Red Bear OS — microkernel OS in Rust, based on Redox

Derivative of Redox OS (https://www.redox-os.org) adding:
- AMD GPU driver (amdgpu) via LinuxKPI compat layer
- ext4 filesystem support (ext4d scheme daemon)
- ACPI fixes for AMD bare metal (x2APIC, DMAR, IVRS, MCFG)
- Custom branding (hostname, os-release, boot identity)

Build system is full upstream Redox with RBOS overlay in local/.
Patches for kernel, base, and relibc are symlinked from local/patches/
and protected from make clean/distclean. Custom recipes live in
local/recipes/ with symlinks into the recipes/ search path.

Build:  make all CONFIG_NAME=redbear-full
Sync:   ./local/scripts/sync-upstream.sh

mk/depends.mk

@@ -0,0 +1,29 @@
+# Configuration file for the build system dependencies
+
+# Don't check for dependencies if you will be using Podman
+ifneq ($(PODMAN_BUILD),1)
+# Don't check for dependencies if you will be using Hosted Red Bear OS
+ifneq ($(HOSTED_REDOX),1)
+
+# don't check for Rust and Cargo if building on a Nix system
+ifneq ($(NIX_SHELL_BUILD),1)
+ifeq ($(shell which rustup),)
+$(error rustup not found, install from "https://rustup.rs/")
+endif
+endif
+
+# don't check for compile tools, used internally when installing fstools on host
+ifneq ($(SKIP_CHECK_TOOLS),1)
+ifeq ($(shell which cbindgen),)
+$(error cbindgen not found, install from crates.io or from your package manager)
+endif
+ifeq ($(shell which nasm),)
+$(error nasm not found, install from your package manager)
+endif
+ifeq ($(shell which just),)
+$(error 'just' not found, install from crates.io or from your package manager)
+endif
+endif
+
+endif
+endif