Add some placeholder documentation to explain the basic concept. Once the spec is published, more can be added and this series applied.
Signed-off-by: Simon Glass <[email protected]> --- doc/usage/index.rst | 1 + doc/usage/upl.rst | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) create mode 100644 doc/usage/upl.rst diff --git a/doc/usage/index.rst b/doc/usage/index.rst index ed896dfb3a0..78665fd5759 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -13,6 +13,7 @@ Use U-Boot partitions cmdline semihosting + upl Shell commands -------------- diff --git a/doc/usage/upl.rst b/doc/usage/upl.rst new file mode 100644 index 00000000000..2ae4d4a1178 --- /dev/null +++ b/doc/usage/upl.rst @@ -0,0 +1,27 @@ +Universal Payload +~~~~~~~~~~~~~~~~~ + +Universal Payload (UPL) is an upcoming Industry Standard for firmware +components. UPL is designed to improve interoperability within the firmware +industry, allowing mixing and matching of projects with less friction and fewer +project-specific implementations. UPL is cross-platform, supporting ARM, x86 and +RISC-V initially. + +UPL is defined in termns of two firmware components: + +`Platform Init` + Perhaps initial setup of the hardware and jumps to the payload. + +`Payload` + Selects the OS to boot + +In practice UPL can be used to handle any number of handoffs through the +firmware startup process, with one program acting as platform init and another +acting as the payload. + +UPL provides a standard for three main pieces: + +- file format for the payload, which may comprise multiple images to load +- handoff format for the information the payload needs, such as serial port, + memory layout, etc. +- machine state and register settings at the point of handoff -- 2.42.0.rc2.253.gd59a3bf2b4-goog
