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

#include <common.h>
#include <command.h>
#include <cpu_func.h>
#include <dm.h>
#include <elf.h>
#include <efi_loader.h>
#include <log.h>
#include <malloc.h>
#include <rtc.h>
#include <asm/global_data.h>
#include <u-boot/crc.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 */
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)
{
        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;

        /*
         * 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
 */
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
 */
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_SYS_TEXT_BASE;
#endif

        debug("%s: Relocating to offset=%lx\n", __func__, offset);
        for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
                ulong base = CONFIG_SYS_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_SYS_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_SYS_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

        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,
};