Shell Execution Requirements - lersek/edk2 GitHub Wiki

Table of Contents

Shell Requirements

The shell is explicitly defined as a UEFI 2.1+ Application. That means that is has a requirement on a completed system table and many protocols. The shell will use features only found in UEFI 2.3+ (such as SimpleTextInputEx), but will function with a reduced feature set without these features. Note that these reductions in functionality may make the the shell non-spec compliant.

Table Requirements

The shell uses many functions found on the System Table or sub-tables.

System Table

  • EFI Table Header
  • ConsoleInHandle
  • ConIn
  • ConsoleOutHandle
  • ConOut
  • StandardErrorHandle
  • StdErr

Boot Services

All major sections of this table are used.

  • Event, Timer, and Task Priority Services
  • Memory Allocation Services
  • Protocol Handler Services
  • Image Services
  • Miscelaneous Boot Services

Runtime Services

Many sections of this table are used.

  • Variable Services
  • Time Services
  • Miscelaneous Runtime Services

Protocol Dependancy

The shell uses many UEFI standard protocols to perform.

Required

  • gEfiSimpleTextInProtocolGuid
  • gEfiSimpleTextOutProtocolGuid
  • gEfiSimpleFileSystemProtocolGuid
  • gEfiLoadedImageProtocolGuid
  • gEfiComponentName2ProtocolGuid
  • gEfiUnicodeCollation2ProtocolGuid
  • gEfiDevicePathProtocolGuid
  • gEfiDevicePathToTextProtocolGuid
  • gEfiPciRootBridgeIoProtocolGuid
  • gEfiBlockIoProtocolGuid

Optional

These are used for shell nesting operations, but are not required by the first shell instance.

  • gEfiShellProtocolGuid
  • gEfiShellParametersProtocolGuid

Reduced Feature Optional

Lacking these protocols will reduce the feature set.

  • gEfiSimpleTextInputExProtocolGuid

Command Dependant

The main shell and some commands will function without these. Some commands may not function.

  • gEfiSimplePointerProtocolGuid
  • gEfiDriverHealthProtocolGuid
  • gEfiDriverFamilyOverrideProtocolGuid
  • gEfiHiiConfigAccessProtocolGuid
  • gEfiHiiDatabaseProtocolGuid
  • gEfiCpuArchProtocolGuid
  • gEfiIp6ProtocolGuid
  • gEfiIp6ServiceBindingProtocolGuid
  • gEfiIp6ConfigProtocolGuid
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