diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 419280d263d2e3f2..dd49cb9b6e3a1f1f 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -214,6 +214,11 @@ efi_status_t efi_set_virtual_address_map(unsigned long memory_map_size,
 
 /* arch specific definitions used by the stub code */
 
+struct boot_params *efi_alloc_boot_params(void);
+
+efi_status_t efi_x86_stub_common(struct boot_params *boot_params,
+				 efi_handle_t handle);
+
 #ifdef CONFIG_EFI_MIXED
 
 #define ARCH_HAS_EFISTUB_WRAPPERS
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 3abb2b357482a416..4dfbfac254614f18 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -87,7 +87,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB)	+= efi-stub.o string.o intrinsics.o systable.o \
 
 lib-$(CONFIG_ARM)		+= arm32-stub.o
 lib-$(CONFIG_ARM64)		+= arm64.o arm64-stub.o smbios.o
-lib-$(CONFIG_X86)		+= x86-stub.o
+lib-$(CONFIG_X86)		+= x86.o x86-stub.o
 lib-$(CONFIG_RISCV)		+= riscv.o riscv-stub.o
 lib-$(CONFIG_LOONGARCH)		+= loongarch.o loongarch-stub.o
 
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index a0bfd31358ba97b1..d2b75025295822c7 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -7,11 +7,9 @@
  * ----------------------------------------------------------------------- */
 
 #include <linux/efi.h>
-#include <linux/pci.h>
 #include <linux/stddef.h>
 
 #include <asm/efi.h>
-#include <asm/e820/types.h>
 #include <asm/setup.h>
 #include <asm/desc.h>
 #include <asm/boot.h>
@@ -26,192 +24,6 @@ const efi_dxe_services_table_t *efi_dxe_table;
 u32 image_offset __section(".data");
 static efi_loaded_image_t *image = NULL;
 
-static efi_status_t
-preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
-{
-	struct pci_setup_rom *rom = NULL;
-	efi_status_t status;
-	unsigned long size;
-	uint64_t romsize;
-	void *romimage;
-
-	/*
-	 * Some firmware images contain EFI function pointers at the place where
-	 * the romimage and romsize fields are supposed to be. Typically the EFI
-	 * code is mapped at high addresses, translating to an unrealistically
-	 * large romsize. The UEFI spec limits the size of option ROMs to 16
-	 * MiB so we reject any ROMs over 16 MiB in size to catch this.
-	 */
-	romimage = efi_table_attr(pci, romimage);
-	romsize = efi_table_attr(pci, romsize);
-	if (!romimage || !romsize || romsize > SZ_16M)
-		return EFI_INVALID_PARAMETER;
-
-	size = romsize + sizeof(*rom);
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)&rom);
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to allocate memory for 'rom'\n");
-		return status;
-	}
-
-	memset(rom, 0, sizeof(*rom));
-
-	rom->data.type	= SETUP_PCI;
-	rom->data.len	= size - sizeof(struct setup_data);
-	rom->data.next	= 0;
-	rom->pcilen	= pci->romsize;
-	*__rom = rom;
-
-	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
-				PCI_VENDOR_ID, 1, &rom->vendor);
-
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to read rom->vendor\n");
-		goto free_struct;
-	}
-
-	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
-				PCI_DEVICE_ID, 1, &rom->devid);
-
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to read rom->devid\n");
-		goto free_struct;
-	}
-
-	status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
-				&rom->device, &rom->function);
-
-	if (status != EFI_SUCCESS)
-		goto free_struct;
-
-	memcpy(rom->romdata, romimage, romsize);
-	return status;
-
-free_struct:
-	efi_bs_call(free_pool, rom);
-	return status;
-}
-
-/*
- * There's no way to return an informative status from this function,
- * because any analysis (and printing of error messages) needs to be
- * done directly at the EFI function call-site.
- *
- * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
- * just didn't find any PCI devices, but there's no way to tell outside
- * the context of the call.
- */
-static void setup_efi_pci(struct boot_params *params)
-{
-	efi_status_t status;
-	void **pci_handle = NULL;
-	efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
-	unsigned long size = 0;
-	struct setup_data *data;
-	efi_handle_t h;
-	int i;
-
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     &pci_proto, NULL, &size, pci_handle);
-
-	if (status == EFI_BUFFER_TOO_SMALL) {
-		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-				     (void **)&pci_handle);
-
-		if (status != EFI_SUCCESS) {
-			efi_err("Failed to allocate memory for 'pci_handle'\n");
-			return;
-		}
-
-		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-				     &pci_proto, NULL, &size, pci_handle);
-	}
-
-	if (status != EFI_SUCCESS)
-		goto free_handle;
-
-	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
-
-	while (data && data->next)
-		data = (struct setup_data *)(unsigned long)data->next;
-
-	for_each_efi_handle(h, pci_handle, size, i) {
-		efi_pci_io_protocol_t *pci = NULL;
-		struct pci_setup_rom *rom;
-
-		status = efi_bs_call(handle_protocol, h, &pci_proto,
-				     (void **)&pci);
-		if (status != EFI_SUCCESS || !pci)
-			continue;
-
-		status = preserve_pci_rom_image(pci, &rom);
-		if (status != EFI_SUCCESS)
-			continue;
-
-		if (data)
-			data->next = (unsigned long)rom;
-		else
-			params->hdr.setup_data = (unsigned long)rom;
-
-		data = (struct setup_data *)rom;
-	}
-
-free_handle:
-	efi_bs_call(free_pool, pci_handle);
-}
-
-static void retrieve_apple_device_properties(struct boot_params *boot_params)
-{
-	efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
-	struct setup_data *data, *new;
-	efi_status_t status;
-	u32 size = 0;
-	apple_properties_protocol_t *p;
-
-	status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
-	if (status != EFI_SUCCESS)
-		return;
-
-	if (efi_table_attr(p, version) != 0x10000) {
-		efi_err("Unsupported properties proto version\n");
-		return;
-	}
-
-	efi_call_proto(p, get_all, NULL, &size);
-	if (!size)
-		return;
-
-	do {
-		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
-				     size + sizeof(struct setup_data),
-				     (void **)&new);
-		if (status != EFI_SUCCESS) {
-			efi_err("Failed to allocate memory for 'properties'\n");
-			return;
-		}
-
-		status = efi_call_proto(p, get_all, new->data, &size);
-
-		if (status == EFI_BUFFER_TOO_SMALL)
-			efi_bs_call(free_pool, new);
-	} while (status == EFI_BUFFER_TOO_SMALL);
-
-	new->type = SETUP_APPLE_PROPERTIES;
-	new->len  = size;
-	new->next = 0;
-
-	data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
-	if (!data) {
-		boot_params->hdr.setup_data = (unsigned long)new;
-	} else {
-		while (data->next)
-			data = (struct setup_data *)(unsigned long)data->next;
-		data->next = (unsigned long)new;
-	}
-}
-
 static void
 adjust_memory_range_protection(unsigned long start, unsigned long size)
 {
@@ -310,134 +122,6 @@ setup_memory_protection(unsigned long image_base, unsigned long image_size)
 #endif
 }
 
-static const efi_char16_t apple[] = L"Apple";
-
-static void setup_quirks(struct boot_params *boot_params,
-			 unsigned long image_base,
-			 unsigned long image_size)
-{
-	efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
-		efi_table_attr(efi_system_table, fw_vendor);
-
-	if (!memcmp(fw_vendor, apple, sizeof(apple))) {
-		if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
-			retrieve_apple_device_properties(boot_params);
-	}
-
-	if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES))
-		setup_memory_protection(image_base, image_size);
-}
-
-/*
- * See if we have Universal Graphics Adapter (UGA) protocol
- */
-static efi_status_t
-setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
-{
-	efi_status_t status;
-	u32 width, height;
-	void **uga_handle = NULL;
-	efi_uga_draw_protocol_t *uga = NULL, *first_uga;
-	efi_handle_t handle;
-	int i;
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)&uga_handle);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     uga_proto, NULL, &size, uga_handle);
-	if (status != EFI_SUCCESS)
-		goto free_handle;
-
-	height = 0;
-	width = 0;
-
-	first_uga = NULL;
-	for_each_efi_handle(handle, uga_handle, size, i) {
-		efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
-		u32 w, h, depth, refresh;
-		void *pciio;
-
-		status = efi_bs_call(handle_protocol, handle, uga_proto,
-				     (void **)&uga);
-		if (status != EFI_SUCCESS)
-			continue;
-
-		pciio = NULL;
-		efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
-
-		status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
-		if (status == EFI_SUCCESS && (!first_uga || pciio)) {
-			width = w;
-			height = h;
-
-			/*
-			 * Once we've found a UGA supporting PCIIO,
-			 * don't bother looking any further.
-			 */
-			if (pciio)
-				break;
-
-			first_uga = uga;
-		}
-	}
-
-	if (!width && !height)
-		goto free_handle;
-
-	/* EFI framebuffer */
-	si->orig_video_isVGA	= VIDEO_TYPE_EFI;
-
-	si->lfb_depth		= 32;
-	si->lfb_width		= width;
-	si->lfb_height		= height;
-
-	si->red_size		= 8;
-	si->red_pos		= 16;
-	si->green_size		= 8;
-	si->green_pos		= 8;
-	si->blue_size		= 8;
-	si->blue_pos		= 0;
-	si->rsvd_size		= 8;
-	si->rsvd_pos		= 24;
-
-free_handle:
-	efi_bs_call(free_pool, uga_handle);
-
-	return status;
-}
-
-static void setup_graphics(struct boot_params *boot_params)
-{
-	efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-	struct screen_info *si;
-	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
-	efi_status_t status;
-	unsigned long size;
-	void **gop_handle = NULL;
-	void **uga_handle = NULL;
-
-	si = &boot_params->screen_info;
-	memset(si, 0, sizeof(*si));
-
-	size = 0;
-	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-			     &graphics_proto, NULL, &size, gop_handle);
-	if (status == EFI_BUFFER_TOO_SMALL)
-		status = efi_setup_gop(si, &graphics_proto, size);
-
-	if (status != EFI_SUCCESS) {
-		size = 0;
-		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
-				     &uga_proto, NULL, &size, uga_handle);
-		if (status == EFI_BUFFER_TOO_SMALL)
-			setup_uga(si, &uga_proto, size);
-	}
-}
-
-
 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 {
 	efi_bs_call(exit, handle, status, 0, NULL);
@@ -480,14 +164,9 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	image_base = efi_table_attr(image, image_base);
 	image_offset = (void *)startup_32 - image_base;
 
-	status = efi_allocate_pages(sizeof(struct boot_params),
-				    (unsigned long *)&boot_params, ULONG_MAX);
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to allocate lowmem for boot params\n");
-		efi_exit(handle, status);
-	}
-
-	memset(boot_params, 0x0, sizeof(struct boot_params));
+	boot_params = efi_alloc_boot_params();
+	if (!boot_params)
+		efi_exit(handle, EFI_OUT_OF_RESOURCES);
 
 	hdr = &boot_params->hdr;
 
@@ -495,14 +174,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	memcpy(&hdr->jump, image_base + 512,
 	       sizeof(struct setup_header) - offsetof(struct setup_header, jump));
 
-	/*
-	 * Fill out some of the header fields ourselves because the
-	 * EFI firmware loader doesn't load the first sector.
-	 */
-	hdr->root_flags	= 1;
-	hdr->vid_mode	= 0xffff;
-	hdr->boot_flag	= 0xAA55;
-
 	hdr->type_of_loader = 0x21;
 
 	/* Convert unicode cmdline to ascii */
@@ -532,234 +203,6 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	efi_exit(handle, status);
 }
 
-static void add_e820ext(struct boot_params *params,
-			struct setup_data *e820ext, u32 nr_entries)
-{
-	struct setup_data *data;
-
-	e820ext->type = SETUP_E820_EXT;
-	e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
-	e820ext->next = 0;
-
-	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
-
-	while (data && data->next)
-		data = (struct setup_data *)(unsigned long)data->next;
-
-	if (data)
-		data->next = (unsigned long)e820ext;
-	else
-		params->hdr.setup_data = (unsigned long)e820ext;
-}
-
-static efi_status_t
-setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
-{
-	struct boot_e820_entry *entry = params->e820_table;
-	struct efi_info *efi = &params->efi_info;
-	struct boot_e820_entry *prev = NULL;
-	u32 nr_entries;
-	u32 nr_desc;
-	int i;
-
-	nr_entries = 0;
-	nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
-
-	for (i = 0; i < nr_desc; i++) {
-		efi_memory_desc_t *d;
-		unsigned int e820_type = 0;
-		unsigned long m = efi->efi_memmap;
-
-#ifdef CONFIG_X86_64
-		m |= (u64)efi->efi_memmap_hi << 32;
-#endif
-
-		d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
-		switch (d->type) {
-		case EFI_RESERVED_TYPE:
-		case EFI_RUNTIME_SERVICES_CODE:
-		case EFI_RUNTIME_SERVICES_DATA:
-		case EFI_MEMORY_MAPPED_IO:
-		case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
-		case EFI_PAL_CODE:
-			e820_type = E820_TYPE_RESERVED;
-			break;
-
-		case EFI_UNUSABLE_MEMORY:
-			e820_type = E820_TYPE_UNUSABLE;
-			break;
-
-		case EFI_ACPI_RECLAIM_MEMORY:
-			e820_type = E820_TYPE_ACPI;
-			break;
-
-		case EFI_LOADER_CODE:
-		case EFI_LOADER_DATA:
-		case EFI_BOOT_SERVICES_CODE:
-		case EFI_BOOT_SERVICES_DATA:
-		case EFI_CONVENTIONAL_MEMORY:
-			if (efi_soft_reserve_enabled() &&
-			    (d->attribute & EFI_MEMORY_SP))
-				e820_type = E820_TYPE_SOFT_RESERVED;
-			else
-				e820_type = E820_TYPE_RAM;
-			break;
-
-		case EFI_ACPI_MEMORY_NVS:
-			e820_type = E820_TYPE_NVS;
-			break;
-
-		case EFI_PERSISTENT_MEMORY:
-			e820_type = E820_TYPE_PMEM;
-			break;
-
-		default:
-			continue;
-		}
-
-		/* Merge adjacent mappings */
-		if (prev && prev->type == e820_type &&
-		    (prev->addr + prev->size) == d->phys_addr) {
-			prev->size += d->num_pages << 12;
-			continue;
-		}
-
-		if (nr_entries == ARRAY_SIZE(params->e820_table)) {
-			u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
-				   sizeof(struct setup_data);
-
-			if (!e820ext || e820ext_size < need)
-				return EFI_BUFFER_TOO_SMALL;
-
-			/* boot_params map full, switch to e820 extended */
-			entry = (struct boot_e820_entry *)e820ext->data;
-		}
-
-		entry->addr = d->phys_addr;
-		entry->size = d->num_pages << PAGE_SHIFT;
-		entry->type = e820_type;
-		prev = entry++;
-		nr_entries++;
-	}
-
-	if (nr_entries > ARRAY_SIZE(params->e820_table)) {
-		u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
-
-		add_e820ext(params, e820ext, nr_e820ext);
-		nr_entries -= nr_e820ext;
-	}
-
-	params->e820_entries = (u8)nr_entries;
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
-				  u32 *e820ext_size)
-{
-	efi_status_t status;
-	unsigned long size;
-
-	size = sizeof(struct setup_data) +
-		sizeof(struct e820_entry) * nr_desc;
-
-	if (*e820ext) {
-		efi_bs_call(free_pool, *e820ext);
-		*e820ext = NULL;
-		*e820ext_size = 0;
-	}
-
-	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
-			     (void **)e820ext);
-	if (status == EFI_SUCCESS)
-		*e820ext_size = size;
-
-	return status;
-}
-
-static efi_status_t allocate_e820(struct boot_params *params,
-				  struct setup_data **e820ext,
-				  u32 *e820ext_size)
-{
-	unsigned long map_size, desc_size, map_key;
-	efi_status_t status;
-	__u32 nr_desc, desc_version;
-
-	/* Only need the size of the mem map and size of each mem descriptor */
-	map_size = 0;
-	status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
-			     &desc_size, &desc_version);
-	if (status != EFI_BUFFER_TOO_SMALL)
-		return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
-
-	nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
-
-	if (nr_desc > ARRAY_SIZE(params->e820_table)) {
-		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
-
-		status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
-		if (status != EFI_SUCCESS)
-			return status;
-	}
-
-	return EFI_SUCCESS;
-}
-
-struct exit_boot_struct {
-	struct boot_params	*boot_params;
-	struct efi_info		*efi;
-};
-
-static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
-				   void *priv)
-{
-	const char *signature;
-	struct exit_boot_struct *p = priv;
-
-	signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
-				   : EFI32_LOADER_SIGNATURE;
-	memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
-
-	efi_set_u64_split((unsigned long)efi_system_table,
-			  &p->efi->efi_systab, &p->efi->efi_systab_hi);
-	p->efi->efi_memdesc_size	= map->desc_size;
-	p->efi->efi_memdesc_version	= map->desc_ver;
-	efi_set_u64_split((unsigned long)map->map,
-			  &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
-	p->efi->efi_memmap_size		= map->map_size;
-
-	return EFI_SUCCESS;
-}
-
-static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
-{
-	struct setup_data *e820ext = NULL;
-	__u32 e820ext_size = 0;
-	efi_status_t status;
-	struct exit_boot_struct priv;
-
-	priv.boot_params	= boot_params;
-	priv.efi		= &boot_params->efi_info;
-
-	status = allocate_e820(boot_params, &e820ext, &e820ext_size);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	/* Might as well exit boot services now */
-	status = efi_exit_boot_services(handle, &priv, exit_boot_func);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	/* Historic? */
-	boot_params->alt_mem_k	= 32 * 1024;
-
-	status = setup_e820(boot_params, e820ext, e820ext_size);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	return EFI_SUCCESS;
-}
-
 /*
  * On success, we return the address of startup_32, which has potentially been
  * relocated by efi_relocate_kernel.
@@ -878,32 +321,12 @@ asmlinkage unsigned long efi_main(efi_handle_t handle,
 				  &boot_params->ext_ramdisk_size);
 	}
 
+	if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES))
+		setup_memory_protection(bzimage_addr, buffer_end - buffer_start);
 
-	/*
-	 * If the boot loader gave us a value for secure_boot then we use that,
-	 * otherwise we ask the BIOS.
-	 */
-	if (boot_params->secure_boot == efi_secureboot_mode_unset)
-		boot_params->secure_boot = efi_get_secureboot();
-
-	/* Ask the firmware to clear memory on unclean shutdown */
-	efi_enable_reset_attack_mitigation();
-
-	efi_random_get_seed();
-
-	efi_retrieve_tpm2_eventlog();
-
-	setup_graphics(boot_params);
-
-	setup_efi_pci(boot_params);
-
-	setup_quirks(boot_params, bzimage_addr, buffer_end - buffer_start);
-
-	status = exit_boot(boot_params, handle);
-	if (status != EFI_SUCCESS) {
-		efi_err("exit_boot() failed!\n");
+	status = efi_x86_stub_common(boot_params, handle);
+	if (status != EFI_SUCCESS)
 		goto fail;
-	}
 
 	return bzimage_addr;
 fail:
diff --git a/drivers/firmware/efi/libstub/x86.c b/drivers/firmware/efi/libstub/x86.c
new file mode 100644
index 0000000000000000..fcaf69eace751f17
--- /dev/null
+++ b/drivers/firmware/efi/libstub/x86.c
@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 2011 Intel Corporation; author Matt Fleming
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <linux/efi.h>
+#include <linux/pci.h>
+#include <linux/stddef.h>
+
+#include <asm/efi.h>
+#include <asm/e820/types.h>
+#include <asm/setup.h>
+#include <asm/desc.h>
+#include <asm/boot.h>
+
+#include "efistub.h"
+
+static void add_e820ext(struct boot_params *params,
+			struct setup_data *e820ext, u32 nr_entries)
+{
+	struct setup_data *data;
+
+	e820ext->type = SETUP_E820_EXT;
+	e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
+	e820ext->next = 0;
+
+	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+	while (data && data->next)
+		data = (struct setup_data *)(unsigned long)data->next;
+
+	if (data)
+		data->next = (unsigned long)e820ext;
+	else
+		params->hdr.setup_data = (unsigned long)e820ext;
+}
+
+static efi_status_t
+setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
+{
+	struct boot_e820_entry *entry = params->e820_table;
+	struct efi_info *efi = &params->efi_info;
+	struct boot_e820_entry *prev = NULL;
+	u32 nr_entries;
+	u32 nr_desc;
+	int i;
+
+	nr_entries = 0;
+	nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
+
+	for (i = 0; i < nr_desc; i++) {
+		efi_memory_desc_t *d;
+		unsigned int e820_type = 0;
+		unsigned long m = efi->efi_memmap;
+
+#ifdef CONFIG_X86_64
+		m |= (u64)efi->efi_memmap_hi << 32;
+#endif
+
+		d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
+		switch (d->type) {
+		case EFI_RESERVED_TYPE:
+		case EFI_RUNTIME_SERVICES_CODE:
+		case EFI_RUNTIME_SERVICES_DATA:
+		case EFI_MEMORY_MAPPED_IO:
+		case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
+		case EFI_PAL_CODE:
+			e820_type = E820_TYPE_RESERVED;
+			break;
+
+		case EFI_UNUSABLE_MEMORY:
+			e820_type = E820_TYPE_UNUSABLE;
+			break;
+
+		case EFI_ACPI_RECLAIM_MEMORY:
+			e820_type = E820_TYPE_ACPI;
+			break;
+
+		case EFI_LOADER_CODE:
+		case EFI_LOADER_DATA:
+		case EFI_BOOT_SERVICES_CODE:
+		case EFI_BOOT_SERVICES_DATA:
+		case EFI_CONVENTIONAL_MEMORY:
+			if (efi_soft_reserve_enabled() &&
+			    (d->attribute & EFI_MEMORY_SP))
+				e820_type = E820_TYPE_SOFT_RESERVED;
+			else
+				e820_type = E820_TYPE_RAM;
+			break;
+
+		case EFI_ACPI_MEMORY_NVS:
+			e820_type = E820_TYPE_NVS;
+			break;
+
+		case EFI_PERSISTENT_MEMORY:
+			e820_type = E820_TYPE_PMEM;
+			break;
+
+		default:
+			continue;
+		}
+
+		/* Merge adjacent mappings */
+		if (prev && prev->type == e820_type &&
+		    (prev->addr + prev->size) == d->phys_addr) {
+			prev->size += d->num_pages << 12;
+			continue;
+		}
+
+		if (nr_entries == ARRAY_SIZE(params->e820_table)) {
+			u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
+				   sizeof(struct setup_data);
+
+			if (!e820ext || e820ext_size < need)
+				return EFI_BUFFER_TOO_SMALL;
+
+			/* boot_params map full, switch to e820 extended */
+			entry = (struct boot_e820_entry *)e820ext->data;
+		}
+
+		entry->addr = d->phys_addr;
+		entry->size = d->num_pages << PAGE_SHIFT;
+		entry->type = e820_type;
+		prev = entry++;
+		nr_entries++;
+	}
+
+	if (nr_entries > ARRAY_SIZE(params->e820_table)) {
+		u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
+
+		add_e820ext(params, e820ext, nr_e820ext);
+		nr_entries -= nr_e820ext;
+	}
+
+	params->e820_entries = (u8)nr_entries;
+
+	return EFI_SUCCESS;
+}
+
+static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
+				  u32 *e820ext_size)
+{
+	efi_status_t status;
+	unsigned long size;
+
+	size = sizeof(struct setup_data) +
+		sizeof(struct e820_entry) * nr_desc;
+
+	if (*e820ext) {
+		efi_bs_call(free_pool, *e820ext);
+		*e820ext = NULL;
+		*e820ext_size = 0;
+	}
+
+	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+			     (void **)e820ext);
+	if (status == EFI_SUCCESS)
+		*e820ext_size = size;
+
+	return status;
+}
+
+static efi_status_t allocate_e820(struct boot_params *params,
+				  struct setup_data **e820ext,
+				  u32 *e820ext_size)
+{
+	unsigned long map_size, desc_size, map_key;
+	efi_status_t status;
+	__u32 nr_desc, desc_version;
+
+	/* Only need the size of the mem map and size of each mem descriptor */
+	map_size = 0;
+	status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
+			     &desc_size, &desc_version);
+	if (status != EFI_BUFFER_TOO_SMALL)
+		return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
+
+	nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
+
+	if (nr_desc > ARRAY_SIZE(params->e820_table)) {
+		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
+
+		status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
+		if (status != EFI_SUCCESS)
+			return status;
+	}
+
+	return EFI_SUCCESS;
+}
+
+struct exit_boot_struct {
+	struct boot_params	*boot_params;
+	struct efi_info		*efi;
+};
+
+static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
+				   void *priv)
+{
+	const char *signature;
+	struct exit_boot_struct *p = priv;
+
+	signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
+				   : EFI32_LOADER_SIGNATURE;
+	memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
+
+	efi_set_u64_split((unsigned long)efi_system_table,
+			  &p->efi->efi_systab, &p->efi->efi_systab_hi);
+	p->efi->efi_memdesc_size	= map->desc_size;
+	p->efi->efi_memdesc_version	= map->desc_ver;
+	efi_set_u64_split((unsigned long)map->map,
+			  &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
+	p->efi->efi_memmap_size		= map->map_size;
+
+	return EFI_SUCCESS;
+}
+
+static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
+{
+	struct setup_data *e820ext = NULL;
+	__u32 e820ext_size = 0;
+	efi_status_t status;
+	struct exit_boot_struct priv;
+
+	priv.boot_params	= boot_params;
+	priv.efi		= &boot_params->efi_info;
+
+	status = allocate_e820(boot_params, &e820ext, &e820ext_size);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	/* Might as well exit boot services now */
+	status = efi_exit_boot_services(handle, &priv, exit_boot_func);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	/* Historic? */
+	boot_params->alt_mem_k	= 32 * 1024;
+
+	status = setup_e820(boot_params, e820ext, e820ext_size);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	return EFI_SUCCESS;
+}
+
+static efi_status_t
+preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
+{
+	struct pci_setup_rom *rom = NULL;
+	efi_status_t status;
+	unsigned long size;
+	uint64_t romsize;
+	void *romimage;
+
+	/*
+	 * Some firmware images contain EFI function pointers at the place where
+	 * the romimage and romsize fields are supposed to be. Typically the EFI
+	 * code is mapped at high addresses, translating to an unrealistically
+	 * large romsize. The UEFI spec limits the size of option ROMs to 16
+	 * MiB so we reject any ROMs over 16 MiB in size to catch this.
+	 */
+	romimage = efi_table_attr(pci, romimage);
+	romsize = efi_table_attr(pci, romsize);
+	if (!romimage || !romsize || romsize > SZ_16M)
+		return EFI_INVALID_PARAMETER;
+
+	size = romsize + sizeof(*rom);
+
+	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+			     (void **)&rom);
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to allocate memory for 'rom'\n");
+		return status;
+	}
+
+	memset(rom, 0, sizeof(*rom));
+
+	rom->data.type	= SETUP_PCI;
+	rom->data.len	= size - sizeof(struct setup_data);
+	rom->data.next	= 0;
+	rom->pcilen	= pci->romsize;
+	*__rom = rom;
+
+	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
+				PCI_VENDOR_ID, 1, &rom->vendor);
+
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to read rom->vendor\n");
+		goto free_struct;
+	}
+
+	status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
+				PCI_DEVICE_ID, 1, &rom->devid);
+
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to read rom->devid\n");
+		goto free_struct;
+	}
+
+	status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
+				&rom->device, &rom->function);
+
+	if (status != EFI_SUCCESS)
+		goto free_struct;
+
+	memcpy(rom->romdata, romimage, romsize);
+	return status;
+
+free_struct:
+	efi_bs_call(free_pool, rom);
+	return status;
+}
+
+/*
+ * There's no way to return an informative status from this function,
+ * because any analysis (and printing of error messages) needs to be
+ * done directly at the EFI function call-site.
+ *
+ * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
+ * just didn't find any PCI devices, but there's no way to tell outside
+ * the context of the call.
+ */
+static void setup_efi_pci(struct boot_params *params)
+{
+	efi_status_t status;
+	void **pci_handle = NULL;
+	efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
+	unsigned long size = 0;
+	struct setup_data *data;
+	efi_handle_t h;
+	int i;
+
+	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+			     &pci_proto, NULL, &size, pci_handle);
+
+	if (status == EFI_BUFFER_TOO_SMALL) {
+		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+				     (void **)&pci_handle);
+
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to allocate memory for 'pci_handle'\n");
+			return;
+		}
+
+		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+				     &pci_proto, NULL, &size, pci_handle);
+	}
+
+	if (status != EFI_SUCCESS)
+		goto free_handle;
+
+	data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
+
+	while (data && data->next)
+		data = (struct setup_data *)(unsigned long)data->next;
+
+	for_each_efi_handle(h, pci_handle, size, i) {
+		efi_pci_io_protocol_t *pci = NULL;
+		struct pci_setup_rom *rom;
+
+		status = efi_bs_call(handle_protocol, h, &pci_proto,
+				     (void **)&pci);
+		if (status != EFI_SUCCESS || !pci)
+			continue;
+
+		status = preserve_pci_rom_image(pci, &rom);
+		if (status != EFI_SUCCESS)
+			continue;
+
+		if (data)
+			data->next = (unsigned long)rom;
+		else
+			params->hdr.setup_data = (unsigned long)rom;
+
+		data = (struct setup_data *)rom;
+	}
+
+free_handle:
+	efi_bs_call(free_pool, pci_handle);
+}
+
+/*
+ * See if we have Universal Graphics Adapter (UGA) protocol
+ */
+static efi_status_t
+setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
+{
+	efi_status_t status;
+	u32 width, height;
+	void **uga_handle = NULL;
+	efi_uga_draw_protocol_t *uga = NULL, *first_uga;
+	efi_handle_t handle;
+	int i;
+
+	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+			     (void **)&uga_handle);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+			     uga_proto, NULL, &size, uga_handle);
+	if (status != EFI_SUCCESS)
+		goto free_handle;
+
+	height = 0;
+	width = 0;
+
+	first_uga = NULL;
+	for_each_efi_handle(handle, uga_handle, size, i) {
+		efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
+		u32 w, h, depth, refresh;
+		void *pciio;
+
+		status = efi_bs_call(handle_protocol, handle, uga_proto,
+				     (void **)&uga);
+		if (status != EFI_SUCCESS)
+			continue;
+
+		pciio = NULL;
+		efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
+
+		status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
+		if (status == EFI_SUCCESS && (!first_uga || pciio)) {
+			width = w;
+			height = h;
+
+			/*
+			 * Once we've found a UGA supporting PCIIO,
+			 * don't bother looking any further.
+			 */
+			if (pciio)
+				break;
+
+			first_uga = uga;
+		}
+	}
+
+	if (!width && !height)
+		goto free_handle;
+
+	/* EFI framebuffer */
+	si->orig_video_isVGA	= VIDEO_TYPE_EFI;
+
+	si->lfb_depth		= 32;
+	si->lfb_width		= width;
+	si->lfb_height		= height;
+
+	si->red_size		= 8;
+	si->red_pos		= 16;
+	si->green_size		= 8;
+	si->green_pos		= 8;
+	si->blue_size		= 8;
+	si->blue_pos		= 0;
+	si->rsvd_size		= 8;
+	si->rsvd_pos		= 24;
+
+free_handle:
+	efi_bs_call(free_pool, uga_handle);
+
+	return status;
+}
+
+static void setup_graphics(struct boot_params *boot_params)
+{
+	efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+	struct screen_info *si;
+	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
+	efi_status_t status;
+	unsigned long size;
+	void **gop_handle = NULL;
+	void **uga_handle = NULL;
+
+	si = &boot_params->screen_info;
+	memset(si, 0, sizeof(*si));
+
+	size = 0;
+	status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+			     &graphics_proto, NULL, &size, gop_handle);
+	if (status == EFI_BUFFER_TOO_SMALL)
+		status = efi_setup_gop(si, &graphics_proto, size);
+
+	if (status != EFI_SUCCESS) {
+		size = 0;
+		status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+				     &uga_proto, NULL, &size, uga_handle);
+		if (status == EFI_BUFFER_TOO_SMALL)
+			setup_uga(si, &uga_proto, size);
+	}
+}
+
+static void retrieve_apple_device_properties(struct boot_params *boot_params)
+{
+	efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
+	struct setup_data *data, *new;
+	efi_status_t status;
+	u32 size = 0;
+	apple_properties_protocol_t *p;
+
+	status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
+	if (status != EFI_SUCCESS)
+		return;
+
+	if (efi_table_attr(p, version) != 0x10000) {
+		efi_err("Unsupported properties proto version\n");
+		return;
+	}
+
+	efi_call_proto(p, get_all, NULL, &size);
+	if (!size)
+		return;
+
+	do {
+		status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
+				     size + sizeof(struct setup_data),
+				     (void **)&new);
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to allocate memory for 'properties'\n");
+			return;
+		}
+
+		status = efi_call_proto(p, get_all, new->data, &size);
+
+		if (status == EFI_BUFFER_TOO_SMALL)
+			efi_bs_call(free_pool, new);
+	} while (status == EFI_BUFFER_TOO_SMALL);
+
+	new->type = SETUP_APPLE_PROPERTIES;
+	new->len  = size;
+	new->next = 0;
+
+	data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
+	if (!data) {
+		boot_params->hdr.setup_data = (unsigned long)new;
+	} else {
+		while (data->next)
+			data = (struct setup_data *)(unsigned long)data->next;
+		data->next = (unsigned long)new;
+	}
+}
+
+static const efi_char16_t apple[] = L"Apple";
+
+static void setup_quirks(struct boot_params *boot_params)
+{
+	efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
+		efi_table_attr(efi_system_table, fw_vendor);
+
+	if (!memcmp(fw_vendor, apple, sizeof(apple))) {
+		if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
+			retrieve_apple_device_properties(boot_params);
+	}
+}
+
+efi_status_t efi_x86_stub_common(struct boot_params *boot_params,
+				 efi_handle_t handle)
+{
+	efi_status_t status;
+
+	/*
+	 * If the boot loader gave us a value for secure_boot then we use that,
+	 * otherwise we ask the BIOS.
+	 */
+	if (boot_params->secure_boot == efi_secureboot_mode_unset)
+		boot_params->secure_boot = efi_get_secureboot();
+
+	/* Ask the firmware to clear memory on unclean shutdown */
+	efi_enable_reset_attack_mitigation();
+
+	efi_random_get_seed();
+
+	efi_retrieve_tpm2_eventlog();
+
+	setup_graphics(boot_params);
+
+	setup_efi_pci(boot_params);
+
+	setup_quirks(boot_params);
+
+	status = exit_boot(boot_params, handle);
+	if (status != EFI_SUCCESS)
+		efi_err("exit_boot() failed!\n");
+
+	return status;
+}
+
+struct boot_params *efi_alloc_boot_params(void)
+{
+	struct boot_params *boot_params;
+	efi_status_t status;
+
+	status = efi_allocate_pages(sizeof(struct boot_params),
+				    (unsigned long *)&boot_params, ULONG_MAX);
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to allocate lowmem for boot params\n");
+		return NULL;
+	}
+
+	memset(boot_params, 0x0, sizeof(struct boot_params));
+
+	/*
+	 * Fill out some of the header fields ourselves because the
+	 * EFI firmware loader doesn't load the first sector.
+	 */
+	boot_params->hdr.root_flags	= 1;
+	boot_params->hdr.vid_mode	= 0xffff;
+	boot_params->hdr.boot_flag	= 0xAA55;
+
+	return boot_params;
+}
