ra8_io block-device backend over the external 64 MiB SDRAM window. More...

#include <stdint.h>
#include "ra8_err.h"
#include "ra8_io_blockdev.h"
#include "ra8_io_blockdev_ram.h"

Include dependency graph for ra8_io_blockdev_sdram.h:

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Functions
ra8_err_t	ra8_io_blockdev_sdram_init (ra8_io_blockdev_t bd, ra8_io_blockdev_ram_state_t state, uint32_t block_count)
	Bring up the SDRAM controller and bind it as a volatile ramdisk.

Detailed Description

ra8_io block-device backend over the external 64 MiB SDRAM window.

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

The SDRAM backend is a volatile ramdisk: once the SDRAM controller is brought up, the external 64 MiB window at k_ra8_sdram_base_addr is plain memory, so this backend reuses the RAM backend's vtable and state (ra8_io_blockdev_ram_state_t) verbatim. It treats the SDRAM window as an array of 512-byte logical blocks, erases to zero, and needs no erase-before-write. Contents do not survive a power cycle.

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

Since: 0.1.0

Definition in file ra8_io_blockdev_sdram.h.

Function Documentation

◆ ra8_io_blockdev_sdram_init()

ra8_err_t ra8_io_blockdev_sdram_init	(	ra8_io_blockdev_t *	bd,
		ra8_io_blockdev_ram_state_t *	state,
		uint32_t	block_count )

nodiscard

Bring up the SDRAM controller and bind it as a volatile ramdisk.

Validates block_count against the 64 MiB SDRAM window, initialises the SDRAM controller via ra8_sdramc_init, then delegates to ra8_io_blockdev_ram_init using the SDRAM base address as the backing buffer (writable, never read-only). The reused ra8_io_blockdev_ram_state_t is caller-owned and must out-live every call made through the device.

Parameters

[out]	bd	Handle to bind (zero-initialised by the caller).
[out]	state	Caller-owned RAM-backend state to populate.
[in]	block_count	Number of 512-byte logical blocks (>= 1, <= window).

Returns: ra8_err_t Error code.

Return values

k_ra8_ok	Controller up and backend bound; bd is usable.
k_ra8_err_null_ptr	bd or state was NULL.
k_ra8_err_invalid_size	block_count was zero or exceeds the window.

Precondition: bd and state out-live every call made through the device.; The SDRAM pins/clocks are configured for ra8_sdramc_init to succeed.

Postcondition: On success bd dispatches to the RAM backend over the SDRAM window.; 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 69 of file ra8_io_blockdev_sdram.c.

References internal_sdram_max_blocks(), k_ra8_err_invalid_size, k_ra8_io_sdram_min_blocks, k_ra8_sdram_base_addr, RA8_CHECK_NULL_PTR, ra8_io_blockdev_ram_init(), RA8_RETURN_ON_ERROR, ra8_sdramc_init(), and s_tag.

Referenced by demo_run(), and internal_demo_run().

Functions

Detailed Description

Function Documentation

◆ ra8_io_blockdev_sdram_init()