#include <hardware.h>

    .module crt0
    .globl  _main

	.area	_HEADER (ABS)
    .org    0x0000
start:
    xor     a
    ld      i, a
    ld      sp, #0x0000
    di
    ;; Init PIO and check for KEY2
    ld      a, #PIO_MODE_3
    out     (PORT_B_CTRL), a
    ld      a, #0x7F
    out     (PORT_B_CTRL), a
    in      a, (PORT_B_DATA)
    and     #0x02               ; is KEY2 pressed? If so, start booloader
    jr      NZ, main
    ;; Load payload (bootloader)
    ld      HL, #0x7000
    ld      DE, #0x8000
    ld      BC, #0x1000
    ldir
    ;; Start bootloader
    jp      0x8000
main:
    call	gsinit
	call	_main
1$:
	halt
	jr	1$

	;; Ordering of segments for the linker.
	.area	_HOME
	.area	_CODE
	.area	_INITIALIZER
	.area   _GSINIT
	.area   _GSFINAL

	.area	_DATA
	.area	_INITIALIZED
	.area	_BSEG
	.area   _BSS
	.area   _HEAP

	.area   _CODE

	.area   _GSINIT
gsinit:
	;; Default-initialized global variables.
    ld      bc, #l__DATA
    ld      a, b
    or      a, c
    jr      Z, zeroed_data
    ld      hl, #s__DATA
    ld      (hl), #0x00
    dec     bc
    ld      a, b
    or      a, c
    jr      Z, zeroed_data
    ld      e, l
    ld      d, h
    inc     de
    ldir
zeroed_data:
	;; Explicitly initialized global variables.
	ld	bc, #l__INITIALIZER
	ld	a, b
	or	a, c
	jr	Z, gsinit_next
	ld	de, #s__INITIALIZED
	ld	hl, #s__INITIALIZER
	ldir

gsinit_next:
	.area   _GSFINAL
	ret