ra8_io block-device backend over a caller-owned RAM buffer. More...

#include <stdint.h>
#include "ra8_err.h"
#include "ra8_io_blockdev.h"

Include dependency graph for ra8_io_blockdev_ram.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	ra8_io_blockdev_ram_state_t
	Caller-owned private state for a RAM block device. More...

Functions
ra8_err_t	ra8_io_blockdev_ram_init (ra8_io_blockdev_t bd, ra8_io_blockdev_ram_state_t state, uint8_t *storage, uint32_t block_count, bool read_only)
	Bind a RAM block-device backend into a caller-owned handle.

Detailed Description

ra8_io block-device backend over a caller-owned RAM buffer.

Tag: [Ring 4 / PAL] {World: NS}

The RAM backend treats a flat caller-owned byte buffer as an array of 512-byte logical blocks. It is the reference backend (the simplest correct implementation of ra8_io_blockdev_iface), the substrate for host unit tests, and a usable scratch/ramdisk volume on target (e.g. a small staging area in SRAM, or – via the SDRAM backend's identical model – the 64 MiB external SDRAM window). It erases to zero and needs no erase-before-write.

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

Since: 0.1.0

Definition in file ra8_io_blockdev_ram.h.

Function Documentation

◆ ra8_io_blockdev_ram_init()

ra8_err_t ra8_io_blockdev_ram_init	(	ra8_io_blockdev_t *	bd,
		ra8_io_blockdev_ram_state_t *	state,
		uint8_t *	storage,
		uint32_t	block_count,
		bool	read_only )

nodiscard

Bind a RAM block-device backend into a caller-owned handle.

Records storage/block_count in state, marks it read-only per read_only, and points bd at the RAM vtable with state as its context. No allocation occurs; the caller owns both bd and state.

Parameters

[out]	bd	Handle to bind (zero-initialised by the caller).
[out]	state	Caller-owned backend state to populate.
[in]	storage	Backing buffer of block_count * 512 bytes.
[in]	block_count	Number of 512-byte logical blocks (>= 1).
[in]	read_only	true to reject writes and erases on this device.

Returns: ra8_err_t Error code.

Return values

k_ra8_ok	Backend bound; bd is usable.
k_ra8_err_null_ptr	bd, state, or storage was NULL.
k_ra8_err_invalid_size	block_count was zero.

Precondition: storage covers at least block_count * 512 bytes.; bd and state out-live every call made through the device.

Postcondition: On success bd dispatches to the RAM backend over storage.; On any non-ok return bd and state are left unbound/untouched.

Note: Not thread-safe with respect to the same device.

Since: 0.1.0

Definition at line 262 of file ra8_io_blockdev_ram.c.

References ra8_io_blockdev_ram_state_t::block_count, ra8_io_blockdev_t::ctx, ra8_io_blockdev_t::iface, k_ra8_err_invalid_size, k_ra8_io_ram_min_blocks, k_ra8_ok, RA8_CHECK_NULL_PTR, ra8_io_blockdev_ram_state_t::read_only, s_ram_iface, s_tag, and ra8_io_blockdev_ram_state_t::storage.

Referenced by internal_demo_mount(), internal_demo_probe_fat(), internal_demo_probe_foreign(), internal_demo_run(), internal_demo_run(), internal_swap_run_all(), and ra8_io_blockdev_sdram_init().

Data Structures

Functions

Detailed Description

Function Documentation

◆ ra8_io_blockdev_ram_init()