Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 934 insertions, 0 deletions

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
new file mode 100644
index 000000000..544ac4faf
--- /dev/null
+++ b/arch/x86/boot/compressed/eboot.c
@@ -0,0 +1,934 @@
+
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 2011 Intel Corporation; author Matt Fleming
+ *
+ *   This file is part of the Linux kernel, and is made available under
+ *   the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <linux/efi.h>
+#include <linux/pci.h>
+
+#include <asm/efi.h>
+#include <asm/e820/types.h>
+#include <asm/setup.h>
+#include <asm/desc.h>
+
+#include "../string.h"
+#include "eboot.h"
+
+static efi_system_table_t *sys_table;
+
+static struct efi_config *efi_early;
+
+__pure const struct efi_config *__efi_early(void)
+{
+	return efi_early;
+}
+
+#define BOOT_SERVICES(bits)						\
+static void setup_boot_services##bits(struct efi_config *c)		\
+{									\
+	efi_system_table_##bits##_t *table;				\
+									\
+	table = (typeof(table))sys_table;				\
+									\
+	c->runtime_services	= table->runtime;			\
+	c->boot_services	= table->boottime;			\
+	c->text_output		= table->con_out;			\
+}
+BOOT_SERVICES(32);
+BOOT_SERVICES(64);
+
+void efi_char16_printk(efi_system_table_t *table, efi_char16_t *str)
+{
+	efi_call_proto(efi_simple_text_output_protocol, output_string,
+		       efi_early->text_output, str);
+}
+
+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 = (void *)(unsigned long)efi_table_attr(efi_pci_io_protocol,
+							 romimage, pci);
+	romsize = efi_table_attr(efi_pci_io_protocol, romsize, pci);
+	if (!romimage || !romsize || romsize > SZ_16M)
+		return EFI_INVALID_PARAMETER;
+
+	size = romsize + sizeof(*rom);
+
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "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(efi_pci_io_protocol, pci.read, pci,
+				EfiPciIoWidthUint16, PCI_VENDOR_ID, 1,
+				&rom->vendor);
+
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->vendor\n");
+		goto free_struct;
+	}
+
+	status = efi_call_proto(efi_pci_io_protocol, pci.read, pci,
+				EfiPciIoWidthUint16, PCI_DEVICE_ID, 1,
+				&rom->devid);
+
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to read rom->devid\n");
+		goto free_struct;
+	}
+
+	status = efi_call_proto(efi_pci_io_protocol, get_location, pci,
+				&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_call_early(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;
+	unsigned long nr_pci;
+	struct setup_data *data;
+	int i;
+
+	status = efi_call_early(locate_handle,
+				EFI_LOCATE_BY_PROTOCOL,
+				&pci_proto, NULL, &size, pci_handle);
+
+	if (status == EFI_BUFFER_TOO_SMALL) {
+		status = efi_call_early(allocate_pool,
+					EFI_LOADER_DATA,
+					size, (void **)&pci_handle);
+
+		if (status != EFI_SUCCESS) {
+			efi_printk(sys_table, "Failed to allocate memory for 'pci_handle'\n");
+			return;
+		}
+
+		status = efi_call_early(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;
+
+	nr_pci = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
+	for (i = 0; i < nr_pci; i++) {
+		efi_pci_io_protocol_t *pci = NULL;
+		struct pci_setup_rom *rom;
+
+		status = efi_call_early(handle_protocol,
+					efi_is_64bit() ? ((u64 *)pci_handle)[i]
+						       : ((u32 *)pci_handle)[i],
+					&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_call_early(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;
+	void *p;
+
+	status = efi_call_early(locate_protocol, &guid, NULL, &p);
+	if (status != EFI_SUCCESS)
+		return;
+
+	if (efi_table_attr(apple_properties_protocol, version, p) != 0x10000) {
+		efi_printk(sys_table, "Unsupported properties proto version\n");
+		return;
+	}
+
+	efi_call_proto(apple_properties_protocol, get_all, p, NULL, &size);
+	if (!size)
+		return;
+
+	do {
+		status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+					size + sizeof(struct setup_data), &new);
+		if (status != EFI_SUCCESS) {
+			efi_printk(sys_table, "Failed to allocate memory for 'properties'\n");
+			return;
+		}
+
+		status = efi_call_proto(apple_properties_protocol, get_all, p,
+					new->data, &size);
+
+		if (status == EFI_BUFFER_TOO_SMALL)
+			efi_call_early(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, sys_table);
+
+	if (!memcmp(fw_vendor, apple, sizeof(apple))) {
+		if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
+			retrieve_apple_device_properties(boot_params);
+	}
+}
+
+/*
+ * 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;
+	unsigned long nr_ugas;
+	int i;
+
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+				size, (void **)&uga_handle);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	status = efi_call_early(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;
+	nr_ugas = size / (efi_is_64bit() ? sizeof(u64) : sizeof(u32));
+	for (i = 0; i < nr_ugas; i++) {
+		efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
+		u32 w, h, depth, refresh;
+		void *pciio;
+		unsigned long handle = efi_is_64bit() ? ((u64 *)uga_handle)[i]
+						      : ((u32 *)uga_handle)[i];
+
+		status = efi_call_early(handle_protocol, handle,
+					uga_proto, (void **)&uga);
+		if (status != EFI_SUCCESS)
+			continue;
+
+		pciio = NULL;
+		efi_call_early(handle_protocol, handle, &pciio_proto, &pciio);
+
+		status = efi_call_proto(efi_uga_draw_protocol, get_mode, uga,
+					&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_call_early(free_pool, uga_handle);
+
+	return status;
+}
+
+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_call_early(locate_handle,
+				EFI_LOCATE_BY_PROTOCOL,
+				&graphics_proto, NULL, &size, gop_handle);
+	if (status == EFI_BUFFER_TOO_SMALL)
+		status = efi_setup_gop(NULL, si, &graphics_proto, size);
+
+	if (status != EFI_SUCCESS) {
+		size = 0;
+		status = efi_call_early(locate_handle,
+					EFI_LOCATE_BY_PROTOCOL,
+					&uga_proto, NULL, &size, uga_handle);
+		if (status == EFI_BUFFER_TOO_SMALL)
+			setup_uga(si, &uga_proto, size);
+	}
+}
+
+/*
+ * Because the x86 boot code expects to be passed a boot_params we
+ * need to create one ourselves (usually the bootloader would create
+ * one for us).
+ *
+ * The caller is responsible for filling out ->code32_start in the
+ * returned boot_params.
+ */
+struct boot_params *make_boot_params(struct efi_config *c)
+{
+	struct boot_params *boot_params;
+	struct apm_bios_info *bi;
+	struct setup_header *hdr;
+	efi_loaded_image_t *image;
+	void *options, *handle;
+	efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
+	int options_size = 0;
+	efi_status_t status;
+	char *cmdline_ptr;
+	u16 *s2;
+	u8 *s1;
+	int i;
+	unsigned long ramdisk_addr;
+	unsigned long ramdisk_size;
+
+	efi_early = c;
+	sys_table = (efi_system_table_t *)(unsigned long)efi_early->table;
+	handle = (void *)(unsigned long)efi_early->image_handle;
+
+	/* Check if we were booted by the EFI firmware */
+	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+		return NULL;
+
+	if (efi_is_64bit())
+		setup_boot_services64(efi_early);
+	else
+		setup_boot_services32(efi_early);
+
+	status = efi_call_early(handle_protocol, handle,
+				&proto, (void *)&image);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
+		return NULL;
+	}
+
+	status = efi_low_alloc(sys_table, 0x4000, 1,
+			       (unsigned long *)&boot_params);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to allocate lowmem for boot params\n");
+		return NULL;
+	}
+
+	memset(boot_params, 0x0, 0x4000);
+
+	hdr = &boot_params->hdr;
+	bi = &boot_params->apm_bios_info;
+
+	/* Copy the second sector to boot_params */
+	memcpy(&hdr->jump, image->image_base + 512, 512);
+
+	/*
+	 * 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 */
+	cmdline_ptr = efi_convert_cmdline(sys_table, image, &options_size);
+	if (!cmdline_ptr)
+		goto fail;
+
+	hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
+	/* Fill in upper bits of command line address, NOP on 32 bit  */
+	boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
+
+	hdr->ramdisk_image = 0;
+	hdr->ramdisk_size = 0;
+
+	/* Clear APM BIOS info */
+	memset(bi, 0, sizeof(*bi));
+
+	status = efi_parse_options(cmdline_ptr);
+	if (status != EFI_SUCCESS)
+		goto fail2;
+
+	status = handle_cmdline_files(sys_table, image,
+				      (char *)(unsigned long)hdr->cmd_line_ptr,
+				      "initrd=", hdr->initrd_addr_max,
+				      &ramdisk_addr, &ramdisk_size);
+
+	if (status != EFI_SUCCESS &&
+	    hdr->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G) {
+		efi_printk(sys_table, "Trying to load files to higher address\n");
+		status = handle_cmdline_files(sys_table, image,
+				      (char *)(unsigned long)hdr->cmd_line_ptr,
+				      "initrd=", -1UL,
+				      &ramdisk_addr, &ramdisk_size);
+	}
+
+	if (status != EFI_SUCCESS)
+		goto fail2;
+	hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
+	hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
+	boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
+	boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
+
+	return boot_params;
+
+fail2:
+	efi_free(sys_table, options_size, hdr->cmd_line_ptr);
+fail:
+	efi_free(sys_table, 0x4000, (unsigned long)boot_params);
+
+	return NULL;
+}
+
+static void add_e820ext(struct boot_params *params,
+			struct setup_data *e820ext, u32 nr_entries)
+{
+	struct setup_data *data;
+	efi_status_t status;
+	unsigned long size;
+
+	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:
+			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_call_early(free_pool, *e820ext);
+		*e820ext = NULL;
+		*e820ext_size = 0;
+	}
+
+	status = efi_call_early(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, buff_size;
+	struct efi_boot_memmap boot_map;
+	efi_memory_desc_t *map;
+	efi_status_t status;
+	__u32 nr_desc;
+
+	boot_map.map		= &map;
+	boot_map.map_size	= &map_size;
+	boot_map.desc_size	= &desc_size;
+	boot_map.desc_ver	= NULL;
+	boot_map.key_ptr	= NULL;
+	boot_map.buff_size	= &buff_size;
+
+	status = efi_get_memory_map(sys_table, &boot_map);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	nr_desc = buff_size / desc_size;
+
+	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(efi_system_table_t *sys_table_arg,
+				   struct efi_boot_memmap *map,
+				   void *priv)
+{
+	const char *signature;
+	__u32 nr_desc;
+	efi_status_t status;
+	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));
+
+	p->efi->efi_systab		= (unsigned long)sys_table_arg;
+	p->efi->efi_memdesc_size	= *map->desc_size;
+	p->efi->efi_memdesc_version	= *map->desc_ver;
+	p->efi->efi_memmap		= (unsigned long)*map->map;
+	p->efi->efi_memmap_size		= *map->map_size;
+
+#ifdef CONFIG_X86_64
+	p->efi->efi_systab_hi		= (unsigned long)sys_table_arg >> 32;
+	p->efi->efi_memmap_hi		= (unsigned long)*map->map >> 32;
+#endif
+
+	return EFI_SUCCESS;
+}
+
+static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
+{
+	unsigned long map_sz, key, desc_size, buff_size;
+	efi_memory_desc_t *mem_map;
+	struct setup_data *e820ext = NULL;
+	__u32 e820ext_size = 0;
+	efi_status_t status;
+	__u32 desc_version;
+	struct efi_boot_memmap map;
+	struct exit_boot_struct priv;
+
+	map.map			= &mem_map;
+	map.map_size		= &map_sz;
+	map.desc_size		= &desc_size;
+	map.desc_ver		= &desc_version;
+	map.key_ptr		= &key;
+	map.buff_size		= &buff_size;
+	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(sys_table, handle, &map, &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 a pointer to a boot_params structure, and NULL
+ * on failure.
+ */
+struct boot_params *
+efi_main(struct efi_config *c, struct boot_params *boot_params)
+{
+	struct desc_ptr *gdt = NULL;
+	efi_loaded_image_t *image;
+	struct setup_header *hdr = &boot_params->hdr;
+	efi_status_t status;
+	struct desc_struct *desc;
+	void *handle;
+	efi_system_table_t *_table;
+	unsigned long cmdline_paddr;
+
+	efi_early = c;
+
+	_table = (efi_system_table_t *)(unsigned long)efi_early->table;
+	handle = (void *)(unsigned long)efi_early->image_handle;
+
+	sys_table = _table;
+
+	/* Check if we were booted by the EFI firmware */
+	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+		goto fail;
+
+	if (efi_is_64bit())
+		setup_boot_services64(efi_early);
+	else
+		setup_boot_services32(efi_early);
+
+	/*
+	 * make_boot_params() may have been called before efi_main(), in which
+	 * case this is the second time we parse the cmdline. This is ok,
+	 * parsing the cmdline multiple times does not have side-effects.
+	 */
+	cmdline_paddr = ((u64)hdr->cmd_line_ptr |
+			 ((u64)boot_params->ext_cmd_line_ptr << 32));
+	efi_parse_options((char *)cmdline_paddr);
+
+	/*
+	 * 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(sys_table);
+
+	/* Ask the firmware to clear memory on unclean shutdown */
+	efi_enable_reset_attack_mitigation(sys_table);
+	efi_retrieve_tpm2_eventlog(sys_table);
+
+	setup_graphics(boot_params);
+
+	setup_efi_pci(boot_params);
+
+	setup_quirks(boot_params);
+
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+				sizeof(*gdt), (void **)&gdt);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to allocate memory for 'gdt' structure\n");
+		goto fail;
+	}
+
+	gdt->size = 0x800;
+	status = efi_low_alloc(sys_table, gdt->size, 8,
+			   (unsigned long *)&gdt->address);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "Failed to allocate memory for 'gdt'\n");
+		goto fail;
+	}
+
+	/*
+	 * If the kernel isn't already loaded at the preferred load
+	 * address, relocate it.
+	 */
+	if (hdr->pref_address != hdr->code32_start) {
+		unsigned long bzimage_addr = hdr->code32_start;
+		status = efi_relocate_kernel(sys_table, &bzimage_addr,
+					     hdr->init_size, hdr->init_size,
+					     hdr->pref_address,
+					     hdr->kernel_alignment);
+		if (status != EFI_SUCCESS) {
+			efi_printk(sys_table, "efi_relocate_kernel() failed!\n");
+			goto fail;
+		}
+
+		hdr->pref_address = hdr->code32_start;
+		hdr->code32_start = bzimage_addr;
+	}
+
+	status = exit_boot(boot_params, handle);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table, "exit_boot() failed!\n");
+		goto fail;
+	}
+
+	memset((char *)gdt->address, 0x0, gdt->size);
+	desc = (struct desc_struct *)gdt->address;
+
+	/* The first GDT is a dummy. */
+	desc++;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		/* __KERNEL32_CS */
+		desc->limit0	= 0xffff;
+		desc->base0	= 0x0000;
+		desc->base1	= 0x0000;
+		desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
+		desc->s		= DESC_TYPE_CODE_DATA;
+		desc->dpl	= 0;
+		desc->p		= 1;
+		desc->limit1	= 0xf;
+		desc->avl	= 0;
+		desc->l		= 0;
+		desc->d		= SEG_OP_SIZE_32BIT;
+		desc->g		= SEG_GRANULARITY_4KB;
+		desc->base2	= 0x00;
+
+		desc++;
+	} else {
+		/* Second entry is unused on 32-bit */
+		desc++;
+	}
+
+	/* __KERNEL_CS */
+	desc->limit0	= 0xffff;
+	desc->base0	= 0x0000;
+	desc->base1	= 0x0000;
+	desc->type	= SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
+	desc->s		= DESC_TYPE_CODE_DATA;
+	desc->dpl	= 0;
+	desc->p		= 1;
+	desc->limit1	= 0xf;
+	desc->avl	= 0;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		desc->l = 1;
+		desc->d = 0;
+	} else {
+		desc->l = 0;
+		desc->d = SEG_OP_SIZE_32BIT;
+	}
+	desc->g		= SEG_GRANULARITY_4KB;
+	desc->base2	= 0x00;
+	desc++;
+
+	/* __KERNEL_DS */
+	desc->limit0	= 0xffff;
+	desc->base0	= 0x0000;
+	desc->base1	= 0x0000;
+	desc->type	= SEG_TYPE_DATA | SEG_TYPE_READ_WRITE;
+	desc->s		= DESC_TYPE_CODE_DATA;
+	desc->dpl	= 0;
+	desc->p		= 1;
+	desc->limit1	= 0xf;
+	desc->avl	= 0;
+	desc->l		= 0;
+	desc->d		= SEG_OP_SIZE_32BIT;
+	desc->g		= SEG_GRANULARITY_4KB;
+	desc->base2	= 0x00;
+	desc++;
+
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		/* Task segment value */
+		desc->limit0	= 0x0000;
+		desc->base0	= 0x0000;
+		desc->base1	= 0x0000;
+		desc->type	= SEG_TYPE_TSS;
+		desc->s		= 0;
+		desc->dpl	= 0;
+		desc->p		= 1;
+		desc->limit1	= 0x0;
+		desc->avl	= 0;
+		desc->l		= 0;
+		desc->d		= 0;
+		desc->g		= SEG_GRANULARITY_4KB;
+		desc->base2	= 0x00;
+		desc++;
+	}
+
+	asm volatile("cli");
+	asm volatile ("lgdt %0" : : "m" (*gdt));
+
+	return boot_params;
+fail:
+	efi_printk(sys_table, "efi_main() failed!\n");
+
+	return NULL;
+}