From: Atish Patra <atish.patra@wdc.com>
Date: Wed, 15 Apr 2020 12:54:18 -0700
Subject: efi/libstub: Move arm-stub to a common file
Patch-mainline: v5.8-rc1
Git-commit: 2e0eb483c058dd013be8e3d0ec1767be531485a2
References: jsc#SLE-16407
Most of the arm-stub code is written in an architecture independent manner.
As a result, RISC-V can reuse most of the arm-stub code.
Rename the arm-stub.c to efi-stub.c so that ARM, ARM64 and RISC-V can use it.
This patch doesn't introduce any functional changes.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Link: https://lore.kernel.org/r/20200415195422.19866-2-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
arch/arm/Kconfig | 2 +-
arch/arm64/Kconfig | 2 +-
drivers/firmware/efi/Kconfig | 4 ++--
drivers/firmware/efi/libstub/Makefile | 12 ++++++------
drivers/firmware/efi/libstub/{arm-stub.c => efi-stub.c} | 0
arch/arm/Kconfig | 2
arch/arm64/Kconfig | 2
drivers/firmware/efi/Kconfig | 4
drivers/firmware/efi/libstub/Makefile | 12
drivers/firmware/efi/libstub/arm-stub.c | 412 --------------------------------
drivers/firmware/efi/libstub/efi-stub.c | 412 ++++++++++++++++++++++++++++++++
6 files changed, 422 insertions(+), 422 deletions(-)
rename drivers/firmware/efi/libstub/{arm-stub.c => efi-stub.c} (100%)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2051,7 +2051,7 @@ config EFI
select UCS2_STRING
select EFI_PARAMS_FROM_FDT
select EFI_STUB
- select EFI_ARMSTUB
+ select EFI_GENERIC_STUB
select EFI_RUNTIME_WRAPPERS
---help---
This option provides support for runtime services provided
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1614,7 +1614,7 @@ config EFI
select EFI_PARAMS_FROM_FDT
select EFI_RUNTIME_WRAPPERS
select EFI_STUB
- select EFI_ARMSTUB
+ select EFI_GENERIC_STUB
default y
help
This option provides support for runtime services provided
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -106,12 +106,12 @@ config EFI_PARAMS_FROM_FDT
config EFI_RUNTIME_WRAPPERS
bool
-config EFI_ARMSTUB
+config EFI_GENERIC_STUB
bool
config EFI_ARMSTUB_DTB_LOADER
bool "Enable the DTB loader"
- depends on EFI_ARMSTUB
+ depends on EFI_GENERIC_STUB
default y
help
Select this config option to add support for the dtb= command
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -23,7 +23,7 @@ cflags-$(CONFIG_ARM) := $(subst $(CC_FL
-fno-builtin -fpic \
$(call cc-option,-mno-single-pic-base)
-cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt
+cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt
KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
-include $(srctree)/drivers/firmware/efi/libstub/hidden.h \
@@ -45,13 +45,13 @@ lib-y := efi-stub-helper.o gop.o secu
skip_spaces.o lib-cmdline.o lib-ctype.o
# include the stub's generic dependencies from lib/ when building for ARM/arm64
-arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
+efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
$(call if_changed_rule,cc_o_c)
-lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \
- $(patsubst %.c,lib-%.o,$(arm-deps-y))
+lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o fdt.o string.o \
+ $(patsubst %.c,lib-%.o,$(efi-deps-y))
lib-$(CONFIG_ARM) += arm32-stub.o
lib-$(CONFIG_ARM64) += arm64-stub.o
@@ -73,8 +73,8 @@ CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(
# a verification pass to see if any absolute relocations exist in any of the
# object files.
#
-extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y)
-lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y))
+extra-$(CONFIG_EFI_GENERIC_STUB) := $(lib-y)
+lib-$(CONFIG_EFI_GENERIC_STUB) := $(patsubst %.o,%.stub.o,$(lib-y))
STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \
--prefix-symbols=__efistub_
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ /dev/null
@@ -1,412 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * EFI stub implementation that is shared by arm and arm64 architectures.
- * This should be #included by the EFI stub implementation files.
- *
- * Copyright (C) 2013,2014 Linaro Limited
- * Roy Franz <roy.franz@linaro.org
- * Copyright (C) 2013 Red Hat, Inc.
- * Mark Salter <msalter@redhat.com>
- */
-
-#include <linux/efi.h>
-#include <linux/libfdt.h>
-#include <asm/efi.h>
-
-#include "efistub.h"
-
-/*
- * This is the base address at which to start allocating virtual memory ranges
- * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
- * any allocation we choose, and eliminate the risk of a conflict after kexec.
- * The value chosen is the largest non-zero power of 2 suitable for this purpose
- * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
- * be mapped efficiently.
- * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
- * map everything below 1 GB. (512 MB is a reasonable upper bound for the
- * entire footprint of the UEFI runtime services memory regions)
- */
-#define EFI_RT_VIRTUAL_BASE SZ_512M
-#define EFI_RT_VIRTUAL_SIZE SZ_512M
-
-#ifdef CONFIG_ARM64
-# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
-#else
-# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
-#endif
-
-static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
-static bool __efistub_global flat_va_mapping;
-
-static efi_system_table_t *__efistub_global sys_table;
-
-__pure efi_system_table_t *efi_system_table(void)
-{
- return sys_table;
-}
-
-static struct screen_info *setup_graphics(void)
-{
- efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
- efi_status_t status;
- unsigned long size;
- void **gop_handle = NULL;
- struct screen_info *si = NULL;
-
- size = 0;
- status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
- &gop_proto, NULL, &size, gop_handle);
- if (status == EFI_BUFFER_TOO_SMALL) {
- si = alloc_screen_info();
- if (!si)
- return NULL;
- status = efi_setup_gop(si, &gop_proto, size);
- if (status != EFI_SUCCESS) {
- free_screen_info(si);
- return NULL;
- }
- }
- return si;
-}
-
-void install_memreserve_table(void)
-{
- struct linux_efi_memreserve *rsv;
- efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
- efi_status_t status;
-
- status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
- (void **)&rsv);
- if (status != EFI_SUCCESS) {
- pr_efi_err("Failed to allocate memreserve entry!\n");
- return;
- }
-
- rsv->next = 0;
- rsv->size = 0;
- atomic_set(&rsv->count, 0);
-
- status = efi_bs_call(install_configuration_table,
- &memreserve_table_guid, rsv);
- if (status != EFI_SUCCESS)
- pr_efi_err("Failed to install memreserve config table!\n");
-}
-
-static unsigned long get_dram_base(void)
-{
- efi_status_t status;
- unsigned long map_size, buff_size;
- unsigned long membase = EFI_ERROR;
- struct efi_memory_map map;
- efi_memory_desc_t *md;
- struct efi_boot_memmap boot_map;
-
- boot_map.map = (efi_memory_desc_t **)&map.map;
- boot_map.map_size = &map_size;
- boot_map.desc_size = &map.desc_size;
- boot_map.desc_ver = NULL;
- boot_map.key_ptr = NULL;
- boot_map.buff_size = &buff_size;
-
- status = efi_get_memory_map(&boot_map);
- if (status != EFI_SUCCESS)
- return membase;
-
- map.map_end = map.map + map_size;
-
- for_each_efi_memory_desc_in_map(&map, md) {
- if (md->attribute & EFI_MEMORY_WB) {
- if (membase > md->phys_addr)
- membase = md->phys_addr;
- }
- }
-
- efi_bs_call(free_pool, map.map);
-
- return membase;
-}
-
-/*
- * This function handles the architcture specific differences between arm and
- * arm64 regarding where the kernel image must be loaded and any memory that
- * must be reserved. On failure it is required to free all
- * all allocations it has made.
- */
-efi_status_t handle_kernel_image(unsigned long *image_addr,
- unsigned long *image_size,
- unsigned long *reserve_addr,
- unsigned long *reserve_size,
- unsigned long dram_base,
- efi_loaded_image_t *image);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
- unsigned long fdt_addr,
- unsigned long fdt_size);
-
-/*
- * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
- * that is described in the PE/COFF header. Most of the code is the same
- * for both archictectures, with the arch-specific code provided in the
- * handle_kernel_image() function.
- */
-efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
-{
- efi_loaded_image_t *image;
- efi_status_t status;
- unsigned long image_addr;
- unsigned long image_size = 0;
- unsigned long dram_base;
- /* addr/point and size pairs for memory management*/
- unsigned long initrd_addr = 0;
- unsigned long initrd_size = 0;
- unsigned long fdt_addr = 0; /* Original DTB */
- unsigned long fdt_size = 0;
- char *cmdline_ptr = NULL;
- int cmdline_size = 0;
- efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
- unsigned long reserve_addr = 0;
- unsigned long reserve_size = 0;
- enum efi_secureboot_mode secure_boot;
- struct screen_info *si;
- efi_properties_table_t *prop_tbl;
- unsigned long max_addr;
-
- sys_table = sys_table_arg;
-
- /* Check if we were booted by the EFI firmware */
- if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
- status = EFI_INVALID_PARAMETER;
- goto fail;
- }
-
- status = check_platform_features();
- if (status != EFI_SUCCESS)
- goto fail;
-
- /*
- * Get a handle to the loaded image protocol. This is used to get
- * information about the running image, such as size and the command
- * line.
- */
- status = sys_table->boottime->handle_protocol(handle,
- &loaded_image_proto, (void *)&image);
- if (status != EFI_SUCCESS) {
- pr_efi_err("Failed to get loaded image protocol\n");
- goto fail;
- }
-
- dram_base = get_dram_base();
- if (dram_base == EFI_ERROR) {
- pr_efi_err("Failed to find DRAM base\n");
- status = EFI_LOAD_ERROR;
- goto fail;
- }
-
- /*
- * Get the command line from EFI, using the LOADED_IMAGE
- * protocol. We are going to copy the command line into the
- * device tree, so this can be allocated anywhere.
- */
- cmdline_ptr = efi_convert_cmdline(image, &cmdline_size, ULONG_MAX);
- if (!cmdline_ptr) {
- pr_efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
- status = EFI_OUT_OF_RESOURCES;
- goto fail;
- }
-
- if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
- IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
- cmdline_size == 0)
- efi_parse_options(CONFIG_CMDLINE);
-
- if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
- efi_parse_options(cmdline_ptr);
-
- pr_efi("Booting Linux Kernel...\n");
-
- si = setup_graphics();
-
- status = handle_kernel_image(&image_addr, &image_size,
- &reserve_addr,
- &reserve_size,
- dram_base, image);
- if (status != EFI_SUCCESS) {
- pr_efi_err("Failed to relocate kernel\n");
- goto fail_free_cmdline;
- }
-
- efi_retrieve_tpm2_eventlog();
-
- /* Ask the firmware to clear memory on unclean shutdown */
- efi_enable_reset_attack_mitigation();
-
- secure_boot = efi_get_secureboot();
-
- /*
- * Unauthenticated device tree data is a security hazard, so ignore
- * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
- * boot is enabled if we can't determine its state.
- */
- if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
- secure_boot != efi_secureboot_mode_disabled) {
- if (strstr(cmdline_ptr, "dtb="))
- pr_efi("Ignoring DTB from command line.\n");
- } else {
- status = efi_load_dtb(image, &fdt_addr, &fdt_size);
-
- if (status != EFI_SUCCESS) {
- pr_efi_err("Failed to load device tree!\n");
- goto fail_free_image;
- }
- }
-
- if (fdt_addr) {
- pr_efi("Using DTB from command line\n");
- } else {
- /* Look for a device tree configuration table entry. */
- fdt_addr = (uintptr_t)get_fdt(&fdt_size);
- if (fdt_addr)
- pr_efi("Using DTB from configuration table\n");
- }
-
- if (!fdt_addr)
- pr_efi("Generating empty DTB\n");
-
- if (!noinitrd()) {
- max_addr = efi_get_max_initrd_addr(dram_base, image_addr);
- status = efi_load_initrd_dev_path(&initrd_addr, &initrd_size,
- max_addr);
- if (status == EFI_SUCCESS) {
- pr_efi("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
- } else if (status == EFI_NOT_FOUND) {
- status = efi_load_initrd(image, &initrd_addr, &initrd_size,
- ULONG_MAX, max_addr);
- if (status == EFI_SUCCESS && initrd_size > 0)
- pr_efi("Loaded initrd from command line option\n");
- }
- if (status != EFI_SUCCESS)
- pr_efi_err("Failed to load initrd!\n");
- }
-
- efi_random_get_seed();
-
- /*
- * If the NX PE data feature is enabled in the properties table, we
- * should take care not to create a virtual mapping that changes the
- * relative placement of runtime services code and data regions, as
- * they may belong to the same PE/COFF executable image in memory.
- * The easiest way to achieve that is to simply use a 1:1 mapping.
- */
- prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
- flat_va_mapping = prop_tbl &&
- (prop_tbl->memory_protection_attribute &
- EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
-
- /* hibernation expects the runtime regions to stay in the same place */
- if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr() && !flat_va_mapping) {
- /*
- * Randomize the base of the UEFI runtime services region.
- * Preserve the 2 MB alignment of the region by taking a
- * shift of 21 bit positions into account when scaling
- * the headroom value using a 32-bit random value.
- */
- static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
- EFI_RT_VIRTUAL_BASE -
- EFI_RT_VIRTUAL_SIZE;
- u32 rnd;
-
- status = efi_get_random_bytes(sizeof(rnd), (u8 *)&rnd);
- if (status == EFI_SUCCESS) {
- virtmap_base = EFI_RT_VIRTUAL_BASE +
- (((headroom >> 21) * rnd) >> (32 - 21));
- }
- }
-
- install_memreserve_table();
-
- status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
- efi_get_max_fdt_addr(dram_base),
- initrd_addr, initrd_size,
- cmdline_ptr, fdt_addr, fdt_size);
- if (status != EFI_SUCCESS)
- goto fail_free_initrd;
-
- efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
- /* not reached */
-
-fail_free_initrd:
- pr_efi_err("Failed to update FDT and exit boot services\n");
-
- efi_free(initrd_size, initrd_addr);
- efi_free(fdt_size, fdt_addr);
-
-fail_free_image:
- efi_free(image_size, image_addr);
- efi_free(reserve_size, reserve_addr);
-fail_free_cmdline:
- free_screen_info(si);
- efi_free(cmdline_size, (unsigned long)cmdline_ptr);
-fail:
- return status;
-}
-
-/*
- * efi_get_virtmap() - create a virtual mapping for the EFI memory map
- *
- * This function populates the virt_addr fields of all memory region descriptors
- * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
- * are also copied to @runtime_map, and their total count is returned in @count.
- */
-void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
- unsigned long desc_size, efi_memory_desc_t *runtime_map,
- int *count)
-{
- u64 efi_virt_base = virtmap_base;
- efi_memory_desc_t *in, *out = runtime_map;
- int l;
-
- for (l = 0; l < map_size; l += desc_size) {
- u64 paddr, size;
-
- in = (void *)memory_map + l;
- if (!(in->attribute & EFI_MEMORY_RUNTIME))
- continue;
-
- paddr = in->phys_addr;
- size = in->num_pages * EFI_PAGE_SIZE;
-
- in->virt_addr = in->phys_addr;
- if (novamap()) {
- continue;
- }
-
- /*
- * Make the mapping compatible with 64k pages: this allows
- * a 4k page size kernel to kexec a 64k page size kernel and
- * vice versa.
- */
- if (!flat_va_mapping) {
-
- paddr = round_down(in->phys_addr, SZ_64K);
- size += in->phys_addr - paddr;
-
- /*
- * Avoid wasting memory on PTEs by choosing a virtual
- * base that is compatible with section mappings if this
- * region has the appropriate size and physical
- * alignment. (Sections are 2 MB on 4k granule kernels)
- */
- if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
- efi_virt_base = round_up(efi_virt_base, SZ_2M);
- else
- efi_virt_base = round_up(efi_virt_base, SZ_64K);
-
- in->virt_addr += efi_virt_base - paddr;
- efi_virt_base += size;
- }
-
- memcpy(out, in, desc_size);
- out = (void *)out + desc_size;
- ++*count;
- }
-}
--- /dev/null
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * EFI stub implementation that is shared by arm and arm64 architectures.
+ * This should be #included by the EFI stub implementation files.
+ *
+ * Copyright (C) 2013,2014 Linaro Limited
+ * Roy Franz <roy.franz@linaro.org
+ * Copyright (C) 2013 Red Hat, Inc.
+ * Mark Salter <msalter@redhat.com>
+ */
+
+#include <linux/efi.h>
+#include <linux/libfdt.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/*
+ * This is the base address at which to start allocating virtual memory ranges
+ * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * any allocation we choose, and eliminate the risk of a conflict after kexec.
+ * The value chosen is the largest non-zero power of 2 suitable for this purpose
+ * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
+ * be mapped efficiently.
+ * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
+ * map everything below 1 GB. (512 MB is a reasonable upper bound for the
+ * entire footprint of the UEFI runtime services memory regions)
+ */
+#define EFI_RT_VIRTUAL_BASE SZ_512M
+#define EFI_RT_VIRTUAL_SIZE SZ_512M
+
+#ifdef CONFIG_ARM64
+# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64
+#else
+# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
+#endif
+
+static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
+static bool __efistub_global flat_va_mapping;
+
+static efi_system_table_t *__efistub_global sys_table;
+
+__pure efi_system_table_t *efi_system_table(void)
+{
+ return sys_table;
+}
+
+static struct screen_info *setup_graphics(void)
+{
+ efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+ efi_status_t status;
+ unsigned long size;
+ void **gop_handle = NULL;
+ struct screen_info *si = NULL;
+
+ size = 0;
+ status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+ &gop_proto, NULL, &size, gop_handle);
+ if (status == EFI_BUFFER_TOO_SMALL) {
+ si = alloc_screen_info();
+ if (!si)
+ return NULL;
+ status = efi_setup_gop(si, &gop_proto, size);
+ if (status != EFI_SUCCESS) {
+ free_screen_info(si);
+ return NULL;
+ }
+ }
+ return si;
+}
+
+void install_memreserve_table(void)
+{
+ struct linux_efi_memreserve *rsv;
+ efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
+ efi_status_t status;
+
+ status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
+ (void **)&rsv);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err("Failed to allocate memreserve entry!\n");
+ return;
+ }
+
+ rsv->next = 0;
+ rsv->size = 0;
+ atomic_set(&rsv->count, 0);
+
+ status = efi_bs_call(install_configuration_table,
+ &memreserve_table_guid, rsv);
+ if (status != EFI_SUCCESS)
+ pr_efi_err("Failed to install memreserve config table!\n");
+}
+
+static unsigned long get_dram_base(void)
+{
+ efi_status_t status;
+ unsigned long map_size, buff_size;
+ unsigned long membase = EFI_ERROR;
+ struct efi_memory_map map;
+ efi_memory_desc_t *md;
+ struct efi_boot_memmap boot_map;
+
+ boot_map.map = (efi_memory_desc_t **)&map.map;
+ boot_map.map_size = &map_size;
+ boot_map.desc_size = &map.desc_size;
+ boot_map.desc_ver = NULL;
+ boot_map.key_ptr = NULL;
+ boot_map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(&boot_map);
+ if (status != EFI_SUCCESS)
+ return membase;
+
+ map.map_end = map.map + map_size;
+
+ for_each_efi_memory_desc_in_map(&map, md) {
+ if (md->attribute & EFI_MEMORY_WB) {
+ if (membase > md->phys_addr)
+ membase = md->phys_addr;
+ }
+ }
+
+ efi_bs_call(free_pool, map.map);
+
+ return membase;
+}
+
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image);
+
+asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
+ unsigned long fdt_addr,
+ unsigned long fdt_size);
+
+/*
+ * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
+ * that is described in the PE/COFF header. Most of the code is the same
+ * for both archictectures, with the arch-specific code provided in the
+ * handle_kernel_image() function.
+ */
+efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
+{
+ efi_loaded_image_t *image;
+ efi_status_t status;
+ unsigned long image_addr;
+ unsigned long image_size = 0;
+ unsigned long dram_base;
+ /* addr/point and size pairs for memory management*/
+ unsigned long initrd_addr = 0;
+ unsigned long initrd_size = 0;
+ unsigned long fdt_addr = 0; /* Original DTB */
+ unsigned long fdt_size = 0;
+ char *cmdline_ptr = NULL;
+ int cmdline_size = 0;
+ efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
+ unsigned long reserve_addr = 0;
+ unsigned long reserve_size = 0;
+ enum efi_secureboot_mode secure_boot;
+ struct screen_info *si;
+ efi_properties_table_t *prop_tbl;
+ unsigned long max_addr;
+
+ sys_table = sys_table_arg;
+
+ /* Check if we were booted by the EFI firmware */
+ if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+ status = EFI_INVALID_PARAMETER;
+ goto fail;
+ }
+
+ status = check_platform_features();
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ /*
+ * Get a handle to the loaded image protocol. This is used to get
+ * information about the running image, such as size and the command
+ * line.
+ */
+ status = sys_table->boottime->handle_protocol(handle,
+ &loaded_image_proto, (void *)&image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err("Failed to get loaded image protocol\n");
+ goto fail;
+ }
+
+ dram_base = get_dram_base();
+ if (dram_base == EFI_ERROR) {
+ pr_efi_err("Failed to find DRAM base\n");
+ status = EFI_LOAD_ERROR;
+ goto fail;
+ }
+
+ /*
+ * Get the command line from EFI, using the LOADED_IMAGE
+ * protocol. We are going to copy the command line into the
+ * device tree, so this can be allocated anywhere.
+ */
+ cmdline_ptr = efi_convert_cmdline(image, &cmdline_size, ULONG_MAX);
+ if (!cmdline_ptr) {
+ pr_efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
+ status = EFI_OUT_OF_RESOURCES;
+ goto fail;
+ }
+
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+ IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+ cmdline_size == 0)
+ efi_parse_options(CONFIG_CMDLINE);
+
+ if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
+ efi_parse_options(cmdline_ptr);
+
+ pr_efi("Booting Linux Kernel...\n");
+
+ si = setup_graphics();
+
+ status = handle_kernel_image(&image_addr, &image_size,
+ &reserve_addr,
+ &reserve_size,
+ dram_base, image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err("Failed to relocate kernel\n");
+ goto fail_free_cmdline;
+ }
+
+ efi_retrieve_tpm2_eventlog();
+
+ /* Ask the firmware to clear memory on unclean shutdown */
+ efi_enable_reset_attack_mitigation();
+
+ secure_boot = efi_get_secureboot();
+
+ /*
+ * Unauthenticated device tree data is a security hazard, so ignore
+ * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
+ * boot is enabled if we can't determine its state.
+ */
+ if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+ secure_boot != efi_secureboot_mode_disabled) {
+ if (strstr(cmdline_ptr, "dtb="))
+ pr_efi("Ignoring DTB from command line.\n");
+ } else {
+ status = efi_load_dtb(image, &fdt_addr, &fdt_size);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err("Failed to load device tree!\n");
+ goto fail_free_image;
+ }
+ }
+
+ if (fdt_addr) {
+ pr_efi("Using DTB from command line\n");
+ } else {
+ /* Look for a device tree configuration table entry. */
+ fdt_addr = (uintptr_t)get_fdt(&fdt_size);
+ if (fdt_addr)
+ pr_efi("Using DTB from configuration table\n");
+ }
+
+ if (!fdt_addr)
+ pr_efi("Generating empty DTB\n");
+
+ if (!noinitrd()) {
+ max_addr = efi_get_max_initrd_addr(dram_base, image_addr);
+ status = efi_load_initrd_dev_path(&initrd_addr, &initrd_size,
+ max_addr);
+ if (status == EFI_SUCCESS) {
+ pr_efi("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
+ } else if (status == EFI_NOT_FOUND) {
+ status = efi_load_initrd(image, &initrd_addr, &initrd_size,
+ ULONG_MAX, max_addr);
+ if (status == EFI_SUCCESS && initrd_size > 0)
+ pr_efi("Loaded initrd from command line option\n");
+ }
+ if (status != EFI_SUCCESS)
+ pr_efi_err("Failed to load initrd!\n");
+ }
+
+ efi_random_get_seed();
+
+ /*
+ * If the NX PE data feature is enabled in the properties table, we
+ * should take care not to create a virtual mapping that changes the
+ * relative placement of runtime services code and data regions, as
+ * they may belong to the same PE/COFF executable image in memory.
+ * The easiest way to achieve that is to simply use a 1:1 mapping.
+ */
+ prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
+ flat_va_mapping = prop_tbl &&
+ (prop_tbl->memory_protection_attribute &
+ EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
+
+ /* hibernation expects the runtime regions to stay in the same place */
+ if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr() && !flat_va_mapping) {
+ /*
+ * Randomize the base of the UEFI runtime services region.
+ * Preserve the 2 MB alignment of the region by taking a
+ * shift of 21 bit positions into account when scaling
+ * the headroom value using a 32-bit random value.
+ */
+ static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
+ EFI_RT_VIRTUAL_BASE -
+ EFI_RT_VIRTUAL_SIZE;
+ u32 rnd;
+
+ status = efi_get_random_bytes(sizeof(rnd), (u8 *)&rnd);
+ if (status == EFI_SUCCESS) {
+ virtmap_base = EFI_RT_VIRTUAL_BASE +
+ (((headroom >> 21) * rnd) >> (32 - 21));
+ }
+ }
+
+ install_memreserve_table();
+
+ status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
+ efi_get_max_fdt_addr(dram_base),
+ initrd_addr, initrd_size,
+ cmdline_ptr, fdt_addr, fdt_size);
+ if (status != EFI_SUCCESS)
+ goto fail_free_initrd;
+
+ efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
+ /* not reached */
+
+fail_free_initrd:
+ pr_efi_err("Failed to update FDT and exit boot services\n");
+
+ efi_free(initrd_size, initrd_addr);
+ efi_free(fdt_size, fdt_addr);
+
+fail_free_image:
+ efi_free(image_size, image_addr);
+ efi_free(reserve_size, reserve_addr);
+fail_free_cmdline:
+ free_screen_info(si);
+ efi_free(cmdline_size, (unsigned long)cmdline_ptr);
+fail:
+ return status;
+}
+
+/*
+ * efi_get_virtmap() - create a virtual mapping for the EFI memory map
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
+ unsigned long desc_size, efi_memory_desc_t *runtime_map,
+ int *count)
+{
+ u64 efi_virt_base = virtmap_base;
+ efi_memory_desc_t *in, *out = runtime_map;
+ int l;
+
+ for (l = 0; l < map_size; l += desc_size) {
+ u64 paddr, size;
+
+ in = (void *)memory_map + l;
+ if (!(in->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ paddr = in->phys_addr;
+ size = in->num_pages * EFI_PAGE_SIZE;
+
+ in->virt_addr = in->phys_addr;
+ if (novamap()) {
+ continue;
+ }
+
+ /*
+ * Make the mapping compatible with 64k pages: this allows
+ * a 4k page size kernel to kexec a 64k page size kernel and
+ * vice versa.
+ */
+ if (!flat_va_mapping) {
+
+ paddr = round_down(in->phys_addr, SZ_64K);
+ size += in->phys_addr - paddr;
+
+ /*
+ * Avoid wasting memory on PTEs by choosing a virtual
+ * base that is compatible with section mappings if this
+ * region has the appropriate size and physical
+ * alignment. (Sections are 2 MB on 4k granule kernels)
+ */
+ if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
+ efi_virt_base = round_up(efi_virt_base, SZ_2M);
+ else
+ efi_virt_base = round_up(efi_virt_base, SZ_64K);
+
+ in->virt_addr += efi_virt_base - paddr;
+ efi_virt_base += size;
+ }
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}