drivers/firmware/efi/libstub/efi-stub-entry.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/efi.h>
   4 #include <asm/efi.h>
   5
   6 #include "efistub.h"
   7
   8 /*
   9  * EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and
  10  * LoongArch. This is the entrypoint that is described in the PE/COFF header
  11  * of the core kernel.
  12  */
  13 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
  14                                    efi_system_table_t *systab)
  15 {
  16         efi_loaded_image_t *image;
  17         efi_status_t status;
  18         unsigned long image_addr;
  19         unsigned long image_size = 0;
  20         /* addr/point and size pairs for memory management*/
  21         char *cmdline_ptr = NULL;
  22         efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
  23         unsigned long reserve_addr = 0;
  24         unsigned long reserve_size = 0;
  25
  26         WRITE_ONCE(efi_system_table, systab);
  27
  28         /* Check if we were booted by the EFI firmware */
  29         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
  30                 return EFI_INVALID_PARAMETER;
  31
  32         /*
  33          * Get a handle to the loaded image protocol.  This is used to get
  34          * information about the running image, such as size and the command
  35          * line.
  36          */
  37         status = efi_bs_call(handle_protocol, handle, &loaded_image_proto,
  38                              (void *)&image);
  39         if (status != EFI_SUCCESS) {
  40                 efi_err("Failed to get loaded image protocol\n");
  41                 return status;
  42         }
  43
  44         status = efi_handle_cmdline(image, &cmdline_ptr);
  45         if (status != EFI_SUCCESS)
  46                 return status;
  47
  48         efi_info("Booting Linux Kernel...\n");
  49
  50         status = handle_kernel_image(&image_addr, &image_size,
  51                                      &reserve_addr,
  52                                      &reserve_size,
  53                                      image, handle);
  54         if (status != EFI_SUCCESS) {
  55                 efi_err("Failed to relocate kernel\n");
  56                 return status;
  57         }
  58
  59         status = efi_stub_common(handle, image, image_addr, cmdline_ptr);
  60
  61         efi_free(image_size, image_addr);
  62         efi_free(reserve_size, reserve_addr);
  63
  64         return status;
  65 }