uefi.rst 1.8 KB

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  1. .. SPDX-License-Identifier: GPL-2.0
  2. =====================================
  3. General note on [U]EFI x86_64 support
  4. =====================================
  5. The nomenclature EFI and UEFI are used interchangeably in this document.
  6. Although the tools below are _not_ needed for building the kernel,
  7. the needed bootloader support and associated tools for x86_64 platforms
  8. with EFI firmware and specifications are listed below.
  9. 1. UEFI specification: http://www.uefi.org
  10. 2. Booting Linux kernel on UEFI x86_64 platform requires bootloader
  11. support. Elilo with x86_64 support can be used.
  12. 3. x86_64 platform with EFI/UEFI firmware.
  13. Mechanics
  14. ---------
  15. - Build the kernel with the following configuration::
  16. CONFIG_FB_EFI=y
  17. CONFIG_FRAMEBUFFER_CONSOLE=y
  18. If EFI runtime services are expected, the following configuration should
  19. be selected::
  20. CONFIG_EFI=y
  21. CONFIG_EFI_VARS=y or m # optional
  22. - Create a VFAT partition on the disk
  23. - Copy the following to the VFAT partition:
  24. elilo bootloader with x86_64 support, elilo configuration file,
  25. kernel image built in first step and corresponding
  26. initrd. Instructions on building elilo and its dependencies
  27. can be found in the elilo sourceforge project.
  28. - Boot to EFI shell and invoke elilo choosing the kernel image built
  29. in first step.
  30. - If some or all EFI runtime services don't work, you can try following
  31. kernel command line parameters to turn off some or all EFI runtime
  32. services.
  33. noefi
  34. turn off all EFI runtime services
  35. reboot_type=k
  36. turn off EFI reboot runtime service
  37. - If the EFI memory map has additional entries not in the E820 map,
  38. you can include those entries in the kernels memory map of available
  39. physical RAM by using the following kernel command line parameter.
  40. add_efi_memmap
  41. include EFI memory map of available physical RAM