap() is called. As this placeholder cannot reset the
 * system it simply return to the caller.
 *
 * Boards may override the helpers below to implement reset functionality.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @reset_type:   type of reset to perform
 * @reset_status: status code for the reset
 * @data_size:    size of reset_data
 * @reset_data:   information about the reset
 */
void __weak __efi_runtime EFIAPI efi_reset_system(
      enum efi_reset_type reset_type,
      efi_status_t reset_status,
      unsigned long data_size, void *reset_data)
{
  return;
}

/**
 * efi_reset_system_init() - initialize the reset driver
 *
 * Boards may override this function to initialize the reset driver.
 */
efi_status_t __weak efi_reset_system_init(void)
{
  return EFI_SUCCESS;
}

/**
 * efi_get_time() - get current time
 *
 * This function implements the GetTime runtime service after
 * SetVirtualAddressMap() is called. As the U-Boot driver are not available
 * anymore only an error code is returned.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @time:   pointer to structure to receive current time
 * @capabilities: pointer to structure to receive RTC properties
 * Returns:   status code
 */
efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
      struct efi_time *time,
      struct efi_time_cap *capabilities)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_set_time() - set current time
 *
 * This function implements the SetTime runtime service after
 * SetVirtualAddressMap() is called. As the U-Boot driver are not available
 * anymore only an error code is returned.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @time:   pointer to structure to with current time
 * Returns:   status code
 */
efi_status_t __weak __efi_runtime EFIAPI efi_set_time(struct efi_time *time)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_update_capsule_unsupported() - process information from operating system
 *
 * This function implements the UpdateCapsule() runtime service.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @capsule_header_array: pointer to array of virtual pointers
 * @capsule_count:    number of pointers in capsule_header_array
 * @scatter_gather_list:  pointer to array of physical pointers
 * Returns:     status code
 */
static efi_status_t __efi_runtime EFIAPI efi_update_capsule_unsupported(
      struct efi_capsule_header **capsule_header_array,
      efi_uintn_t capsule_count,
      u64 scatter_gather_list)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_query_capsule_caps_unsupported() - check if capsule is supported
 *
 * This function implements the QueryCapsuleCapabilities() runtime service.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @capsule_header_array: pointer to array of virtual pointers
 * @capsule_count:    number of pointers in capsule_header_array
 * @maximum_capsule_size: maximum capsule size
 * @reset_type:     type of reset needed for capsule update
 * Returns:     status code
 */
static efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps_unsupported(
      struct efi_capsule_header **capsule_header_array,
      efi_uintn_t capsule_count,
      u64 *maximum_capsule_size,
      u32 *reset_type)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_is_runtime_service_pointer() - check if pointer points to runtime table
 *
 * @p:    pointer to check
 * Return:  true if the pointer points to a service function pointer in the
 *    runtime table
 */
static bool efi_is_runtime_service_pointer(void *p)
{
  return (p >= (void *)&efi_runtime_services.get_time &&
    p <= (void *)&efi_runtime_services.query_variable_info) ||
         p == (void *)&efi_events.prev ||
         p == (void *)&efi_events.next;
}

/**
 * efi_runtime_detach() - detach unimplemented runtime functions
 */
void efi_runtime_detach(void)
{
  efi_runtime_services.reset_system = efi_reset_system;
  efi_runtime_services.get_time = efi_get_time;
  efi_runtime_services.set_time = efi_set_time;
  if (IS_ENABLED(CONFIG_EFI_RUNTIME_UPDATE_CAPSULE)) {
    /* won't support at runtime */
    efi_runtime_services.update_capsule =
        efi_update_capsule_unsupported;
    efi_runtime_services.query_capsule_caps =
        efi_query_capsule_caps_unsupported;
  }

  /* Update CRC32 */
  efi_update_table_header_crc32(&efi_runtime_services.hdr);
}

/**
 * efi_set_virtual_address_map_runtime() - change from physical to virtual
 *             mapping
 *
 * This function implements the SetVirtualAddressMap() runtime service after
 * it is first called.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @memory_map_size:  size of the virtual map
 * @descriptor_size:  size of an entry in the map
 * @descriptor_version: version of the map entries
 * @virtmap:    virtual address mapping information
 * Return:    status code EFI_UNSUPPORTED
 */
static __efi_runtime efi_status_t EFIAPI efi_set_virtual_address_map_runtime(
      efi_uintn_t memory_map_size,
      efi_uintn_t descriptor_size,
      uint32_t descriptor_version,
      struct efi_mem_desc *virtmap)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_convert_pointer_runtime() - convert from physical to virtual pointer
 *
 * This function implements the ConvertPointer() runtime service after
 * the first call to SetVirtualAddressMap().
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @debug_disposition:  indicates if pointer may be converted to NULL
 * @address:    pointer to be converted
 * Return:    status code EFI_UNSUPPORTED
 */
static __efi_runtime efi_status_t EFIAPI efi_convert_pointer_runtime(
      efi_uintn_t debug_disposition, void **address)
{
  return EFI_UNSUPPORTED;
}

/**
 * efi_convert_pointer() - convert from physical to virtual pointer
 *
 * This function implements the ConvertPointer() runtime service until
 * the first call to SetVirtualAddressMap().
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @debug_disposition:  indicates if pointer may be converted to NULL
 * @address:    pointer to be converted
 * Return:    status code
 */
__efi_runtime efi_status_t EFIAPI
efi_convert_pointer(efi_uintn_t debug_disposition, void **address)
{
  efi_physical_addr_t addr;
  efi_uintn_t i;
  efi_status_t ret = EFI_NOT_FOUND;

  if (!efi_virtmap) {
    ret = EFI_UNSUPPORTED;
    goto out;
  }

  if (!address) {
    ret = EFI_INVALID_PARAMETER;
    goto out;
  }
  if (!*address) {
    if (debug_disposition & EFI_OPTIONAL_PTR)
      return EFI_SUCCESS;
    else
      return EFI_INVALID_PARAMETER;
  }

  addr = (uintptr_t)*address;
  for (i = 0; i < efi_descriptor_count; i++) {
    struct efi_mem_desc *map = (void *)efi_virtmap +
             (efi_descriptor_size * i);

    if (addr >= map->physical_start &&
        (addr < map->physical_start
          + (map->num_pages << EFI_PAGE_SHIFT))) {
      *address = (void *)(uintptr_t)
           (addr + map->virtual_start -
            map->physical_start);

      ret = EFI_SUCCESS;
      break;
    }
  }

out:
  return ret;
}

static __efi_runtime void efi_relocate_runtime_table(ulong offset)
{
  ulong patchoff;
  void **pos;

  /* Relocate the runtime services pointers */
  patchoff = offset - gd->relocaddr;
  for (pos = (void **)&efi_runtime_services.get_time;
       pos <= (void **)&efi_runtime_services.query_variable_info; ++pos) {
    if (*pos)
      *pos += patchoff;
  }

  /*
   * The entry for SetVirtualAddress() must point to a physical address.
   * After the first execution the service must return EFI_UNSUPPORTED.
   */
  efi_runtime_services.set_virtual_address_map =
      &efi_set_virtual_address_map_runtime;

  /*
   * The entry for ConvertPointer() must point to a physical address.
   * The service is not usable after SetVirtualAddress().
   */
  efi_runtime_services.convert_pointer = &efi_convert_pointer_runtime;

  /*
   * TODO: Update UEFI variable RuntimeServicesSupported removing flags
   * EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP and
   * EFI_RT_SUPPORTED_CONVERT_POINTER as required by the UEFI spec 2.8.
   */

  /* Update CRC32 */
  efi_update_table_header_crc32(&efi_runtime_services.hdr);
}

/* Relocate EFI runtime to uboot_reloc_base = offset */
void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
{
#ifdef IS_RELA
  struct elf_rela *rel = (void *)__efi_runtime_rel_start;
#else
  struct elf_rel *rel = (void *)__efi_runtime_rel_start;
  static ulong lastoff = CONFIG_TEXT_BASE;
#endif

  debug("%s: Relocating to offset=%lx\n", __func__, offset);
  for (; (uintptr_t)rel < (uintptr_t)__efi_runtime_rel_stop; rel++) {
    ulong base = CONFIG_TEXT_BASE;
    ulong *p;
    ulong newaddr;

    p = (void*)((ulong)rel->offset - base) + gd->relocaddr;

    /*
     * The runtime services table is updated in
     * efi_relocate_runtime_table()
     */
    if (map && efi_is_runtime_service_pointer(p))
      continue;

    debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__,
          rel->info, *p, rel->offset);

    switch (rel->info & R_MASK) {
    case R_RELATIVE:
#ifdef IS_RELA
    newaddr = rel->addend + offset - CONFIG_TEXT_BASE;
#else
    newaddr = *p - lastoff + offset;
#endif
      break;
#ifdef R_ABSOLUTE
    case R_ABSOLUTE: {
      ulong symidx = rel->info >> SYM_INDEX;
      extern struct dyn_sym __dyn_sym_start[];
      newaddr = __dyn_sym_start[symidx].addr + offset;
#ifdef IS_RELA
      newaddr -= CONFIG_TEXT_BASE;
#endif
      break;
    }
#endif
    default:
      printf("%s: Unknown relocation type %llx\n",
             __func__, rel->info & R_MASK);
      continue;
    }

    /* Check if the relocation is inside bounds */
    if (map && ((newaddr < map->virtual_start) ||
        newaddr > (map->virtual_start +
            (map->num_pages << EFI_PAGE_SHIFT)))) {
      printf("%s: Relocation at %p is out of range (%lx)\n",
             __func__, p, newaddr);
      continue;
    }

    debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
    *p = newaddr;
    flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
      ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
  }

#ifndef IS_RELA
  lastoff = offset;
#endif

  /*
   * If on x86 a write affects a prefetched instruction,
   * the prefetch queue is invalidated.
   */
  if (!CONFIG_IS_ENABLED(X86))
    invalidate_icache_all();
}

/**
 * efi_set_virtual_address_map() - change from physical to virtual mapping
 *
 * This function implements the SetVirtualAddressMap() runtime service.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @memory_map_size:  size of the virtual map
 * @descriptor_size:  size of an entry in the map
 * @descriptor_version: version of the map entries
 * @virtmap:    virtual address mapping information
 * Return:    status code
 */
static efi_status_t EFIAPI efi_set_virtual_address_map(
      efi_uintn_t memory_map_size,
      efi_uintn_t descriptor_size,
      uint32_t descriptor_version,
      struct efi_mem_desc *virtmap)
{
  efi_uintn_t n = memory_map_size / descriptor_size;
  efi_uintn_t i;
  efi_status_t ret = EFI_INVALID_PARAMETER;
  int rt_code_sections = 0;
  struct efi_event *event;

  EFI_ENTRY("%zx %zx %x %p", memory_map_size, descriptor_size,
      descriptor_version, virtmap);

  if (descriptor_version != EFI_MEMORY_DESCRIPTOR_VERSION ||
      descriptor_size < sizeof(struct efi_mem_desc))
    goto out;

  efi_virtmap = virtmap;
  efi_descriptor_size = descriptor_size;
  efi_descriptor_count = n;

  /*
   * TODO:
   * Further down we are cheating. While really we should implement
   * SetVirtualAddressMap() events and ConvertPointer() to allow
   * dynamically loaded drivers to expose runtime services, we don't
   * today.
   *
   * So let's ensure we see exactly one single runtime section, as
   * that is the built-in one. If we see more (or less), someone must
   * have tried adding or removing to that which we don't support yet.
   * In that case, let's better fail rather than expose broken runtime
   * services.
   */
  for (i = 0; i < n; i++) {
    struct efi_mem_desc *map = (void*)virtmap +
             (descriptor_size * i);

    if (map->type == EFI_RUNTIME_SERVICES_CODE)
      rt_code_sections++;
  }

  if (rt_code_sections != 1) {
    /*
     * We expose exactly one single runtime code section, so
     * something is definitely going wrong.
     */
    goto out;
  }

  /* Notify EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE */
  list_for_each_entry(event, &efi_events, link) {
    if (event->notify_function)
      EFI_CALL_VOID(event->notify_function(
          event, event->notify_context));
  }

  /* Rebind mmio pointers */
  for (i = 0; i < n; i++) {
    struct efi_mem_desc *map = (void*)virtmap +
             (descriptor_size * i);
    struct list_head *lhandle;
    efi_physical_addr_t map_start = map->physical_start;
    efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
    efi_physical_addr_t map_end = map_start + map_len;
    u64 off = map->virtual_start - map_start;

    /* Adjust all mmio pointers in this region */
    list_for_each(lhandle, &efi_runtime_mmio) {
      struct efi_runtime_mmio_list *lmmio;

      lmmio = list_entry(lhandle,
             struct efi_runtime_mmio_list,
             link);
      if ((map_start <= lmmio->paddr) &&
          (map_end >= lmmio->paddr)) {
        uintptr_t new_addr = lmmio->paddr + off;
        *lmmio->ptr = (void *)new_addr;
      }
    }
    if ((map_start <= (uintptr_t)systab.tables) &&
        (map_end >= (uintptr_t)systab.tables)) {
      char *ptr = (char *)systab.tables;

      ptr += off;
      systab.tables = (struct efi_configuration_table *)ptr;
    }
  }

  /* Relocate the runtime. See TODO above */
  for (i = 0; i < n; i++) {
    struct efi_mem_desc *map;

    map = (void*)virtmap + (descriptor_size * i);
    if (map->type == EFI_RUNTIME_SERVICES_CODE) {
      ulong new_offset = map->virtual_start -
             map->physical_start + gd->relocaddr;

      efi_relocate_runtime_table(new_offset);
      efi_runtime_relocate(new_offset, map);
      ret = EFI_SUCCESS;
      goto out;
    }
  }

out:
  return EFI_EXIT(ret);
}

/**
 * efi_add_runtime_mmio() - add memory-mapped IO region
 *
 * This function adds a memory-mapped IO region to the memory map to make it
 * available at runtime.
 *
 * @mmio_ptr:   pointer to a pointer to the start of the memory-mapped
 *      IO region
 * @len:    size of the memory-mapped IO region
 * Returns:   status code
 */
efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
{
  struct efi_runtime_mmio_list *newmmio;
  uint64_t addr = *(uintptr_t *)mmio_ptr;
  efi_status_t ret;

  ret = efi_add_memory_map(addr, len, EFI_MMAP_IO);
  if (ret != EFI_SUCCESS)
    return EFI_OUT_OF_RESOURCES;

  newmmio = calloc(1, sizeof(*newmmio));
  if (!newmmio)
    return EFI_OUT_OF_RESOURCES;
  newmmio->ptr = mmio_ptr;
  newmmio->paddr = *(uintptr_t *)mmio_ptr;
  newmmio->len = len;
  list_add_tail(&newmmio->link, &efi_runtime_mmio);

  return EFI_SUCCESS;
}

/*
 * In the second stage, U-Boot has disappeared. To isolate our runtime code
 * that at this point still exists from the rest, we put it into a special
 * section.
 *
 *        !!WARNING!!
 *
 * This means that we can not rely on any code outside of this file in any
 * function or variable below this line.
 *
 * Please keep everything fully self-contained and annotated with
 * __efi_runtime and __efi_runtime_data markers.
 */

/*
 * Relocate the EFI runtime stub to a different place. We need to call this
 * the first time we expose the runtime interface to a user and on set virtual
 * address map calls.
 */

/**
 * efi_unimplemented() - replacement function, returns EFI_UNSUPPORTED
 *
 * This function is used after SetVirtualAddressMap() is called as replacement
 * for services that are not available anymore due to constraints of the U-Boot
 * implementation.
 *
 * Return:  EFI_UNSUPPORTED
 */
static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
{
  return EFI_UNSUPPORTED;
}

struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
  .hdr = {
    .signature = EFI_RUNTIME_SERVICES_SIGNATURE,
    .revision = EFI_SPECIFICATION_VERSION,
    .headersize = sizeof(struct efi_runtime_services),
  },
  .get_time = &efi_get_time_boottime,
  .set_time = &efi_set_time_boottime,
  .get_wakeup_time = (void *)&efi_unimplemented,
  .set_wakeup_time = (void *)&efi_unimplemented,
  .set_virtual_address_map = &efi_set_virtual_address_map,
  .convert_pointer = efi_convert_pointer,
  .get_variable = efi_get_variable,
  .get_next_variable_name = efi_get_next_variable_name,
  .set_variable = efi_set_variable,
  .get_next_high_mono_count = (void *)&efi_unimplemented,
  .reset_system = &efi_reset_system_boottime,
#ifdef CONFIG_EFI_RUNTIME_UPDATE_CAPSULE
  .update_capsule = efi_update_capsule,
  .query_capsule_caps = efi_query_capsule_caps,
#else
  .update_capsule = efi_update_capsule_unsupported,
  .query_capsule_caps = efi_query_capsule_caps_unsupported,
#endif
  .query_variable_info = efi_query_variable_info,
};

Coverage Report

Created: 2026-03-11 06:21