Extends the installer to write a GRUB chainload ESP layout when
bootloader = "grub" is set in config. Changes GeneralConfig, DiskOption,
fetch_bootloaders, with_whole_disk, with_whole_disk_ext4, and both CLI
binaries. When GRUB mode is active, the ESP contains GRUB as primary
(BOOTX64.EFI), grub.cfg, and the Redox bootloader as chainload target
(EFI/REDBEAR/redbear.efi).
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
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