text: // SPDX-License-Identifier: GPL-2.0+
  /*
   *  EFI application tables support
   *
   *  Copyright (c) 2016 Alexander Graf
   */
  
  #include <common.h>
  #include <efi_loader.h>
  #include <mapmem.h>
  #include <smbios.h>
  
  static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
  
  /*
   * Install the SMBIOS table as a configuration table.
   *
   * @return	status code
   */
  efi_status_t efi_smbios_register(void)
  {
  	/* Map within the low 32 bits, to allow for 32bit SMBIOS tables */
  	u64 dmi_addr = U32_MAX;
  	efi_status_t ret;
  	void *dmi;
  
  	/* Reserve 4kiB page for SMBIOS */
  	ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
  				 EFI_RUNTIME_SERVICES_DATA, 1, &dmi_addr);
  
  	if (ret != EFI_SUCCESS) {
  		/* Could not find space in lowmem, use highmem instead */
  		ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
  					 EFI_RUNTIME_SERVICES_DATA, 1,
  					 &dmi_addr);
  
  		if (ret != EFI_SUCCESS)
  			return ret;
  	}
  
  	/*
  	 * Generate SMBIOS tables - we know that efi_allocate_pages() returns
  	 * a 4k-aligned address, so it is safe to assume that
  	 * write_smbios_table() will write the table at that address.
  	 *
  	 * Note that on sandbox, efi_allocate_pages() unfortunately returns a
  	 * pointer even though it uses a uint64_t type. Convert it.
  	 */
  	assert(!(dmi_addr & 0xf));
  	dmi = (void *)(uintptr_t)dmi_addr;
  	write_smbios_table(map_to_sysmem(dmi));
  
  	/* And expose them to our EFI payload */
  	return efi_install_configuration_table(&smbios_guid, dmi);
  }
  