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 static unsigned long screen_info_offset;
   9
  10 struct screen_info *alloc_screen_info(void)
  11 {
  12         if (IS_ENABLED(CONFIG_ARM))
  13                 return __alloc_screen_info();
  14         return (void *)&screen_info + screen_info_offset;
  15 }
  16
  17 /*
  18  * EFI entry point for the generic EFI stub used by ARM, arm64, RISC-V and
  19  * LoongArch. This is the entrypoint that is described in the PE/COFF header
  20  * of the core kernel.
  21  */
  22 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
  23                                    efi_system_table_t *systab)
  24 {
  25         efi_loaded_image_t *image;
  26         efi_status_t status;
  27         unsigned long image_addr;
  28         unsigned long image_size = 0;
  29         /* addr/point and size pairs for memory management*/
  30         char *cmdline_ptr = NULL;
  31         efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
  32         unsigned long reserve_addr = 0;
  33         unsigned long reserve_size = 0;
  34
  35         WRITE_ONCE(efi_system_table, systab);
  36
  37         /* Check if we were booted by the EFI firmware */
  38         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
  39                 return EFI_INVALID_PARAMETER;
  40
  41         /*
  42          * Get a handle to the loaded image protocol.  This is used to get
  43          * information about the running image, such as size and the command
  44          * line.
  45          */
  46         status = efi_bs_call(handle_protocol, handle, &loaded_image_proto,
  47                              (void *)&image);
  48         if (status != EFI_SUCCESS) {
  49                 efi_err("Failed to get loaded image protocol\n");
  50                 return status;
  51         }
  52
  53         status = efi_handle_cmdline(image, &cmdline_ptr);
  54         if (status != EFI_SUCCESS)
  55                 return status;
  56
  57         efi_info("Booting Linux Kernel...\n");
  58
  59         status = handle_kernel_image(&image_addr, &image_size,
  60                                      &reserve_addr,
  61                                      &reserve_size,
  62                                      image, handle);
  63         if (status != EFI_SUCCESS) {
  64                 efi_err("Failed to relocate kernel\n");
  65                 return status;
  66         }
  67
  68         screen_info_offset = image_addr - (unsigned long)image->image_base;
  69
  70         status = efi_stub_common(handle, image, image_addr, cmdline_ptr);
  71
  72         efi_free(image_size, image_addr);
  73         efi_free(reserve_size, reserve_addr);
  74
  75         return status;
  76 }