Kernel file I/O subsystem

Kernel filesystem and drive management middleware API extending kernel shell runtime with file mangement commands. More...

Functions
void	_kernel_fio (void)
	Initializes kernel file I/O subsystem.
char	_kernel_cdrive (void)
	Retrieves current active drive letter.
bool	_kernel_unmount (void)
	Unmounts the currently mounted drive.
bool	_kernel_mount (char letter)
	Mounts a drive by letter.
size_t	_kernel_drives (char *drive_lt, size_t nlt)
	Retrieves available drive letters.
void	_kernel_cd (char const *path)
	Changes the current working directory.
void	_kernel_mkdir (char const *path)
	Creates a new directory.
void	_kernel_rmfile (char const *path)
	Removes a file.
void	_kernel_ls (const int argc, const char **argv)
	Lists directory contents.

Detailed Description

Kernel filesystem and drive management middleware API extending kernel shell runtime with file mangement commands.

Function Documentation

_kernel_cd()

void _kernel_cd

(

char const *

path

)

Changes the current working directory.

Parameters

[in]

path

Target directory path.

Precondition

• path must not be NULL.

Changes the active working directory within the kernel filesystem context.

Behavior on invalid path is implementation-defined (e.g., error message output, silent failure, etc.).

Side Effects:

• Updates current working directory state.

Note

Path resolution rules: absolute and relative.

_kernel_cdrive()

char _kernel_cdrive

(

void

)

Retrieves current active drive letter.

Returns

Drive letter of the currently mounted filesystem.

Return values

0	No drive mounted.

Returns the logical drive identifier (e.g., 'A', 'B', 'C').

_kernel_drives()

size_t _kernel_drives	(	char *	drive_lt,
		size_t	nlt
	)

Retrieves available drive letters.

Parameters

[out]	drive_lt	Buffer receiving drive letters.
[in]	nlt	Maximum number of letters to store.

Returns

Number of drive letters written to buffer.

Precondition

• drive_lt must not be NULL if nlt > 0.

Writes up to nlt available drive identifiers into the provided buffer. Letters are not null-terminated unless explicitly handled by the caller.

Note

If the number of available drives exceeds nlt, the list is truncated.

_kernel_fio()

void _kernel_fio

(

void

)

Initializes kernel file I/O subsystem.

Prepares internal filesystem structures, mount tables, and underlying block device interfaces.

Must be called before invoking mount, unmount, or drive-related functions.

Postcondition

• Filesystem subsystem is ready.
• Internal drive state is initialized.

Side Effects:

• Initializes internal static state.
• May access storage hardware.

_kernel_ls()

void _kernel_ls	(	const int	argc,
		const char **	argv
	)

Lists directory contents.

Parameters

[in]	argc	Number of arguments.
[in]	argv	Argument vector.

Precondition

• argv must not be NULL if argc > 0.

Implements directory listing functionality. Arguments may include:

• Target path
• Optional flags.

Intended for invocation from kernel shell.

Side Effects:

• Produces formatted output to console.

_kernel_mkdir()

void _kernel_mkdir

(

char const *

path

)

Creates a new directory.

Parameters

[in]

path

Directory path to create.

Precondition

• path must not be NULL.

Creates a directory at the specified path.

Side Effects:

• Modifies filesystem metadata.

_kernel_mount()

bool _kernel_mount

(

char

letter

)

Mounts a drive by letter.

Parameters

[in]

letter

Logical drive letter to mount.

Return values

true	Mount successful.
false	Mount failed.

Precondition

• letter must correspond to a valid available drive.

Postcondition

• Specified drive becomes active on success.

Side Effects:

• Initializes filesystem structures for the drive.

_kernel_rmfile()

void _kernel_rmfile

(

char const *

path

)

Removes a file.

Parameters

[in]

path

Path to file to remove.

Precondition

• path must not be NULL.

Deletes the specified file from the filesystem.

Removal of directories using this function when not empty will result in access denied.

Side Effects:

• Modifies filesystem structures.

Warning

Operation is irreversible.

_kernel_unmount()

bool _kernel_unmount

(

void

)

Unmounts the currently mounted drive.

Return values

true	Unmount successful.
false	Unmount failed or no drive mounted.

Postcondition

• No active filesystem is mounted on success.

Side Effects:

• Flushes pending filesystem operations.
• Updates internal mount state.