armandomontanez abce1d427c
Introduce initial Bazel build (#1705)
* Build boot_stage2 with Bazel

Introduces the initial foundations of a Bazel build, including a
toolchain, critical generated headers, platform patterns, and enough
BUILD files to build boot_stage2.

* Bazel libraries to support picotool

* Move SDK defines to toolchain

* Switch to `archive_override` in MODULE.bazel

Uses archive_override where applicable to allow transitive bzlmod deps
to propagate.

* Multiplatform objcopy selection in Bazel build

Makes an objcopy alias that redirects to the objcopy tool for the
current exec platform, which allows boot_stage2 to build on Linux,
macOS, and Windows.

* Generate Bazel build files

Adds initial set of generated Bazel build files. Note that these do not
yet build, as dependency cycles are present.

* Fix dependency cycles in Bazel build

Fixes many dependency cycles, some were unintentionally created by the
build file generator, others are true dependency cycles that require
manual workarounds.

* Silence warning in pico_stdio Bazel build

Silences a stray warning in the Bazel build.

* Fix wildcard Bazel build

This makes `bazel build //...` succeed, and also prevents the fetching
of toolchains that aren't compatible with the current execution
environment (i.e. Windows computers will no longer try to download macOS
toolchains).

* Get the SDK working

Finishes out the remainder of the work required to successfully compile
a working blinky example.

* Fix UART stdio dependencies in Bazel build

Fixes some dependencies around pico_stdlib so that pico_stdlib links
properly and UART stdio works.

* Add linux support to Bazel build

* Get Bazel deps from registry

Adds external an external registry for resolving Bazel module
dependencies.

* Fix host configuration for picotool

Provides the appropriate defines for host builds to support the picotool
build.

* Remove -ffreestanding from Bazel toolchain

The -ffreestanding toolchain flag is quite strict, so remove it from the
Bazel toolchain.

* Remove unused .bzl file

* Reduce Bazel compiler flags

Cuts out most of the Bazel toolchain flags and only specifies the
bare-minimum set of flags. Also, adds wrapper linker flags for functions
the SDK wraps.

* Get USB serial working

Adds initial TinyUSB support and enough integration to get USB serial
working.

* Remove "Generated build file"

Removes comments that indicates BUILD.bazel files are generated. This
was used during initial bringup to indicate hand-crafted vs
automatically generated BUILD.bazel files.

* Do not build USB libraries unless configured

Prevents USB libraries from being built unless the build is properly
configured to use them.

* Switch to rules_cc toolchains

Moves toolchain configuration to use the new rules in rules_cc.

* Minor cleanup in parse_version.py

Cleans up trailing whitespace and runs the black formatter on
parse_version.py.

* Simplify constraint dimensions in Bazel build

Consolidates the class/chip constraint settings to be a single
constraint_setting with a config_setting that represents the rp2 class.

* Update pin of rules_cc in Bazel build

Includes a necessary fix for the target_compatible_with expression in
the cc_toolchain to work as intended.

* Move toolchains from pico.bzl to BUILD.bazel

Moves toolchain definitions from pico.bzl to BUILD.bazel to make them
easier to find and read.

* Run buildifier on Bazel build files

Fix trivial formatting issues by running buildifier on all BUILD.bazel
files.

* Make objcopy rule

Makes a simple objcopy rule to remove direct references to the ARM
toolchains.

* Fix link flags in Bazel build

Critical flags were not being applied to link steps. This applies -mcpu
and -mthumb to the link steps to make the produced binaries work again.

* Mention missing host build support

* Fix various Bazel library rules

* pico_bit_ops was incomplete.
* pico_double and pico_float were trying to link in the "none"
  implementation.

* Extend Bazel build documentation

Improves documentation and comments across the Bazel build.

* Clean up auxilary tools in Bazel build

Switches genrules to use skylib rules to simplify things. Reworks
version header generation to use the Bazel module version rather than
parsing CMake.

* Update boot_stage2 Bazel build file

Moves `includes` to be enumerated on the correct library.

* Add WORKSPACE version fallback

WORKSPACE Bazel projects don't support querying module version, so add a
fallback of '0.0.1-WORKSPACE' so the build can succeed.

* Fix malloc handling in Bazel build

* Fix Bazel dependency cycle in pico_malloc

* Prevent malloc from being linked into boot_stage2

Prevents Bazel from ever trying to link malloc into the boot_stage2
binary.

* Remove custom bootloader platform

A dedicated boot_stage2 platform introduces a lot of complexity that
needs to be more thought-through.
2024-06-04 18:50:32 -05:00
..
2021-03-04 21:22:48 -06:00
2021-01-20 10:44:27 -06:00

This is a basic set of replacement library implementations sufficient to get simple applications running on your computer (Raspberry Pi OS, Linux, macOS or Windows using Cygwin or Windows Subsystem for Linux). It is selected by PICO_PLATFORM=host in your CMake build

This can be extremely useful for testing and debugging higher level application code, or porting code which is not yet small enough to run on the RP2040 device itself.

This base level host library provides a minimal environment to compile programs, but is likely sufficient for programs that don't access hardware directly.

It is possible however to inject additional SDK library implementations/simulations to provide more complete functionality. For an example of this see the pico-host-sdl which uses the SDL2 library to add additional library support for pico_multicore, timers/alarms in pico-time and pico-audio/pico-scanvideo from pico-extras