Foenix Kernel Documentation

Foenix Kernel Documentation

Kernel Essentials

On the FMX, the Foenix Kernel resides in bank $39 of the system RAM. It provides for the initialization of the hardware and a certain minimalist level of access to the hardware. Kernel routines are called through a kernel jump table that starts at $00:1000. All kernel routines must be called using the JSL instruction (long, or 24-bit subroutine call), since they all terminate with an RTL. This allows the kernel routines to be called from anywhere in system memory.

Kernel Calls

Name	Address	Description
BOOT	$00:1000	Cold boot routine
PUTC	$00:1018	Print a character to the currently selected channel Register Width Contents A 8 ASCII code of the character to print
PUTS	$00:101C	Print a null-terminated ASCII string to the currently selected channel Register Width Contents B 8 Bank containing the data to print X 16 Address within that bank of the first character to print
SETIN	$00:1038	Set the current input channel used by the GET subroutines Register Width Contents A 8 Input channel to use 0 = Keyboard 1 = COM1 (external serial) 2 = COM2 (internal serial)
SETOUT	$00:103C	Set the current output channel used by the PUT subroutines Register Width Contents A 8 Input channel to use 0 = Screen 1 = COM1 (external serial) 2 = COM2 (internal serial)
GETCHW	$00:104C	Get a character from the input channel. Waits until data received. A=0 and Carry=1 if no data is waiting
GETCHE	$00:1050	Get a character from the input channel and echo to the screen. Wait if data is not ready.
PRINTCR	$00:106C	Print Carriage Return
PRINTH	$00:1078	Print hex value in memory. Register Width Contents B 8 Bank containing the data to print X 16 Address within that bank of the last byte to print Y 16 Number of bytes to print
PRINTAH	$00:1080	Prints hex value in A. Printed value is 2 wide if M flag is 1, 4 wide if M	0
LOCATE	$00:1084	Move the cursor to a new position on the screen. Register Width Contents X 16 The column for the cursor Y 16 The row for the cursor
CSRRIGHT	$00:1090	Move the cursor one position to the right
CSRLEFT	$00:1094	Move the cursor one position to the left
CSRUP	$00:1098	Move the cursor up one row
CSRDOWN	$00:109C	Move the cursor down one row
CSRHOME	$00:10A0	Move the cursor to the upper-left corner
SCROLLUP	$00:10A4	Scroll the screen up one line. Creates an empty line at the bottom.
CLRSCREEN	$00:10B0	Clear the screen
INITCHLUT	$00:10B4	Init character look-up table
INITSUPERIO	$00:10B8	Init Super-IO chip
INITKEYBOARD	$00:10BC	Init keyboard
INITRTC	$00:10C0	Init Real-Time Clock
INITCURSOR	$00:10C4	Init the Cursors registers
INITFONTSET	$00:10C8	Init the Internal FONT Memory
INITGAMMATABLE	$00:10CC	Init the RGB GAMMA Look Up Table
INITALLLUT	$00:10D0	Init the Graphic Engine (Bitmap/Tile/Sprites) LUT
INITVKYTXTMODE	$00:10D4	Init the Text Mode @ Reset Time
INITVKYGRPMODE	$00:10D8	Init the Basic Registers for the Graphic Mode

Console Special Characters

The console routines support several special control codes for both input and output. When the key on the keyboard is pressed, the associated code is returned by the GET routines. If the code is printed through the PUTC or PUTS, the associated operation will be performed on the screen. Note that this means that any graphics characters associated with those code points will not be displayed by PUTC or PUTS. If those characters must be displayed, they would have to be written to the text memory directly.

Code	Name	Keyboard	Description
$08	BS	Backspace	Deletes the character to the left of the cursor, pulling characters in from the right.
$09	TAB	TAB	Moves the cursor right to the next tabulated column (every eight columns).
$0A	LF	N/A	Puts the cursor at column 0 on the next line on the same column.
$0D	CR	RETURN	Creates a newline on the screen. Puts the cursor at column 0 on the next line.
$0F	INS	Insert	Inserts a blank space under the cursor (pushing characters to the right).
$11	UP	Up Arrow	Moves the cursor up one row.
$1D	RIGHT	Right Arrow	Moves the cursor right one column. May wrap to the next line.
$7F	DEL	Delete	Deletes the character under the cursor, pulling characters in from the right.
$91	DOWN	Down Arrow	Moves the cursor down one row. May scroll the screen.
$9D	LEFT	Left Arrow	Moves the cursor left one column.

Special Kernel Variables

The kernel keeps track of several variables. Most kernel variables should be left alone by applications, but there are some which an application might want to set or read.

Start Address	End Address	Name	R/W	Description
$00:000C	$00:000E	SCREENBEGIN	RO	Address of the first character of the text display
$00:000C	$00:000E	SCREENBEGIN	RO	Address of the first character of the text display
$00:000F	$00:0010	COLS_VISIBLE	RW	The number of columns currently displayed
$00:0013	$00:0014	LINES_VISIBLE	RW	The number of rows currently displayed
$00:0017	$00:0018	CURSORPOS	RO	The address of the text character under the cursor
$00:001A	$00:001B	CURSORX	RO	The address of the text character under the cursor
$00:001C	$00:001D	CURSORY	RO	The address of the text character under the cursor
$00:001E		CURCOLOR	RW	The foreground and background colors to be used when printing via PUTC and PUTS
$00:001F	$00:0020	COLORPOS	RO	The address of the text color cell under the cursor