Commit Graph

52 Commits

Author SHA1 Message Date
Pierre Gondois
98f2808115 DynamicTablesPkg: AML grammar definition
ASL is a source language for defining ACPI objects including
writing ACPI control methods. An ASL file is compiled using
an ASL compiler tool to generate ACPI Machine Language (AML).
This AML bytecode is processed by the ACPI AML interpreter
that runs as part of an Operating System (OS).

Both ASL and AML are declarative languages. Although they
are closely related they are different languages.

ASL statements declare objects. Each object has three parts,
two of which can be NULL:
  Object := ObjectType FixedList VariableList

The AML grammar defines corresponding encodings that makes
up the AML byte stream.

This patch introduces the AML grammar definitions used by
AmlLib for encoding/decoding AML byte streams.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois
292e540854 DynamicTablesPkg: AmlLib definitions
Dynamic AML is a solution to generate Definition Block tables
at runtime. Dynamic AML provides the following techniques for
generating AML tables.
  - AML Fixup
  - AML Codegen
  - AML Fixup + Codegen

AML fixup involves patching small sections of a template AML
code at runtime, while AML Codegen provides APIs to generate
small sections of AML code at runtime. A combination of
Fixup and Codegen can also be used.

AML has a complex grammar. To simplify the generation of
AML tables, Dynamic AML introduces AmlLib that provides a
rich set of APIs for parsing, traversing, fixup, codegen
and serialisation of AML byte code.

This patch introduces the definitions used by AmlLib.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00