After booting has finished, EFI allows firmware to still interact with the OS using the "runtime services". These callbacks live in a separate address space, since they are available long after U-Boot has been overwritten by the OS. This patch adds enough framework for arbitrary code inside of U-Boot to become a runtime service with the right section attributes set. For now, we don't make use of it yet though. We could maybe in the future map U-boot environment variables to EFI variables here. Signed-off-by: Alexander Graf <agraf@suse.de> Reviewed-by: Simon Glass <sjg@chromium.org> Tested-by: Simon Glass <sjg@chromium.org>master
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/*
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* EFI application runtime services |
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* |
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* Copyright (c) 2016 Alexander Graf |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#include <common.h> |
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#include <command.h> |
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#include <dm.h> |
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#include <efi_loader.h> |
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#include <rtc.h> |
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#include <asm/global_data.h> |
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/* For manual relocation support */ |
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DECLARE_GLOBAL_DATA_PTR; |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void); |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void); |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void); |
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#if defined(CONFIG_ARM64) |
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#define R_RELATIVE 1027 |
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#define R_MASK 0xffffffffULL |
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#define IS_RELA 1 |
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#elif defined(CONFIG_ARM) |
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#define R_RELATIVE 23 |
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#define R_MASK 0xffULL |
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#else |
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#error Need to add relocation awareness |
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#endif |
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struct elf_rel { |
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ulong *offset; |
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ulong info; |
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}; |
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struct elf_rela { |
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ulong *offset; |
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ulong info; |
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long addend; |
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}; |
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/*
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* EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI |
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* payload are running concurrently at the same time. In this mode, we can |
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* handle a good number of runtime callbacks |
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*/ |
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static void EFIAPI efi_reset_system(enum efi_reset_type reset_type, |
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efi_status_t reset_status, |
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unsigned long data_size, void *reset_data) |
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{ |
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EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size, |
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reset_data); |
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switch (reset_type) { |
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case EFI_RESET_COLD: |
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case EFI_RESET_WARM: |
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do_reset(NULL, 0, 0, NULL); |
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break; |
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case EFI_RESET_SHUTDOWN: |
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/* We don't have anything to map this to */ |
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break; |
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} |
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EFI_EXIT(EFI_SUCCESS); |
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} |
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static efi_status_t EFIAPI efi_get_time(struct efi_time *time, |
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struct efi_time_cap *capabilities) |
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{ |
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#if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC) |
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struct rtc_time tm; |
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int r; |
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struct udevice *dev; |
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EFI_ENTRY("%p %p", time, capabilities); |
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r = uclass_get_device(UCLASS_RTC, 0, &dev); |
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if (r) |
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return EFI_EXIT(EFI_DEVICE_ERROR); |
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r = dm_rtc_get(dev, &tm); |
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if (r) |
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return EFI_EXIT(EFI_DEVICE_ERROR); |
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memset(time, 0, sizeof(*time)); |
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time->year = tm.tm_year; |
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time->month = tm.tm_mon; |
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time->day = tm.tm_mday; |
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time->hour = tm.tm_hour; |
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time->minute = tm.tm_min; |
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time->daylight = tm.tm_isdst; |
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return EFI_EXIT(EFI_SUCCESS); |
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#else |
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return EFI_DEVICE_ERROR; |
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#endif |
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} |
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struct efi_runtime_detach_list_struct { |
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void *ptr; |
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void *patchto; |
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}; |
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static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = { |
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{ |
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/* do_reset is gone */ |
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.ptr = &efi_runtime_services.reset_system, |
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.patchto = NULL, |
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}, { |
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/* invalidate_*cache_all are gone */ |
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.ptr = &efi_runtime_services.set_virtual_address_map, |
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.patchto = &efi_invalid_parameter, |
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}, { |
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/* RTC accessors are gone */ |
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.ptr = &efi_runtime_services.get_time, |
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.patchto = &efi_device_error, |
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}, |
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}; |
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static bool efi_runtime_tobedetached(void *p) |
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{ |
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int i; |
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for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) |
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if (efi_runtime_detach_list[i].ptr == p) |
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return true; |
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return false; |
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} |
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static void efi_runtime_detach(ulong offset) |
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{ |
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int i; |
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ulong patchoff = offset - (ulong)gd->relocaddr; |
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for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) { |
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ulong patchto = (ulong)efi_runtime_detach_list[i].patchto; |
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ulong *p = efi_runtime_detach_list[i].ptr; |
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ulong newaddr = patchto ? (patchto + patchoff) : 0; |
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#ifdef DEBUG_EFI |
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printf("%s: Setting %p to %lx\n", __func__, p, newaddr); |
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#endif |
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*p = newaddr; |
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} |
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} |
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/* Relocate EFI runtime to uboot_reloc_base = offset */ |
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void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map) |
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{ |
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#ifdef IS_RELA |
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struct elf_rela *rel = (void*)&__efi_runtime_rel_start; |
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#else |
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struct elf_rel *rel = (void*)&__efi_runtime_rel_start; |
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static ulong lastoff = CONFIG_SYS_TEXT_BASE; |
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#endif |
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#ifdef DEBUG_EFI |
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printf("%s: Relocating to offset=%lx\n", __func__, offset); |
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#endif |
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for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) { |
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ulong base = CONFIG_SYS_TEXT_BASE; |
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ulong *p; |
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ulong newaddr; |
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p = (void*)((ulong)rel->offset - base) + gd->relocaddr; |
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if ((rel->info & R_MASK) != R_RELATIVE) { |
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continue; |
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} |
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#ifdef IS_RELA |
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newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE; |
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#else |
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newaddr = *p - lastoff + offset; |
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#endif |
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/* Check if the relocation is inside bounds */ |
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if (map && ((newaddr < map->virtual_start) || |
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newaddr > (map->virtual_start + (map->num_pages << 12)))) { |
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if (!efi_runtime_tobedetached(p)) |
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printf("U-Boot EFI: Relocation at %p is out of " |
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"range (%lx)\n", p, newaddr); |
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continue; |
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} |
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#ifdef DEBUG_EFI |
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printf("%s: Setting %p to %lx\n", __func__, p, newaddr); |
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#endif |
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*p = newaddr; |
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flush_dcache_range((ulong)p, (ulong)&p[1]); |
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} |
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#ifndef IS_RELA |
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lastoff = offset; |
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#endif |
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invalidate_icache_all(); |
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} |
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static efi_status_t EFIAPI efi_set_virtual_address_map( |
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unsigned long memory_map_size, |
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unsigned long descriptor_size, |
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uint32_t descriptor_version, |
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struct efi_mem_desc *virtmap) |
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{ |
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ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL; |
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int n = memory_map_size / descriptor_size; |
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int i; |
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EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size, |
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descriptor_version, virtmap); |
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for (i = 0; i < n; i++) { |
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struct efi_mem_desc *map; |
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map = (void*)virtmap + (descriptor_size * i); |
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if (map->type == EFI_RUNTIME_SERVICES_CODE) { |
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ulong new_offset = map->virtual_start - (runtime_start - gd->relocaddr); |
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efi_runtime_relocate(new_offset, map); |
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/* Once we're virtual, we can no longer handle
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complex callbacks */ |
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efi_runtime_detach(new_offset); |
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return EFI_EXIT(EFI_SUCCESS); |
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} |
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} |
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return EFI_EXIT(EFI_INVALID_PARAMETER); |
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} |
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/*
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* In the second stage, U-Boot has disappeared. To isolate our runtime code |
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* that at this point still exists from the rest, we put it into a special |
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* section. |
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* |
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* !!WARNING!! |
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* |
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* This means that we can not rely on any code outside of this file in any |
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* function or variable below this line. |
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* |
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* Please keep everything fully self-contained and annotated with |
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* EFI_RUNTIME_TEXT and EFI_RUNTIME_DATA markers. |
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*/ |
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/*
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* Relocate the EFI runtime stub to a different place. We need to call this |
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* the first time we expose the runtime interface to a user and on set virtual |
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* address map calls. |
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*/ |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void) |
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{ |
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return EFI_UNSUPPORTED; |
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} |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void) |
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{ |
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return EFI_DEVICE_ERROR; |
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} |
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static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void) |
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{ |
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return EFI_INVALID_PARAMETER; |
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} |
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struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = { |
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.hdr = { |
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.signature = EFI_RUNTIME_SERVICES_SIGNATURE, |
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.revision = EFI_RUNTIME_SERVICES_REVISION, |
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.headersize = sizeof(struct efi_table_hdr), |
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}, |
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.get_time = &efi_get_time, |
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.set_time = (void *)&efi_device_error, |
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.get_wakeup_time = (void *)&efi_unimplemented, |
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.set_wakeup_time = (void *)&efi_unimplemented, |
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.set_virtual_address_map = &efi_set_virtual_address_map, |
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.convert_pointer = (void *)&efi_invalid_parameter, |
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.get_variable = (void *)&efi_device_error, |
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.get_next_variable = (void *)&efi_device_error, |
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.set_variable = (void *)&efi_device_error, |
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.get_next_high_mono_count = (void *)&efi_device_error, |
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.reset_system = &efi_reset_system, |
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}; |
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