HomeCore is single-threaded C11 bare-metal firmware. It provides a serial shell, a VFS with RAM files and mounted FAT and littlefs volumes, user sessions, a 1 kHz uptime clock, and the G2BASIC interpreter. This reference covers the public headers under include/homecore. The source is on GitHub.

Guides

Guide	Contents
A first session	A guided ten-minute tour in QEMU
BASIC guide	Programming HomeCore in BASIC, with examples
Architecture	Layers, startup, memory, and runtime contracts
Development	Setup, builds, configuration, tests, and debugging
C coding standard	Language, style, memory, and interrupt rules
Drivers	Device descriptions, bindings, initialization, interrupts, and each driver
Device bindings	Generated reference of every compatible, its properties, and the boards using it
Files and storage	The VFS, mounted filesystems (FAT, littlefs), and block devices
Shell and system services	Commands, sessions, files, and uptime
Extending	Adding shell commands and VFS device nodes
Porting	Adding boards, SoCs, and architecture support
Versioning	SemVer rules, the public interface, and the changelog

Boards

Board	Core	Status
LM3S6965EVB	Cortex-M3, 64 KB RAM	QEMU tested in CI
STM32F4DISCOVERY	Cortex-M4F, 128 KB RAM	Builds in CI; hardware validation pending
STM32VLDISCOVERY	Cortex-M3, 8 KB RAM	QEMU tested in CI; hardware validation pending

Supported boards compares features, memory, and build presets.

Layers

The API is grouped by layer. Each header defines one module group.

Layer	Modules	Header location
Hardware abstraction	Architecture, SoC, Board support	`homecore/arch`, `homecore/soc`, `homecore/board`
Drivers	Console, GPIO, LEDs, Block devices	`homecore/drivers`
Kernel services	Kernel, Users, Sessions	`homecore/kernel`, `homecore/user`, `homecore/session`
Subsystems	Virtual file system, Filesystems (FAT filesystem, littlefs filesystem), Shell	`homecore/vfs`, `homecore/fs`, `homecore/shell`

The group tree is on the Topics page. Each group page shows its place in the hierarchy. Each header page shows include graphs in both directions. Structures that reference other documented types show a collaboration graph.

Bundled libraries

CMSIS is used only inside the architecture and SoC code; the public API does not expose its types. Its reference is Arm's documentation for the pinned release.

Library	Reference	Used by
CMSIS 6.3.0 Core (`external/cmsis`)	CMSIS-Core (Cortex-M)	NVIC, SysTick, and SCB access in `src/arch`, device headers in `src/soc`
STM32F4 device headers (`external/stm32f4`)	Vendored ST CMSIS device headers; no separate reference	The STM32F407 SoC port
FatFs R0.16 (`external/fatfs`)	FatFs documentation; HomeCore's use is in FAT filesystem	FAT volumes, compiled only for boards that mount one
littlefs v2.11.3 (`external/littlefs`)	README, design; HomeCore's use is in littlefs filesystem	littlefs volumes, compiled only for boards that mount one

G2Basic is built into this site from the pinned submodule commit, so it matches this firmware. Its groups are also listed on the Topics page.

Library	Reference	Used by
G2Basic (`external/g2basic`)	G2Basic API, starting with the Embedding API	The `basic` shell command, which registers `millis()`, `led()`, and `ledget()`

Startup order

main() calls arch_init(), soc_init(), board_init(), dt_init() (generated driver initialization), k_init(), dt_mount_all() (the board's filesystem mounts), and shell_init() in that order, then prints the banner and enters shell_run(). A module may depend only on modules initialized before it. For example, soc_init() registers VFS devices but must not print, because the console is not open until k_init().

Scope

The firmware has no scheduler, privilege separation, authentication, or persistent storage: every mounted volume is a ramdisk formatted at boot. The architecture thread primitives are scaffolding; the SVC and PendSV handlers they depend on currently panic.