ra8_io_stream_uart.c File Reference

UART/SCI byte-stream sink – polled writes through ra8_sci. More...

#include "ra8_io_stream_uart.h"
#include <stdint.h>
#include "ra8_attributes.h"
#include "ra8_check.h"
#include "ra8_err.h"
#include "ra8_io_stream_backend.h"
#include "ra8_sci.h"

Include dependency graph for ra8_io_stream_uart.c:

Go to the source code of this file.

Functions
static ra8_err_t	internal_uart_write (void *ctx, const uint8_t *buf, uint32_t len, uint32_t *out_written)
	UART sink: write all bytes out of the SCI channel by polling.
static ra8_err_t	internal_uart_flush (void *ctx)
	UART sink: drain the SCI transmit shift register.
ra8_err_t	ra8_io_stream_uart_init (ra8_io_stream_t *s, ra8_io_stream_uart_state_t *state, uint8_t channel)
	Bind a UART stream sink into a caller-owned stream handle.

Variables
static const char *const	s_tag = "ra8_io_stream_uart"
	Module log tag.
static const ra8_io_stream_iface_t	s_uart_iface
	UART stream sink vtable.

Detailed Description

UART/SCI byte-stream sink – polled writes through ra8_sci.

Tag

[Ring 4 / PAL] {World: NS}

Thin wrapper binding ra8_io_stream_iface to ra8_sci_write_polling / ra8_sci_flush. Touches no raw MMIO – the ra8_sci driver owns the HUM citations.

Copyright

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

Definition in file ra8_io_stream_uart.c.

Function Documentation

internal_uart_flush()

ra8_err_t internal_uart_flush ( void * ctx )

static

UART sink: drain the SCI transmit shift register.

Forwards to ra8_sci_flush so a caller can guarantee the line is on the wire before sleeping or asserting a panic.

Parameters

[in]

ctx

UART sink state (as a void cookie).

Returns

ra8_err_t Error code.

Return values

k_ra8_ok	Transmit drained.
k_ra8_err_null_ptr	ctx was NULL.
k_ra8_err_*	Propagated from ra8_sci_flush.

Precondition

ctx is a populated UART sink state.

The SCI channel is initialised.

Postcondition

On success the shift register is empty.

No sink state is mutated.

Note

Not thread-safe with respect to the same channel.

Since

0.1.0

Definition at line 95 of file ra8_io_stream_uart.c.

References ra8_io_stream_uart_state_t::channel, RA8_CHECK_NULL_PTR, RA8_INTERNAL, ra8_sci_flush(), and s_tag.

internal_uart_write()

ra8_err_t internal_uart_write ( void * ctx, const uint8_t * buf, uint32_t len, uint32_t * out_written )

static

UART sink: write all bytes out of the SCI channel by polling.

Forwards to ra8_sci_write_polling. On success every byte was shifted out, so the accepted count equals len.

Parameters

[in]	ctx	UART sink state (as a void cookie).
[in]	buf	Source bytes.
[in]	len	Number of bytes to send.
[out]	out_written	Accepted byte count, or NULL.

Returns

ra8_err_t Error code.

Return values

k_ra8_ok	All bytes sent.
k_ra8_err_null_ptr	ctx or buf was NULL.
k_ra8_err_*	Propagated from ra8_sci_write_polling.

Precondition

ctx is a populated UART sink state.

The SCI channel is initialised.

Postcondition

On success all len bytes were transmitted.

*out_written (when provided) equals len on success.

Note

Not thread-safe with respect to the same channel.

Since

0.1.0

Definition at line 57 of file ra8_io_stream_uart.c.

References ra8_io_stream_uart_state_t::channel, k_ra8_ok, RA8_CHECK_NULL_PTR, ra8_sci_write_polling(), and s_tag.

Referenced by priv_ra8_esp_hosted_osi_bind_absent().

ra8_io_stream_uart_init()

ra8_err_t ra8_io_stream_uart_init ( ra8_io_stream_t * s, ra8_io_stream_uart_state_t * state, uint8_t channel )

nodiscard

Bind a UART stream sink into a caller-owned stream handle.

Parameters

[out]	s	Stream handle to bind (zero-initialised by the caller).
[out]	state	Caller-owned sink state to populate.
[in]	channel	SCI channel index to write to.

Returns

ra8_err_t Error code.

Return values

k_ra8_ok	Sink bound; s is usable.
k_ra8_err_null_ptr	s or state was NULL.

Precondition

The SCI channel has been initialised with ra8_sci_init.

s and state out-live every call made through the stream.

Postcondition

On success s writes bytes out of channel.

On any non-ok return s and state are left unbound/untouched.

Note

Not thread-safe with respect to the same stream.

Since

0.1.0

Definition at line 109 of file ra8_io_stream_uart.c.

References ra8_io_stream_uart_state_t::channel, RA8_CHECK_NULL_PTR, ra8_io_stream_bind(), s_tag, and s_uart_iface.

Referenced by main(), and ra8_board_console_stream().

Variable Documentation

s_tag

const char* const s_tag = "ra8_io_stream_uart"

static

Module log tag.

Definition at line 28 of file ra8_io_stream_uart.c.

s_uart_iface

const ra8_io_stream_iface_t s_uart_iface

static

Initial value:

                                                = {
  .write = internal_uart_write,
  .flush = internal_uart_flush,
}

UART stream sink vtable.

Definition at line 103 of file ra8_io_stream_uart.c.

Referenced by ra8_io_stream_uart_init().