interpreter.h

/*
  Kinesis ergonomic keyboard firmware replacement

  Copyright 2012 Chris Andreae (chris (at) andreae.gen.nz)

  Licensed under the GNU GPL v2 (see GPL2.txt).

  See Kinesis.h for keyboard hardware documentation.

  ==========================

  If built for V-USB, this program includes library and sample code from:
	 V-USB, (C) Objective Development Software GmbH
	 Licensed under the GNU GPL v2 (see GPL2.txt)

  ==========================

  If built for LUFA, this program includes library and sample code from:
			 LUFA Library
	 Copyright (C) Dean Camera, 2011.

  dean [at] fourwalledcubicle [dot] com
		   www.lufa-lib.org

  Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)

  Permission to use, copy, modify, distribute, and sell this
  software and its documentation for any purpose is hereby granted
  without fee, provided that the above copyright notice appear in
  all copies and that both that the copyright notice and this
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
  software without specific, written prior permission.

  The author disclaim all warranties with regard to this
  software, including all implied warranties of merchantability
  and fitness.  In no event shall the author be liable for any
  special, indirect or consequential damages or any damages
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

#ifndef __INTERPRETER_H
#define __INTERPRETER_H

#include <stdint.h>

#include "extrareport.h"
#include "Descriptors.h"

#ifndef DEBUG // not used by interpreter debug harness
#include "keystate.h"
#endif

typedef enum _bytecode {
	// local variable store
	BSTORE   = 0,
	BSTORE_0 = 1,
	BSTORE_1,
	BSTORE_2,
	BSTORE_3,
	SSTORE   = 5,
	SSTORE_0 = 6,
	SSTORE_1,
	SSTORE_2,
	SSTORE_3,
	
	// local variable load
	BLOAD    = 10,
	BLOAD_0  = 11,
	BLOAD_1,
	BLOAD_2,
	BLOAD_3,
	SLOAD    = 15,
	SLOAD_0  = 16,
	SLOAD_1,
	SLOAD_2,
	SLOAD_3,

	// global variable store
	GBSTORE = 20,
	GBLOAD  = 21,
	GSSTORE = 22,
	GSLOAD  = 23,

	// immediate
	BCONST   = 24,
	BCONST_0 = 25,
	BCONST_1,
	BCONST_2,
	BCONST_3,
	SCONST   = 29,
	SCONST_0 = 30,
	SCONST_1,
	SCONST_2,
	SCONST_3,

	DUP   = 34,
	DUP2  = 35,
	POP   = 36,
	POP2  = 37,
	SWAP  = 38,

	// Arithmetic
	BADD      = 48,
	BSUBTRACT = 49,
	BMULTIPLY = 50,
	BDIVIDE   = 51,
	BMOD      = 52,
	BAND	  = 53,
	BOR		  = 54,
	BXOR	  = 55,
	BNOT	  = 56,
	BCMP	  = 57,
	BLSHIFT   = 58,
	BRSHIFT   = 59,
	SADD	  = 60,
	SSUBTRACT = 61,
	SMULTIPLY = 62,
	SDIVIDE   = 63,
	SMOD	  = 64,
	SAND	  = 65,
	SOR		  = 66,
	SXOR	  = 67,
	SNOT	  = 68,
	SCMP	  = 69,
	SLSHIFT   = 70,
	SRSHIFT   = 71,

	// Type conversion
	B2S = 72,
	S2B = 73,

	// control flow
	IFEQ   = 74,
	IFNE   = 75,
	IFLT   = 76,
	IFGT   = 77,
	IFGE   = 78,
	IFLE   = 79,
	GOTO   = 80,
	NOP    = 81,
	CALL   = 82,
	BRET   = 83,
	SRET   = 84,
	RET    = 85,
	VMEXIT = 86,

	// System calls:
	// keyboard:

	// void pressKey(byte h_keycode): causes the argument HID (not physical) key to be pressed. Does
	// not return until a report has been sent
	PRESSKEY = 87,

	// void releaseKey(byte h_keycode): causes the argument HID key to be released, if it was being
	// pressed by this program.
	RELEASEKEY = 88,

	// void checkKey(byte h_keycode): checks the current state for any key mapped to the argument
	// HID keycode, returns 1/0
	CHECKKEY = 89,

	// void checkPhysKey(byte p_keycode): checks the current state for the argument physical key. 0
	// means the the key that triggered the program. returns 1/0
	CHECKPHYSKEY = 90,

	// byte waitKey(byte key, short timeout): causes execution to be stopped until a key mapped to
	// the argument HID keycode (or 0 for any key) has been pressed, or the argument time has
	// elapsed (0 for indefinite).  Returns the mapped HID keycode of the first pressed key (not
	// necessarily the argument) or 0 if timed out.
	WAITKEY = 91,

	// like waitkey, but takes an argument physical keycode or 0 for the key that
	// triggered the program. Returns 1 if pressed or 0 if timed out.
	WAITPHYSKEY = 92,

	// general
	// void delay(short ms): causes execution to be stopped until arg1 ms elapsed
	DELAY = 95,

	// short getUptimeMS(): returns uptime in ms truncated to signed short int
	GETUPTIMEMS = 96,

	// short getuptime(): returns uptime in seconds truncated to signed short int
	GETUPTIME = 97,

	// void buzz(short time): requests that the buzzer be run for the next time ms
	BUZZ = 98,

	// void buzzAt(short time, byte freq): runs the buzzer at 1/((unsigned byte)freq * 4e-6) for short ms.
	BUZZAT = 99,

	// void moveMouse(byte x, byte y): Moves the mouse by the
	// requested offset next time the mouse report is sent. Does not
	// return until report has been sent.
	MOVEMOUSE = 100,

	// void pressMouseButtons(byte buttonMask): Presses the mouse
	// buttons specified by buttonMask (bits 1-5 = buttons 1-5). Does
	// not return until report has been sent.
	PRESSMOUSEBUTTONS = 101,

	// void releaseMouseButtons(byte buttonMask): Releases the mouse
	// buttons specified by buttonMask (bits 1-5 = buttons 1-5) if
	// they are pressed by this program. Does not return until report
	// has been sent.
	RELEASEMOUSEBUTTONS = 102,

} bytecode;

typedef int8_t vbyte;
typedef int16_t vshort;

typedef struct __attribute__((__packed__)) _method { // Lives in EEPROM
	uint8_t nargs;
	uint8_t nlocals;
	uint16_t code_offset;
} method;

typedef struct __attribute__((__packed__)) _program { // lives in EEPROM
	uint8_t nglobals;
	uint8_t nmethods;
	method methods[1]; // ...
} program;


// stack organization:
// [ globals | stackframe1 | stackdata1 | stackframe2 | stackdata2 ... ]

typedef struct __attribute__((__packed__)) _stack_frame { // stack frames live within the stack
	const bytecode* return_addr;
	vbyte* return_stack;  // TODO: save space by making these single byte offsets
	struct _stack_frame* previous_frame;
	vbyte locals[1];
} stack_frame;

#ifdef DEBUG
#define STACK_SIZE 1024 // bytes
#else
#define STACK_SIZE 96 // bytes
#endif
// globals
typedef struct __attribute__((__packed__)) _vmstate {
	enum __attribute__((__packed__)) { VMSTOPPED, VMCRASHED, VMNOPROGRAM, VMRUNNING, VMWAITREPORT, VMWAITMOUSEREPORT, VMDELAY, VMWAITKEY, VMWAITPHYSKEY } state;
	// uptimems at which our current delay or waitkey ends
	uint32_t delay_end_ms;
	// key that we're waiting for
	hid_keycode wait_key;
	// the physical key that triggered this program
	logical_keycode trigger_lkey;

	ExtraKeyboardReport keyboardreport;
	MouseReport_Data_t mousereport;

	const program* program;
	const bytecode* code;

	const bytecode* ip;

	vbyte* stack_top;
	stack_frame* current_frame; // points within stack

	vbyte stack[STACK_SIZE];
} vmstate;

/**
 * Initialize the virtual machines: load programs from eeprom memory and reset each VM to default halted state.
 */
void vm_init(void);

/**
 * Start or restart a VM that has exit or crashed
 */
uint8_t vm_start(uint8_t vm_idx, logical_keycode trigger_lkey);

/**
 * Execute the next instruction in each running VM
 */
void vm_step_all(void);

/**
 * add the pressed key status of every running VM to an existing keyboard report
 */
void vm_append_KeyboardReport(KeyboardReport_Data_t* report);

/**
 * Add the mouse status of every running VM to an existing keyboard report
 */
void vm_append_MouseReport(MouseReport_Data_t* report);

#endif // __INTERPRETER_H