--- /dev/null
- efi_setup_gop(si, &gop_proto, size);
+// 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 flat_va_mapping;
+
+const efi_system_table_t *efi_system_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;
+}
+
+static 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;
+
+ efi_system_table = sys_table_arg;
+
+ /* Check if we were booted by the EFI firmware */
+ if (efi_system_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 = efi_system_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 (!efi_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) && !efi_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 (efi_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;
+ }
+}
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