efi_loader: Add runtime services

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>
This commit is contained in:
Alexander Graf 2016-03-04 01:10:01 +01:00 committed by Tom Rini
parent c1311ad4e0
commit 50149ea37a
9 changed files with 398 additions and 3 deletions

View File

@ -122,6 +122,10 @@ ifdef CONFIG_OF_EMBED
OBJCOPYFLAGS += -j .dtb.init.rodata
endif
ifdef CONFIG_EFI_LOADER
OBJCOPYFLAGS += -j .efi_runtime -j .efi_runtime_rel
endif
ifneq ($(CONFIG_IMX_CONFIG),)
ifdef CONFIG_SPL
ifndef CONFIG_SPL_BUILD

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@ -42,6 +42,22 @@ SECTIONS
. = ALIGN(8);
.efi_runtime : {
__efi_runtime_start = .;
*(efi_runtime_text)
*(efi_runtime_data)
__efi_runtime_stop = .;
}
.efi_runtime_rel : {
__efi_runtime_rel_start = .;
*(.relaefi_runtime_text)
*(.relaefi_runtime_data)
__efi_runtime_rel_stop = .;
}
. = ALIGN(8);
.image_copy_end :
{
*(.__image_copy_end)

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@ -90,6 +90,36 @@ SECTIONS
. = ALIGN(4);
.__efi_runtime_start : {
*(.__efi_runtime_start)
}
.efi_runtime : {
*(efi_runtime_text)
*(efi_runtime_data)
}
.__efi_runtime_stop : {
*(.__efi_runtime_stop)
}
.efi_runtime_rel_start :
{
*(.__efi_runtime_rel_start)
}
.efi_runtime_rel : {
*(.relefi_runtime_text)
*(.relefi_runtime_data)
}
.efi_runtime_rel_stop :
{
*(.__efi_runtime_rel_stop)
}
. = ALIGN(4);
.image_copy_end :
{
*(.__image_copy_end)

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@ -27,4 +27,8 @@ char __rel_dyn_start[0] __attribute__((section(".__rel_dyn_start")));
char __rel_dyn_end[0] __attribute__((section(".__rel_dyn_end")));
char __secure_start[0] __attribute__((section(".__secure_start")));
char __secure_end[0] __attribute__((section(".__secure_end")));
char __efi_runtime_start[0] __attribute__((section(".__efi_runtime_start")));
char __efi_runtime_stop[0] __attribute__((section(".__efi_runtime_stop")));
char __efi_runtime_rel_start[0] __attribute__((section(".__efi_runtime_rel_start")));
char __efi_runtime_rel_stop[0] __attribute__((section(".__efi_runtime_rel_stop")));
char _end[0] __attribute__((section(".__end")));

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@ -59,6 +59,36 @@ SECTIONS
. = ALIGN(4);
.__efi_runtime_start : {
*(.__efi_runtime_start)
}
.efi_runtime : {
*(efi_runtime_text)
*(efi_runtime_data)
}
.__efi_runtime_stop : {
*(.__efi_runtime_stop)
}
.efi_runtime_rel_start :
{
*(.__efi_runtime_rel_start)
}
.efi_runtime_rel : {
*(.relefi_runtime_text)
*(.relefi_runtime_data)
}
.efi_runtime_rel_stop :
{
*(.__efi_runtime_rel_stop)
}
. = ALIGN(4);
.image_copy_end :
{
*(.__image_copy_end)

View File

@ -65,6 +65,7 @@
#ifdef CONFIG_AVR32
#include <asm/arch/mmu.h>
#endif
#include <efi_loader.h>
DECLARE_GLOBAL_DATA_PTR;
@ -177,6 +178,9 @@ static int initr_reloc_global_data(void)
*/
gd->fdt_blob += gd->reloc_off;
#endif
#ifdef CONFIG_EFI_LOADER
efi_runtime_relocate(gd->relocaddr, NULL);
#endif
return 0;
}

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@ -30,6 +30,7 @@
#define EFI_EXIT(ret) efi_exit_func(ret);
extern struct efi_runtime_services efi_runtime_services;
extern struct efi_system_table systab;
extern const struct efi_simple_text_output_protocol efi_con_out;
@ -40,6 +41,9 @@ extern const efi_guid_t efi_guid_console_control;
extern const efi_guid_t efi_guid_device_path;
extern const efi_guid_t efi_guid_loaded_image;
extern unsigned int __efi_runtime_start, __efi_runtime_stop;
extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
/*
* While UEFI objects can have callbacks, you can also call functions on
* protocols (classes) themselves. This struct maps a protocol GUID to its
@ -101,9 +105,22 @@ void efi_save_gd(void);
void efi_restore_gd(void);
/* Called from EFI_EXIT on callback exit to restore the gd register */
efi_status_t efi_exit_func(efi_status_t ret);
/* Call this to relocate the runtime section to an address space */
void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map);
/*
* Use these to indicate that your code / data should go into the EFI runtime
* section and thus still be available when the OS is running
*/
#define EFI_RUNTIME_DATA __attribute__ ((section ("efi_runtime_data")))
#define EFI_RUNTIME_TEXT __attribute__ ((section ("efi_runtime_text")))
#else /* defined(EFI_LOADER) && !defined(CONFIG_SPL_BUILD) */
/* Without CONFIG_EFI_LOADER we don't have a runtime section, stub it out */
#define EFI_RUNTIME_DATA
#define EFI_RUNTIME_TEXT
/* No loader configured, stub out EFI_ENTRY */
static inline void efi_restore_gd(void) { }

View File

@ -39,7 +39,7 @@ static bool efi_is_direct_boot = true;
* In most cases we want to pass an FDT to the payload, so reserve one slot of
* config table space for it. The pointer gets populated by do_bootefi_exec().
*/
static struct efi_configuration_table efi_conf_table[1];
static struct efi_configuration_table EFI_RUNTIME_DATA efi_conf_table[1];
/*
* The "gd" pointer lives in a register on ARM and AArch64 that we declare
@ -761,10 +761,10 @@ static const struct efi_boot_services efi_boot_services = {
};
static uint16_t firmware_vendor[] =
static uint16_t EFI_RUNTIME_DATA firmware_vendor[] =
{ 'D','a','s',' ','U','-','b','o','o','t',0 };
struct efi_system_table systab = {
struct efi_system_table EFI_RUNTIME_DATA systab = {
.hdr = {
.signature = EFI_SYSTEM_TABLE_SIGNATURE,
.revision = 0x20005, /* 2.5 */

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@ -0,0 +1,290 @@
/*
* EFI application runtime services
*
* Copyright (c) 2016 Alexander Graf
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <dm.h>
#include <efi_loader.h>
#include <rtc.h>
#include <asm/global_data.h>
/* For manual relocation support */
DECLARE_GLOBAL_DATA_PTR;
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void);
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void);
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void);
#if defined(CONFIG_ARM64)
#define R_RELATIVE 1027
#define R_MASK 0xffffffffULL
#define IS_RELA 1
#elif defined(CONFIG_ARM)
#define R_RELATIVE 23
#define R_MASK 0xffULL
#else
#error Need to add relocation awareness
#endif
struct elf_rel {
ulong *offset;
ulong info;
};
struct elf_rela {
ulong *offset;
ulong info;
long addend;
};
/*
* EFI Runtime code lives in 2 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
*/
static void EFIAPI efi_reset_system(enum efi_reset_type reset_type,
efi_status_t reset_status,
unsigned long data_size, void *reset_data)
{
EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
reset_data);
switch (reset_type) {
case EFI_RESET_COLD:
case EFI_RESET_WARM:
do_reset(NULL, 0, 0, NULL);
break;
case EFI_RESET_SHUTDOWN:
/* We don't have anything to map this to */
break;
}
EFI_EXIT(EFI_SUCCESS);
}
static efi_status_t EFIAPI efi_get_time(struct efi_time *time,
struct efi_time_cap *capabilities)
{
#if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
struct rtc_time tm;
int r;
struct udevice *dev;
EFI_ENTRY("%p %p", time, capabilities);
r = uclass_get_device(UCLASS_RTC, 0, &dev);
if (r)
return EFI_EXIT(EFI_DEVICE_ERROR);
r = dm_rtc_get(dev, &tm);
if (r)
return EFI_EXIT(EFI_DEVICE_ERROR);
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->daylight = tm.tm_isdst;
return EFI_EXIT(EFI_SUCCESS);
#else
return EFI_DEVICE_ERROR;
#endif
}
struct efi_runtime_detach_list_struct {
void *ptr;
void *patchto;
};
static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
{
/* do_reset is gone */
.ptr = &efi_runtime_services.reset_system,
.patchto = NULL,
}, {
/* invalidate_*cache_all are gone */
.ptr = &efi_runtime_services.set_virtual_address_map,
.patchto = &efi_invalid_parameter,
}, {
/* RTC accessors are gone */
.ptr = &efi_runtime_services.get_time,
.patchto = &efi_device_error,
},
};
static bool efi_runtime_tobedetached(void *p)
{
int i;
for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
if (efi_runtime_detach_list[i].ptr == p)
return true;
return false;
}
static void efi_runtime_detach(ulong offset)
{
int i;
ulong patchoff = offset - (ulong)gd->relocaddr;
for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
ulong *p = efi_runtime_detach_list[i].ptr;
ulong newaddr = patchto ? (patchto + patchoff) : 0;
#ifdef DEBUG_EFI
printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
#endif
*p = newaddr;
}
}
/* 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
#ifdef DEBUG_EFI
printf("%s: Relocating to offset=%lx\n", __func__, offset);
#endif
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;
if ((rel->info & R_MASK) != R_RELATIVE) {
continue;
}
#ifdef IS_RELA
newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
#else
newaddr = *p - lastoff + offset;
#endif
/* Check if the relocation is inside bounds */
if (map && ((newaddr < map->virtual_start) ||
newaddr > (map->virtual_start + (map->num_pages << 12)))) {
if (!efi_runtime_tobedetached(p))
printf("U-Boot EFI: Relocation at %p is out of "
"range (%lx)\n", p, newaddr);
continue;
}
#ifdef DEBUG_EFI
printf("%s: Setting %p to %lx\n", __func__, p, newaddr);
#endif
*p = newaddr;
flush_dcache_range((ulong)p, (ulong)&p[1]);
}
#ifndef IS_RELA
lastoff = offset;
#endif
invalidate_icache_all();
}
static efi_status_t EFIAPI efi_set_virtual_address_map(
unsigned long memory_map_size,
unsigned long descriptor_size,
uint32_t descriptor_version,
struct efi_mem_desc *virtmap)
{
ulong runtime_start = (ulong)&__efi_runtime_start & ~0xfffULL;
int n = memory_map_size / descriptor_size;
int i;
EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
descriptor_version, virtmap);
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 - (runtime_start - gd->relocaddr);
efi_runtime_relocate(new_offset, map);
/* Once we're virtual, we can no longer handle
complex callbacks */
efi_runtime_detach(new_offset);
return EFI_EXIT(EFI_SUCCESS);
}
}
return EFI_EXIT(EFI_INVALID_PARAMETER);
}
/*
* 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_TEXT 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.
*/
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_unimplemented(void)
{
return EFI_UNSUPPORTED;
}
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_device_error(void)
{
return EFI_DEVICE_ERROR;
}
static efi_status_t EFI_RUNTIME_TEXT EFIAPI efi_invalid_parameter(void)
{
return EFI_INVALID_PARAMETER;
}
struct efi_runtime_services EFI_RUNTIME_DATA efi_runtime_services = {
.hdr = {
.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
.revision = EFI_RUNTIME_SERVICES_REVISION,
.headersize = sizeof(struct efi_table_hdr),
},
.get_time = &efi_get_time,
.set_time = (void *)&efi_device_error,
.get_wakeup_time = (void *)&efi_unimplemented,
.set_wakeup_time = (void *)&efi_unimplemented,
.set_virtual_address_map = &efi_set_virtual_address_map,
.convert_pointer = (void *)&efi_invalid_parameter,
.get_variable = (void *)&efi_device_error,
.get_next_variable = (void *)&efi_device_error,
.set_variable = (void *)&efi_device_error,
.get_next_high_mono_count = (void *)&efi_device_error,
.reset_system = &efi_reset_system,
};