Classes
struct	cbmimage_i_bam_selector_s
	BAM Selector . More...

struct	cbmimage_fileimage_functions_s
	BAM counter selector . More...

Typedefs
typedef enum cbmimage_BAM_state_e	cbmimage_BAM_state
	state of the BAM

typedef struct cbmimage_i_bam_selector_s	cbmimage_i_bam_selector
	BAM Selector .

typedef cbmimage_i_bam_selector	cbmimage_i_bam_counter_selector
	BAM counter selector .

typedef struct cbmimage_fileimage_functions_s	cbmimage_fileimage_functions
	BAM counter selector .

Enumerations
enum	cbmimage_BAM_state_e { BAM_UNKNOWN , BAM_REALLY_FREE , BAM_FREE , BAM_USED , BAM_DOES_NOT_EXIST }
	state of the BAM More...

Functions
static uint8_t	reverse_bit_order (uint8_t input)

static int	cbmimage_i_countbits (bam_mask_t value)

void	cbmimage_i_init_bam_selector (cbmimage_image_settings settings, cbmimage_i_bam_selector selector, size_t selector_count)

static int	cbmimage_i_get_right_selector (cbmimage_image_settings settings, cbmimage_i_bam_selector selector, size_t selector_count, uint8_t track)

static void	cbmimage_i_bam_print (bam_mask_t mask)

static int	cbmimage_i_check_max_bam_of_track (cbmimage_image_settings *settings, uint16_t track, bam_mask_t mask)

static int	cbmimage_i_get_bam_of_track (cbmimage_image_settings settings, uint8_t track, bam_mask_t mask)

static uint16_t	cbmimage_i_get_bam_counter_of_track (cbmimage_image_settings *settings, uint8_t track)

int	cbmimage_i_bam_check_really_unused (cbmimage_image_settings *settings, cbmimage_blockaddress block)

cbmimage_BAM_state	cbmimage_bam_get (cbmimage_fileimage *image, cbmimage_blockaddress block)
	get the unused/used state of a block in the BAM

int	cbmimage_bam_check_consistency (cbmimage_fileimage *image)
	check the consistency of a BAM

int	cbmimage_get_blocks_free (cbmimage_fileimage *image)
	get the count of blocks free

int	cbmimage_bam_get_free_on_track (cbmimage_fileimage *image, uint8_t track)
	get the blocks free on a specific track

Detailed Description

Typedef Documentation

◆ cbmimage_fileimage_functions

typedef struct cbmimage_fileimage_functions_s cbmimage_fileimage_functions

BAM counter selector .

this type contains helper functions that perform image format specific operations on an image type

◆ cbmimage_i_bam_counter_selector

typedef cbmimage_i_bam_selector cbmimage_i_bam_counter_selector

BAM counter selector .

A bam_counter selector is almost the same as a BAM selector. Instead of pointing to the bit map of the BAM, though, it points to the location where the number of free blocks on the track is located.

In most cases, these are located directly before the bitmap, so the BAM selector could be used. However, in the case of the 2nd side of a D71 image, this is not true; that's why this own type of selector is needed here.

Remarks

see also cbmimage_i_bam_selector_s
data_count is unused and must be 0.

◆ cbmimage_i_bam_selector

typedef struct cbmimage_i_bam_selector_s cbmimage_i_bam_selector

BAM Selector .

This type describes where the BAM entries (that is, the bitmap part of the BAM) are located on disk. This way, the code that handles BAM entries is generic, and only the initialization of the BAM selector has to be image specific.

In case the BAM is stored in multiple blocks (or in the same block, but at different locations), an array of BAM selectors has to be used, with every selector describing one location of the BAM entries

Remarks

see also cbmimage_i_bam_counter_selector

Enumeration Type Documentation

◆ cbmimage_BAM_state_e

enum cbmimage_BAM_state_e

state of the BAM

Enumerator
BAM_UNKNOWN	BAM state of block is unknown.
BAM_REALLY_FREE	BAM state of block is "free", and the block does not contain any data.
BAM_FREE	BAM state of block is "free", but the block contains some data.
BAM_USED	BAM state of block is "used".
BAM_DOES_NOT_EXIST	the block does not exist

Function Documentation

◆ cbmimage_bam_check_consistency()

int cbmimage_bam_check_consistency ( cbmimage_fileimage * image )

check the consistency of a BAM

Parameters

[in] image pointer to the image data

Returns

0 if the BAM is consistent
!= 0 if not

Remarks

A BAM is consistent if the following applies:

no track has free blocks for sectors that do not exist
the free block count of a track is the same as the number of free sectors
(i.e., the number fits the bitmap)

Todo: How should details be given to the caller?

◆ cbmimage_bam_get()

cbmimage_BAM_state cbmimage_bam_get	(	cbmimage_fileimage *	image,
		cbmimage_blockaddress	block )

get the unused/used state of a block in the BAM

Parameters

[in]	image	pointer to the image data
[in]	block	the address of the block to check

Returns

the BAM state (BAM_REALLY_FREE, BAM_USED, BAM_FREE).

Remarks

If the block does not exist, the result is unspecified. Thus, be careful that you provide a valid track.

Todo: : optimize. Getting the whole track just to extract one byte is a little bit of overhead. This can be optimized

◆ cbmimage_bam_get_free_on_track()

int cbmimage_bam_get_free_on_track	(	cbmimage_fileimage *	image,
		uint8_t	track )

get the blocks free on a specific track

Parameters

[in]	image	pointer to the image data
[in]	track	the track number for which the number of tracks is requested

Returns: count of free blocks on this track

◆ cbmimage_get_blocks_free()

int cbmimage_get_blocks_free ( cbmimage_fileimage * image )

get the count of blocks free

Parameters

[in] image pointer to the image data

Returns: count of free blocks on this image

◆ cbmimage_i_bam_check_really_unused()

int cbmimage_i_bam_check_really_unused	(	cbmimage_image_settings *	settings,
		cbmimage_blockaddress	block )

check if a block is really unused, that is, it's value is the same as after formatting

Parameters

[in]	settings	pointer to the image data internal settings
[in]	block	the address of the block to check

Returns

0 if the block is used
!= 0 otherwise

Remarks

If the block does not exist, the result is unspecified. Thus, be careful that you provide a valid track.
It is tested if the block is all "0" (0x00, 0x00, 0x00, ..., 0x00) OR if it is all but the first value "1" (0x??, 0x01, 0x01, ..., 0x01) The second scheme is used in the 1541 for no apparant reason. The 0x?? is often 0x4B (the result of the GCR conversion), but not on the first track!

◆ cbmimage_i_bam_print()

static void cbmimage_i_bam_print ( bam_mask_t mask )

static

output a BAM bitmap

Parameters

[in] mask the BAM map to output

◆ cbmimage_i_check_max_bam_of_track()

static int cbmimage_i_check_max_bam_of_track	(	cbmimage_image_settings *	settings,
		uint16_t	track,
		bam_mask_t	mask )

static

check the BAM bitmap of a specific track

Parameters

[in]	settings	pointer to the image data internal settings
[in]	track	the track for which to find the BAM bitmap
[in]	mask	the BAM map to check

Returns

0 on success
-1 on error

Remarks

The BAM bitmap is invalid if

the track does not exist, or
sectors that do not exist are marked are available

◆ cbmimage_i_countbits()

static int cbmimage_i_countbits ( bam_mask_t value )

static

count the number of "1" bits

Parameters

[in] value values of which to count the number of "1" bits

Returns: The number of "1" bits in value

Remarks

An extremly simple algorithm is used, just counting the bits in a loop.

◆ cbmimage_i_get_bam_counter_of_track()

static uint16_t cbmimage_i_get_bam_counter_of_track	(	cbmimage_image_settings *	settings,
		uint8_t	track )

static

get the BAM counter of a specific track

Parameters

[in]	settings	pointer to the image data internal settings
[in]	track	the track for which to find the BAM map

Returns

the number of free blocks on this track according to the BAM

Remarks

If an error occurs (track does not exist), the return value is 0. Note that this cannot be distinguished from an empty BAM map, so be careful that you provide a valid track.

◆ cbmimage_i_get_bam_of_track()

static int cbmimage_i_get_bam_of_track	(	cbmimage_image_settings *	settings,
		uint8_t	track,
		bam_mask_t *	mask )

static

get the BAM bitmap of a specific track

Parameters

[in]	settings	pointer to the image data internal settings
[in]	track	the track for which to find the BAM bitmap
[in,out]	mask	pointer to a bam_mask_t that will contain the BAM map on exit

Returns

0 on success
-1 on error

◆ cbmimage_i_get_right_selector()

static int cbmimage_i_get_right_selector	(	cbmimage_image_settings *	settings,
		cbmimage_i_bam_selector *	selector,
		size_t	selector_count,
		uint8_t	track )

static

get the BAM selector that matches a specific track

Parameters

[in]	settings	pointer to the image data internal settings
[in]	selector	array of the selectors
[in]	selector_count	number of elements in the selector array
[in]	track	the track for which to find the BAM selector

Returns

The index of the selector to which the track belongs
If an error occurs (track does not exist), the return value is -1

◆ cbmimage_i_init_bam_selector()

void cbmimage_i_init_bam_selector	(	cbmimage_image_settings *	settings,
		cbmimage_i_bam_selector *	selector,
		size_t	selector_count )

init a BAM selector

Parameters

[in]	settings	pointer to the image data internal settings
[in,out]	selector	array of the selectors to initialize
[in]	selector_count	number of elements in the selector array

Remarks

The LBA part of the block address is initialized from the T/S values
The buffer pointer is set to the right location inside of the image

◆ reverse_bit_order()

static uint8_t reverse_bit_order ( uint8_t input )

static

reverse the bit order in the byte

Parameters

[in] input byte value of which the bit order should be reversed

Returns: the byte value with the reversed bits

Remarks

An extremly simple algorithm is used, just shifting out a bit from the input and shifting it in into the output in reverse order.

Todo: reversing can be optimized, for example by using a lookup table

Classes

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ cbmimage_fileimage_functions

◆ cbmimage_i_bam_counter_selector

◆ cbmimage_i_bam_selector

Enumeration Type Documentation

◆ cbmimage_BAM_state_e

Function Documentation

◆ cbmimage_bam_check_consistency()

◆ cbmimage_bam_get()

◆ cbmimage_bam_get_free_on_track()

◆ cbmimage_get_blocks_free()

◆ cbmimage_i_bam_check_really_unused()

◆ cbmimage_i_bam_print()

◆ cbmimage_i_check_max_bam_of_track()

◆ cbmimage_i_countbits()

◆ cbmimage_i_get_bam_counter_of_track()

◆ cbmimage_i_get_bam_of_track()

◆ cbmimage_i_get_right_selector()

◆ cbmimage_i_init_bam_selector()

◆ reverse_bit_order()