nesemu/test_roms/cpu_exec_space/source/common/shell.s

332 lines
4.6 KiB
ArmAsm

; Common routines and runtime
; Detect inclusion loops (otherwise ca65 goes crazy)
.ifdef SHELL_INCLUDED
.error "shell.s included twice"
.end
.endif
SHELL_INCLUDED = 1
;**** Special globals ****
; Temporary variables that ANY routine might modify, so
; only use them between routine calls.
temp = <$A
temp2 = <$B
temp3 = <$C
addr = <$E
ptr = addr
.segment "NVRAM"
; Beginning of variables not cleared at startup
nvram_begin:
;**** Code segment setup ****
.segment "RODATA"
; Any user code which runs off end might end up here,
; so catch that mistake.
nop ; in case there was three-byte opcode before this
nop
jmp internal_error
; Move code to $E200 ($200 bytes for text output)
;.segment "DMC"
; .res $2200
; Devcart corrupts byte at $E000 when powering off
.segment "CODE"
nop
;**** Common routines ****
.include "macros.inc"
.include "neshw.inc"
.include "print.s"
.include "delay.s"
.include "crc.s"
.include "testing.s"
.ifdef NEED_CONSOLE
.include "console.s"
.else
; Stubs so code doesn't have to care whether
; console exists
console_init:
console_show:
console_hide:
console_print:
console_flush:
rts
.endif
.ifndef CUSTOM_PRINT
.include "text_out.s"
print_char_:
jsr write_text_out
jmp console_print
stop_capture:
rts
.endif
;**** Shell core ****
.ifndef CUSTOM_RESET
reset:
sei
jmp std_reset
.endif
; Sets up hardware then runs main
run_shell:
sei
cld ; unnecessary on NES, but might help on clone
ldx #$FF
txs
jsr init_shell
set_test $FF
jmp run_main
; Initializes shell
init_shell:
jsr clear_ram
jsr init_wait_vbl ; waits for VBL once here,
jsr wait_vbl_optional ; so only need to wait once more
jsr init_text_out
jsr init_testing
jsr init_runtime
jsr console_init
rts
; Runs main in consistent PPU/APU environment, then exits
; with code 0
run_main:
jsr pre_main
jsr main
lda #0
jmp exit
; Sets up environment for main to run in
pre_main:
.ifndef BUILD_NSF
jsr disable_rendering
setb PPUCTRL,0
jsr clear_palette
jsr clear_nametable
jsr clear_nametable2
jsr clear_oam
.endif
lda #$34
pha
lda #0
tax
tay
jsr wait_vbl_optional
plp
sta SNDMODE
rts
.ifndef CUSTOM_EXIT
exit:
.endif
; Reports result and ends program
std_exit:
sei
cld
ldx #$FF
txs
pha
setb SNDCHN,0
.ifndef BUILD_NSF
setb PPUCTRL,0
.endif
pla
pha
jsr report_result
;jsr clear_nvram ; TODO: was this needed for anything?
pla
jmp post_exit
; Reports final result code in A
report_result:
jsr :+
jmp play_byte
: jsr print_newline
jsr console_show
; 0: ""
cmp #1
bge :+
rts
:
; 1: "Failed"
bne :+
print_str {"Failed",newline}
rts
; n: "Failed #n"
: print_str "Failed #"
jsr print_dec
jsr print_newline
rts
;**** Other routines ****
; Reports internal error and exits program
internal_error:
print_str newline,"Internal error"
lda #255
jmp exit
.import __NVRAM_LOAD__, __NVRAM_SIZE__
; Clears $0-($100+S) and nv_ram_end-$7FF
clear_ram:
lda #0
; Main pages
tax
: sta 0,x
sta $300,x
sta $400,x
sta $500,x
sta $600,x
sta $700,x
inx
bne :-
; Stack except that above stack pointer
tsx
inx
: dex
sta $100,x
bne :-
; BSS except nvram
ldx #<__NVRAM_SIZE__
: sta __NVRAM_LOAD__,x
inx
bne :-
rts
; Clears nvram
clear_nvram:
ldx #<__NVRAM_SIZE__
beq @empty
lda #0
: dex
sta __NVRAM_LOAD__,x
bne :-
@empty:
rts
; Prints filename and newline, if available, otherwise nothing.
; Preserved: A, X, Y
print_filename:
.ifdef FILENAME_KNOWN
pha
jsr print_newline
setw addr,filename
jsr print_str_addr
jsr print_newline
pla
.endif
rts
.pushseg
.segment "RODATA"
; Filename terminated with zero byte.
filename:
.ifdef FILENAME_KNOWN
.incbin "ram:nes_temp"
.endif
.byte 0
.popseg
;**** ROM-specific ****
.ifndef BUILD_NSF
.include "ppu.s"
avoid_silent_nsf:
play_byte:
rts
; Loads ASCII font into CHR RAM
.macro load_ascii_chr
bit PPUSTATUS
setb PPUADDR,$00
setb PPUADDR,$00
setb addr,<ascii_chr
ldx #>ascii_chr
ldy #0
@page:
stx addr+1
: lda (addr),y
sta PPUDATA
iny
bne :-
inx
cpx #>ascii_chr_end
bne @page
.endmacro
; Disables interrupts and loops forever
.ifndef CUSTOM_FOREVER
forever:
sei
lda #0
sta PPUCTRL
: beq :-
.res $10,$EA ; room for code to run loader
.endif
; Default NMI
.ifndef CUSTOM_NMI
zp_byte nmi_count
nmi:
inc nmi_count
rti
; Waits for NMI. Must be using NMI handler that increments
; nmi_count, with NMI enabled.
; Preserved: X, Y
wait_nmi:
lda nmi_count
: cmp nmi_count
beq :-
rts
.endif
; Default IRQ
.ifndef CUSTOM_IRQ
irq:
bit SNDCHN ; clear APU IRQ flag
rti
.endif
.endif