Host-side keystroke FIFO implementation (see board_input.h). More...

#include "board_input.h"
#include <stdint.h>

Include dependency graph for board_input.c:

Enumerations
enum	board_input_cfg_t : uint32_t { k_key_ring_cap = 64U }
	Keystroke ring geometry. More...

Functions
void	board_input_push_key (char ch)
	Push one keystroke byte into the input FIFO.
bool	board_input_pop_key (char *out)
	Pop the oldest buffered keystroke, if any.

Variables
static char	s_ring [k_key_ring_cap]
	Keystroke ring storage.
static uint32_t	s_head
	Read cursor (oldest byte).
static uint32_t	s_tail
	Write cursor (next free).

Detailed Description

Host-side keystroke FIFO implementation (see board_input.h).

A fixed-size ring buffer. The window's keyDown handler and the --keys flag both push through board_input_push_key; the run loop drains via board_input_pop_key into the console UART RX. Single-threaded harness use.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file board_input.c.

Enumeration Type Documentation

◆ board_input_cfg_t

enum board_input_cfg_t : uint32_t

Keystroke ring geometry.

Enumerator
k_key_ring_cap	Ring capacity (one slot is the full/empty guard).

Definition at line 20 of file board_input.c.

Function Documentation

◆ board_input_pop_key()

bool board_input_pop_key ( char * out )

Pop the oldest buffered keystroke, if any.

Parameters

[out] out Receives one keystroke byte when true is returned.

Returns: true if a byte was dequeued (and consumed); false if empty / out is NULL.

Note: Not thread-safe; single-threaded harness use.

Since: 0.1.0

Pop the oldest buffered keystroke, if any; this step is contained within the board input model and uses bounded caller or module-owned storage.

Return values

true	The board input pop key condition holds or completed successfully; false otherwise.

Precondition: Arguments satisfy the ranges documented for board input pop key.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board input model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Definition at line 37 of file board_input.c.

References k_key_ring_cap, s_head, s_ring, and s_tail.

Referenced by internal_run_loop_tick_inputs().

◆ board_input_push_key()

void board_input_push_key ( char ch )

Push one keystroke byte into the input FIFO.

Appends ch to the ring; on overflow the newest key is dropped (the firmware draining the FIFO is the slow consumer). Called by the window keyDown handler and by the --keys injector alike, so both reach the UART through one path.

Parameters

[in] ch Keystroke byte to enqueue.

Returns: Nothing.

Note: Not thread-safe; single-threaded harness use.

Since: 0.1.0

Precondition: Arguments satisfy the ranges documented for board input push key.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board input model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Definition at line 28 of file board_input.c.

References k_key_ring_cap, s_head, s_ring, and s_tail.

Referenced by internal_main_feed_inputs().