collapseos/apps/zasm/emul/glue.asm

#include "user.inc"
; Glue code for the emulated environment
ZASM_INPUT	.equ	0xa000
ZASM_OUTPUT	.equ	0xd000

jr	init	; 2 bytes
; *** JUMP TABLE ***
jp	strncmp
jp	addDE
jp	upcase

init:
	di
	ld	hl, RAMEND
	ld	sp, hl
	ld	hl, ZASM_INPUT
	ld	de, ZASM_OUTPUT
	call	USER_CODE
	; signal the emulator we're done
	; BC contains the number of written bytes
	ld	a, c
	ld	c, b
	out	(c), a
	halt

#include "core.asm"
zasm: begin parsing with easy pickings Single opcodes that yield constants. "echo ret \| zasm" yields 0xc9. 2019-04-17 06:49:47 +10:00			`#include "user.inc"`
zasm: have a whole kernel in emulation instead of a simple wrapper zasm is going to need to call to kernel code... 2019-04-17 04:26:45 +10:00			`; Glue code for the emulated environment`
			`ZASM_INPUT .equ 0xa000`
			`ZASM_OUTPUT .equ 0xd000`

zasm: reuse code from core 2019-04-17 07:00:19 +10:00			`jr init ; 2 bytes`
			`; * JUMP TABLE *`
			`jp strncmp`
			`jp addDE`
			`jp upcase`

zasm: have a whole kernel in emulation instead of a simple wrapper zasm is going to need to call to kernel code... 2019-04-17 04:26:45 +10:00			`init:`
			`di`
			`ld hl, RAMEND`
			`ld sp, hl`
			`ld hl, ZASM_INPUT`
			`ld de, ZASM_OUTPUT`
zasm: begin parsing with easy pickings Single opcodes that yield constants. "echo ret \| zasm" yields 0xc9. 2019-04-17 06:49:47 +10:00			`call USER_CODE`
zasm: have a whole kernel in emulation instead of a simple wrapper zasm is going to need to call to kernel code... 2019-04-17 04:26:45 +10:00			`; signal the emulator we're done`
			`; BC contains the number of written bytes`
zasm: invert emulator io_write() handling This facilitates debugging. To know the value of `A` at any point, you can do `out (0), a`. The number of bytes in the output will be the value of `A`. 2019-04-18 00:34:30 +10:00			`ld a, c`
			`ld c, b`
zasm: have a whole kernel in emulation instead of a simple wrapper zasm is going to need to call to kernel code... 2019-04-17 04:26:45 +10:00			`out (c), a`
			`halt`

			`#include "core.asm"`