collapseos/emul/forth/glue0.asm

53 lines
1.1 KiB
NASM

; RAM disposition
;
; Because this glue code also serves stage0 which needs HERE to start right
; after the code, we have a peculiar RAM setup here: it lives at the very end
; of the address space, just under RS_ADDR at 0xf000
; Warning: The offsets of native dict entries must be exactly the same between
; glue0.asm and glue1.asm
.equ RAMSTART 0xe800
.equ HERE 0xe700 ; override, in sync with stage1.c
.equ CURRENT 0xe702 ; override, in sync with stage1.c
.equ HERE_INITIAL CODE_END ; override
.inc "ascii.h"
.equ STDIO_PORT 0x00
jp init
.inc "core.asm"
.inc "str.asm"
.equ STDIO_RAMSTART RAMSTART
.equ STDIO_GETC emulGetC
.equ STDIO_PUTC emulPutC
.inc "stdio.asm"
.equ FORTH_RAMSTART STDIO_RAMEND
.inc "forth/main.asm"
.inc "forth/util.asm"
.inc "forth/stack.asm"
.inc "forth/dict.asm"
init:
di
; setup stack
ld sp, 0xffff
call forthMain
halt
emulGetC:
; Blocks until a char is returned
in a, (STDIO_PORT)
cp a ; ensure Z
ret
emulPutC:
out (STDIO_PORT), a
ret
.dw 0 ; placeholder used in glue1.
CODE_END:
.out $ ; should be the same as in glue1