/*
   *  EFI application loader
   *
   *  Copyright (c) 2016 Alexander Graf
   *
   *  SPDX-License-Identifier:     GPL-2.0+
   */
  
  #include <charset.h>
  #include <common.h>
  #include <command.h>
  #include <dm.h>
  #include <efi_loader.h>
  #include <efi_selftest.h>
  #include <errno.h>
  #include <linux/libfdt.h>
  #include <linux/libfdt_env.h>
  #include <memalign.h>
  #include <asm/global_data.h>
  #include <asm-generic/sections.h>
  #include <linux/linkage.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  static uint8_t efi_obj_list_initalized;
  
  static struct efi_device_path *bootefi_image_path;
  static struct efi_device_path *bootefi_device_path;
  
  /* Initialize and populate EFI object list */
  static void efi_init_obj_list(void)
  {
  	efi_obj_list_initalized = 1;
  
  	/* Initialize EFI driver uclass */
  	efi_driver_init();
  
  	efi_console_register();
  #ifdef CONFIG_PARTITIONS
  	efi_disk_register();
  #endif
  #if defined(CONFIG_LCD) || defined(CONFIG_DM_VIDEO)
  	efi_gop_register();
  #endif
  #ifdef CONFIG_CMD_NET
  	efi_net_register();
  #endif
  #ifdef CONFIG_GENERATE_SMBIOS_TABLE
  	efi_smbios_register();
  #endif
  	efi_watchdog_register();
  
  	/* Initialize EFI runtime services */
  	efi_reset_system_init();
  	efi_get_time_init();
  }
  
  /*
   * Set the load options of an image from an environment variable.
   *
   * @loaded_image_info:	the image
   * @env_var:		name of the environment variable
   */
  static void set_load_options(struct efi_loaded_image *loaded_image_info,
  			     const char *env_var)
  {
  	size_t size;
  	const char *env = env_get(env_var);
  
  	loaded_image_info->load_options = NULL;
  	loaded_image_info->load_options_size = 0;
  	if (!env)
  		return;
  	size = strlen(env) + 1;
  	loaded_image_info->load_options = calloc(size, sizeof(u16));
  	if (!loaded_image_info->load_options) {
  		printf("ERROR: Out of memory
  ");
  		return;
  	}
  	utf8_to_utf16(loaded_image_info->load_options, (u8 *)env, size);
  	loaded_image_info->load_options_size = size * 2;
  }
  
  static void *copy_fdt(void *fdt)
  {
  	u64 fdt_size = fdt_totalsize(fdt);
  	unsigned long fdt_ram_start = -1L, fdt_pages;
  	u64 new_fdt_addr;
  	void *new_fdt;
  	int i;
  
          for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
                  u64 ram_start = gd->bd->bi_dram[i].start;
                  u64 ram_size = gd->bd->bi_dram[i].size;
  
  		if (!ram_size)
  			continue;
  
  		if (ram_start < fdt_ram_start)
  			fdt_ram_start = ram_start;
  	}
  
  	/* Give us at least 4kb breathing room */
  	fdt_size = ALIGN(fdt_size + 4096, EFI_PAGE_SIZE);
  	fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
  
  	/* Safe fdt location is at 128MB */
  	new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
  	if (efi_allocate_pages(1, EFI_RUNTIME_SERVICES_DATA, fdt_pages,
  			       &new_fdt_addr) != EFI_SUCCESS) {
  		/* If we can't put it there, put it somewhere */
  		new_fdt_addr = (ulong)memalign(EFI_PAGE_SIZE, fdt_size);
  		if (efi_allocate_pages(1, EFI_RUNTIME_SERVICES_DATA, fdt_pages,
  				       &new_fdt_addr) != EFI_SUCCESS) {
  			printf("ERROR: Failed to reserve space for FDT
  ");
  			return NULL;
  		}
  	}
  
  	new_fdt = (void*)(ulong)new_fdt_addr;
  	memcpy(new_fdt, fdt, fdt_totalsize(fdt));
  	fdt_set_totalsize(new_fdt, fdt_size);
  
  	return new_fdt;
  }
  
  static efi_status_t efi_do_enter(
  			efi_handle_t image_handle, struct efi_system_table *st,
  			EFIAPI efi_status_t (*entry)(
  				efi_handle_t image_handle,
  				struct efi_system_table *st))
  {
  	efi_status_t ret = EFI_LOAD_ERROR;
  
  	if (entry)
  		ret = entry(image_handle, st);
  	st->boottime->exit(image_handle, ret, 0, NULL);
  	return ret;
  }
  
  #ifdef CONFIG_ARM64
  static efi_status_t efi_run_in_el2(EFIAPI efi_status_t (*entry)(
  			efi_handle_t image_handle, struct efi_system_table *st),
  			efi_handle_t image_handle, struct efi_system_table *st)
  {
  	/* Enable caches again */
  	dcache_enable();
  
  	return efi_do_enter(image_handle, st, entry);
  }
  #endif
  
  /*
   * Load an EFI payload into a newly allocated piece of memory, register all
   * EFI objects it would want to access and jump to it.
   */
  static efi_status_t do_bootefi_exec(void *efi, void *fdt,
  				    struct efi_device_path *device_path,
  				    struct efi_device_path *image_path)
  {
  	struct efi_loaded_image loaded_image_info = {};
  	struct efi_object loaded_image_info_obj = {};
  	struct efi_device_path *memdp = NULL;
  	ulong ret;
  
  	EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
  				     struct efi_system_table *st);
  	ulong fdt_pages, fdt_size, fdt_start, fdt_end;
  	const efi_guid_t fdt_guid = EFI_FDT_GUID;
  	bootm_headers_t img = { 0 };
  
  	/*
  	 * Special case for efi payload not loaded from disk, such as
  	 * 'bootefi hello' or for example payload loaded directly into
  	 * memory via jtag/etc:
  	 */
  	if (!device_path && !image_path) {
  		printf("WARNING: using memory device/image path, this may confuse some payloads!
  ");
  		/* actual addresses filled in after efi_load_pe() */
  		memdp = efi_dp_from_mem(0, 0, 0);
  		device_path = image_path = memdp;
  	} else {
  		assert(device_path && image_path);
  	}
  
  	/* Initialize and populate EFI object list */
  	if (!efi_obj_list_initalized)
  		efi_init_obj_list();
  
  	efi_setup_loaded_image(&loaded_image_info, &loaded_image_info_obj,
  			       device_path, image_path);
  
  	/*
  	 * gd lives in a fixed register which may get clobbered while we execute
  	 * the payload. So save it here and restore it on every callback entry
  	 */
  	efi_save_gd();
  
  	if (fdt && !fdt_check_header(fdt)) {
  		/* Prepare fdt for payload */
  		fdt = copy_fdt(fdt);
  
  		if (image_setup_libfdt(&img, fdt, 0, NULL)) {
  			printf("ERROR: Failed to process device tree
  ");
  			return -EINVAL;
  		}
  
  		/* Link to it in the efi tables */
  		efi_install_configuration_table(&fdt_guid, fdt);
  
  		/* And reserve the space in the memory map */
  		fdt_start = ((ulong)fdt) & ~EFI_PAGE_MASK;
  		fdt_end = ((ulong)fdt) + fdt_totalsize(fdt);
  		fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
  		fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
  		/* Give a bootloader the chance to modify the device tree */
  		fdt_pages += 2;
  		efi_add_memory_map(fdt_start, fdt_pages,
  				   EFI_BOOT_SERVICES_DATA, true);
  	} else {
  		printf("WARNING: Invalid device tree, expect boot to fail
  ");
  		efi_install_configuration_table(&fdt_guid, NULL);
  	}
  
  	/* Transfer environment variable bootargs as load options */
  	set_load_options(&loaded_image_info, "bootargs");
  	/* Load the EFI payload */
  	entry = efi_load_pe(efi, &loaded_image_info);
  	if (!entry) {
  		ret = -ENOENT;
  		goto exit;
  	}
  
  	if (memdp) {
  		struct efi_device_path_memory *mdp = (void *)memdp;
  		mdp->memory_type = loaded_image_info.image_code_type;
  		mdp->start_address = (uintptr_t)loaded_image_info.image_base;
  		mdp->end_address = mdp->start_address +
  				loaded_image_info.image_size;
  	}
  
  	/* we don't support much: */
  	env_set("efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported",
  		"{ro,boot}(blob)0000000000000000");
  
  	/* Call our payload! */
  	debug("%s:%d Jumping to 0x%lx
  ", __func__, __LINE__, (long)entry);
  
  	if (setjmp(&loaded_image_info.exit_jmp)) {
  		ret = loaded_image_info.exit_status;
  		goto exit;
  	}
  
  #ifdef CONFIG_ARM64
  	/* On AArch64 we need to make sure we call our payload in < EL3 */
  	if (current_el() == 3) {
  		smp_kick_all_cpus();
  		dcache_disable();	/* flush cache before switch to EL2 */
  
  		/* Move into EL2 and keep running there */
  		armv8_switch_to_el2((ulong)entry,
  				    (ulong)&loaded_image_info_obj.handle,
  				    (ulong)&systab, 0, (ulong)efi_run_in_el2,
  				    ES_TO_AARCH64);
  
  		/* Should never reach here, efi exits with longjmp */
  		while (1) { }
  	}
  #endif
  
  	ret = efi_do_enter(loaded_image_info_obj.handle, &systab, entry);
  
  exit:
  	/* image has returned, loaded-image obj goes *poof*: */
  	list_del(&loaded_image_info_obj.link);
  
  	return ret;
  }
  
  static int do_bootefi_bootmgr_exec(unsigned long fdt_addr)
  {
  	struct efi_device_path *device_path, *file_path;
  	void *addr;
  	efi_status_t r;
  
  	/* Initialize and populate EFI object list */
  	if (!efi_obj_list_initalized)
  		efi_init_obj_list();
  
  	/*
  	 * gd lives in a fixed register which may get clobbered while we execute
  	 * the payload. So save it here and restore it on every callback entry
  	 */
  	efi_save_gd();
  
  	addr = efi_bootmgr_load(&device_path, &file_path);
  	if (!addr)
  		return 1;
  
  	printf("## Starting EFI application at %p ...
  ", addr);
  	r = do_bootefi_exec(addr, (void *)fdt_addr, device_path, file_path);
  	printf("## Application terminated, r = %lu
  ",
  	       r & ~EFI_ERROR_MASK);
  
  	if (r != EFI_SUCCESS)
  		return 1;
  
  	return 0;
  }
  
  /* Interpreter command to boot an arbitrary EFI image from memory */
  static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	char *saddr, *sfdt;
  	unsigned long addr, fdt_addr = 0;
  	efi_status_t r;
  
  	if (argc < 2)
  		return CMD_RET_USAGE;
  #ifdef CONFIG_CMD_BOOTEFI_HELLO
  	if (!strcmp(argv[1], "hello")) {
  		ulong size = __efi_helloworld_end - __efi_helloworld_begin;
  
  		saddr = env_get("loadaddr");
  		if (saddr)
  			addr = simple_strtoul(saddr, NULL, 16);
  		else
  			addr = CONFIG_SYS_LOAD_ADDR;
  		memcpy((char *)addr, __efi_helloworld_begin, size);
  	} else
  #endif
  #ifdef CONFIG_CMD_BOOTEFI_SELFTEST
  	if (!strcmp(argv[1], "selftest")) {
  		struct efi_loaded_image loaded_image_info = {};
  		struct efi_object loaded_image_info_obj = {};
  
  		/* Construct a dummy device path. */
  		bootefi_device_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
  						      (uintptr_t)&efi_selftest,
  						      (uintptr_t)&efi_selftest);
  		bootefi_image_path = efi_dp_from_file(NULL, 0, "\\selftest");
  
  		efi_setup_loaded_image(&loaded_image_info,
  				       &loaded_image_info_obj,
  				       bootefi_device_path, bootefi_image_path);
  		/*
  		 * gd lives in a fixed register which may get clobbered while we
  		 * execute the payload. So save it here and restore it on every
  		 * callback entry
  		 */
  		efi_save_gd();
  		/* Initialize and populate EFI object list */
  		if (!efi_obj_list_initalized)
  			efi_init_obj_list();
  		/* Transfer environment variable efi_selftest as load options */
  		set_load_options(&loaded_image_info, "efi_selftest");
  		/* Execute the test */
  		r = efi_selftest(loaded_image_info_obj.handle, &systab);
  		efi_restore_gd();
  		free(loaded_image_info.load_options);
  		list_del(&loaded_image_info_obj.link);
  		return r != EFI_SUCCESS;
  	} else
  #endif
  	if (!strcmp(argv[1], "bootmgr")) {
  		unsigned long fdt_addr = 0;
  
  		if (argc > 2)
  			fdt_addr = simple_strtoul(argv[2], NULL, 16);
  
  		return do_bootefi_bootmgr_exec(fdt_addr);
  	} else {
  		saddr = argv[1];
  
  		addr = simple_strtoul(saddr, NULL, 16);
  		/* Check that a numeric value was passed */
  		if (!addr && *saddr != '0')
  			return CMD_RET_USAGE;
  
  		if (argc > 2) {
  			sfdt = argv[2];
  			fdt_addr = simple_strtoul(sfdt, NULL, 16);
  		}
  	}
  
  	printf("## Starting EFI application at %08lx ...
  ", addr);
  	r = do_bootefi_exec((void *)addr, (void *)fdt_addr,
  			    bootefi_device_path, bootefi_image_path);
  	printf("## Application terminated, r = %lu
  ",
  	       r & ~EFI_ERROR_MASK);
  
  	if (r != EFI_SUCCESS)
  		return 1;
  	else
  		return 0;
  }
  
  #ifdef CONFIG_SYS_LONGHELP
  static char bootefi_help_text[] =
  	"<image address> [fdt address]
  "
  	"  - boot EFI payload stored at address <image address>.
  "
  	"    If specified, the device tree located at <fdt address> gets
  "
  	"    exposed as EFI configuration table.
  "
  #ifdef CONFIG_CMD_BOOTEFI_HELLO
  	"bootefi hello
  "
  	"  - boot a sample Hello World application stored within U-Boot
  "
  #endif
  #ifdef CONFIG_CMD_BOOTEFI_SELFTEST
  	"bootefi selftest
  "
  	"  - boot an EFI selftest application stored within U-Boot
  "
  	"    Use environment variable efi_selftest to select a single test.
  "
  	"    Use 'setenv efi_selftest list' to enumerate all tests.
  "
  #endif
  	"bootefi bootmgr [fdt addr]
  "
  	"  - load and boot EFI payload based on BootOrder/BootXXXX variables.
  "
  	"
  "
  	"    If specified, the device tree located at <fdt address> gets
  "
  	"    exposed as EFI configuration table.
  ";
  #endif
  
  U_BOOT_CMD(
  	bootefi, 3, 0, do_bootefi,
  	"Boots an EFI payload from memory",
  	bootefi_help_text
  );
  
  static int parse_partnum(const char *devnr)
  {
  	const char *str = strchr(devnr, ':');
  	if (str) {
  		str++;
  		return simple_strtoul(str, NULL, 16);
  	}
  	return 0;
  }
  
  void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
  {
  	char filename[32] = { 0 }; /* dp->str is u16[32] long */
  	char *s;
  
  	if (strcmp(dev, "Net")) {
  		struct blk_desc *desc;
  		int part;
  
  		desc = blk_get_dev(dev, simple_strtol(devnr, NULL, 10));
  		if (!desc)
  			return;
  		part = parse_partnum(devnr);
  
  		bootefi_device_path = efi_dp_from_part(desc, part);
  	} else {
  #ifdef CONFIG_CMD_NET
  		bootefi_device_path = efi_dp_from_eth();
  #endif
  	}
  
  	if (!path)
  		return;
  
  	if (strcmp(dev, "Net")) {
  		/* Add leading / to fs paths, because they're absolute */
  		snprintf(filename, sizeof(filename), "/%s", path);
  	} else {
  		snprintf(filename, sizeof(filename), "%s", path);
  	}
  	/* DOS style file path: */
  	s = filename;
  	while ((s = strchr(s, '/')))
  		*s++ = '\\';
  	bootefi_image_path = efi_dp_from_file(NULL, 0, filename);
  }