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#include <hardware.h>
.module boot
.globl _main
.area _HEADER (ABS)
.org 0x0000
rst_0:
di
jr start
.org 0x0008
rst_1:
.org 0x0010
rst_2:
.org 0x0018
rst_3:
.org 0x0020
rst_4:
.org 0x0028
rst_5:
.org 0x0030
rst_6:
.org 0x0038
rst_7:
.org 0x0040
start:
xor a
ld i, a
ld sp, #0x0000
;; Init PIO
ld a, #PIO_MODE_3
out (PORT_B_CTRL), a
ld a, #0x7F
out (PORT_B_CTRL), a
;; Check keys
in a, (PORT_B_DATA)
bit KEY2_BIT, a
jr z, development_mode
bit KEY3_BIT, a
jr z, command_line
;; No payload selected; try to load os from sd card
jr temporary_payload
main:
call gsinit
call _main
1$:
halt
jr 1$
;;; ROM Payloads
development_mode:
ld hl, #0x1000 ; src
ld de, #0x8000 ; dest
ld bc, #0x1000 ; size
ldir
jp 0x8000
command_line:
ld hl, #0x2000 ; src
ld de, #0x8000 ; dest
ld bc, #0x1000 ; size
ldir
jp 0x8000
temporary_payload:
ld hl, #0x3000 ; src
ld de, #0x8000 ; dest
ld bc, #0x5000 ; size
ldir
jp 0x8000
;;; Interrupt table
.org 0x0100
_ctc0_isr_ptr::
.dw #0
_ctc1_isr_ptr::
.dw #0
_ctc2_isr_ptr::
.dw #0
_ctc3_isr_ptr::
.dw #0
_port_a_isr_ptr::
.dw #0
_port_b_isr_ptr::
.dw #0
_rx_isr_ptr::
.dw #0
;; 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
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