dasharo-binaries-paths-convention.md: Add

Signed-off-by: Filip Gołaś <[email protected]>

Author: philipanda

docs/kb/dasharo-binaries-paths-convention.md

@@ -0,0 +1,100 @@
+# Dasharo Binaries Paths Convention
+
+Dasharo firmware binaries are available to download on [dl.3mdeb.com][dl.3mdeb.com]
+and [dlui.dasharo.com][dlui.dasharo.com]. These sources are being managed
+- manually
+- using semi-manual automation
+- fully automated CI
+
+The objective of this document is to describe a standard convention of the
+directory tree and binary names used in Dasharo sources. It will make it easier
+to navigate them and find the releases one is in interested in.
+
+## Directories Convention
+
+The standardised path to a release directory is as follows:
+
+`/<vendor>/<model>/<framework>[_payload]/<version>/`
+
+where:
+- `<vendor>` - hardware vendor, like `novacustom`, `protectli`, `hardkernel`,
+  `pcengines`
+- `<model>` - Precise device model, like `v540tu`, `vp6670`, `odroid-h4`,
+  `apu4`
+- `<framework>` - firmware framework, like `coreboot`, `slimbootloader`, `heads`
+- `[_payload]` - optional, firmware payload, like `_uefi`, `_heads`, `_seabios`
+- `<version>` - Dasharo version, like `v0.9.0`, `v1.7.2-rc1`
+
+Example, path to the v1.0.0 release binaries for Novacustom V540TU laptop:
+- `/novacustom/v540tu/coreboot_uefi/1.0.0/`
+
+### Motivation
+
+#### <framework>[_payload]
+
+Historically, the firmware framework and payload were generally not present in
+the paths, which looked like `/<platform_family>/<version>/`.
+When the support for new frameworks and payloads appeared, new directories
+started to appear, like `/<platform_family>/heads/<version>/` or
+`/<platform_family>/slimbootloader/<version>/` which made the paths
+inconsistent with the older releases.
+
+To fix this inconsistency issue the framework and (optional) payload will
+always be there, even if a platform has only support for a single
+framework/payload combination to reduce the ambiguity.
+
+It's argueable that a firmware framework without a payload makes little sense
+as it won't allow the device to boot. Dasharo Naming Convention allows for
+such cases though, so to reduce the risk of needing to come up with hacks like
+`none` payload and inconsistent lengths of th path to a binary, the `[_payload]`
+field is a part of the same directory name as the `<framework>`.
+
+#### <vendor>/<model>
+
+The idea to separate the `<platform_family>` into the vendor and specific models
+has a couple reasons behind it:
+1. the number of combinations of vendor, microarchitecture and model family
+   resulted in too many directories on a single level
+1. knowing just a model name it could be not that obvious which family
+   it is supposed to belong to
+1. the firmware binaries for all the models from a family could be, or not be
+   compatible with the whole family, it could also change with releases and
+   require changing the directory structure
+1. it was not clear how to release the firmware for just one device from a
+   family
+
+By separating the `vendor` and `model` into independent fields all the issues
+above are solved. An additional bonus is that the user searching for the
+binaries doesn't need to know technical details like the microarchitecture
+of their CPU, just the name of the producer and the model of the device.
+
+[dl.3mdeb.com]: https://dl.3mdeb.com
+[dlui.dasharo.com]: https://dlui.dasharo.com
+
+## Binary Names Convention
+
+To reduce the confusion and risk of mixing up binaries and allow for creating
+multiple variants of a single binary without inconsistencies, the name of the
+binary is also being standardised, and looks like:
+
+`<vendor>_<model>_<framework>[_<payload>]_<version>[_extra].<extension>`
+
+where:
+- `<vendor>` - hardware vendor, like `novacustom`, `protectli`, `hardkernel`,
+  `pcengines`
+- `<model>` - Precise device model, like `v540tu`, `vp6670`, `odroid-h4`,
+  `apu4`
+- `<framework>` - firmware framework, like `coreboot`, `slimbootloader`, `heads`
+- `[_payload]` - optional, firmware payload, like `_uefi`, `_heads`, `_seabios`
+- `<version>` - Dasharo version, like `v0.9.0`, `v1.7.2-rc1`
+- `[_extra]` - optional additional info, like `_dev_signed`, `_btg_provisioned`,
+  `_eom`
+- `<extension>` - `rom` for normal binaries, `cap` for UEFI Capsules, `cab` for
+  FWUPD cabinets etc.
+
+### Motivation
+
+This is especially important for the 3mdeb employees or users which flash their
+devices often. Every binary should contain all the information required to
+distinguish it from any other binary to reduce the risk of bricking the device
+or other mishaps during flashing.