diff options
Diffstat (limited to 'main.asm')
| -rw-r--r-- | main.asm | 196 |
1 files changed, 0 insertions, 196 deletions
diff --git a/main.asm b/main.asm deleted file mode 100644 index 76b84fe..0000000 --- a/main.asm +++ /dev/null @@ -1,196 +0,0 @@ -;;; z80 emulator for 68k calculators - -;;; Astrid Smith -;;; Project started: 2010-06-06 -;;; GPL - -;;; Yes, I use lots of big ascii art. With this much code, you need -;;; something to catch your eye when scrolling through it. I suppose -;;; I'll split it into different files later. - -;;; Registers used: -;;; -;;; A7 68000 stack pointer -;;; A6/epc emulated PC -;;; A5 instruction table base pointer -;;; A4 emulated SP -;;; A3 pointer to flag_storage -;;; A2 -;;; A1 -;;; A0 -;;; -;;; D0 current instruction, scratch for macros -;;; D1 scratch for instructions -;;; D2 further scratch -;;; -;;; -;;; The following have their shadows in the top half of the register -;;; D3/eaf = AF A is in the low byte, F in the high byte (yeah ... speed) -;;; D4/ebc = BC B high, C low -;;; D5/ede = DE D high, E low -;;; D6/ehl = HL H high, L low -;;; -;;; IY is used more often so it's easier to get at. It can be slow -;;; but I don't really care to go to the effort to make it so. -;;; D7/eixy = IX (hi word), IY (low word) - - -;;; emulated I and R are both in RAM - - xdef _ti89 -; xdef _ti92plus - xdef __main -; xdef _tigcc_native - include "../tios.h" - - include "global.inc" - -__main: - movem.l d0-d7/a0-a6,-(sp) - bsr init_load - bsr display_setup - - bsr emu_setup - lea emu_plain_op,a5 - - ;; ... aaaaand we're off! - jsr emu_run - bsr emu_teardown - - bsr display_teardown - bsr unload - movem.l (sp)+,d0-d7/a0-a6 - rts - - include "ports.asm" - include "interrupts.asm" - include "flags.asm" - include "alu.asm" - -emu_setup: - movea.l emu_op_00,a5 - lea emu_run,a2 - lea flag_storage,a3 - move.w #$4000,d1 - bsr deref - move.l a0,epc - move.l a0,esp - - rts - -emu_teardown: - rts - - -;; |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| -;; _ __ ___ ___ _ __ ___ ___ _ __ _ _ ||||||||||||||||||||||||||| -;; | '_ ` _ \ / _ \ '_ ` _ \ / _ \| '__| | | | \\\\\\\\\\\\\\\\\\\\\\\\\\\ -;; | | | | | | __/ | | | | | (_) | | | |_| | ||||||||||||||||||||||||||| -;; |_| |_| |_|\___|_| |_| |_|\___/|_| \__, | /////////////////////////// -;; of the virtual type |___/ ||||||||||||||||||||||||||| -;; =============================================JJJJJJJJJJJJJJJJJJJJJJJJJJJ - - ;; Take a virtual address in d1 and dereference it. Returns the - ;; host address in a0. Destroys a0, d0. -deref: ; 76 cycles + 18 cycles for bsr - ; 20 bytes to inline, saves 34 cycles per call - move.w d1,d0 - andi.w #$3FFF,d0 - movea.w d0,a0 - move.w d1,d0 - andi.w #$C000,d0 ; Can cut this out by pre-masking the table. - rol.w #4,d0 - adda.l deref_table(pc,d0.w),a0 - rts - - EVEN -deref_table: -mem_page_0: dc.l 0 ; bank 0 / 0x0000 -mem_page_1: dc.l 0 ; bank 1 / 0x4000 -mem_page_2: dc.l 0 ; bank 2 / 0x8000 -mem_page_3: dc.l 0 ; bank 3 / 0xc000 - - xdef mem_page_0 - xdef mem_page_1 - xdef mem_page_2 - xdef mem_page_3 - -mem_page_loc_0: dc.b 0 -mem_page_loc_1: dc.b 0 -mem_page_loc_2: dc.b 0 -mem_page_loc_3: dc.b 0 - - xdef mem_page_loc_0 - xdef mem_page_loc_1 - xdef mem_page_loc_2 - xdef mem_page_loc_3 - -pages: dc.l 0 - - xdef pages - - ;; Take a physical address in a0 and turn it into a virtual - ;; address in d0 - ;; Destroys d0 -; XXX AFAICS, a1 is currently a scratch address register, so you can load deref_table in it, and then save some space: -; But you may wish to use it for other purposes in the future, so you needn't integrate that immediately. - - ;; Guessing this is 300 cycles. -underef: - move.l d2,-(a7) - lea deref_table(pc),a1 - move.l a0,d0 - clr.w d2 - sub.l (a1)+,d0 - bmi.s underef_not0 - cmpi.l #$4000,d0 - bmi.s underef_thatsit -underef_not0: - move.l a0,d0 - move.w #$4000,d2 - sub.l (a1)+,d0 - bmi.s underef_not1 - cmpi.l #$4000,d0 - bmi.s underef_thatsit -underef_not1: - move.l a0,d0 - move.w #$8000,d2 - sub.l (a1)+,d0 - bmi.s underef_not2 - cmpi.l #$4000,d0 - bmi.s underef_thatsit -underef_not2: - move.w #$c000,d2 - suba.l (a1)+,a0 - ;; if that fails too, well shit man! - moveq #0,d0 -underef_thatsit: - add.w d2,d0 - move.l (a7)+,d2 - rts - - -;; ========================================================================= -;; instruction instruction instruction ================================ -;; _ _ _ _ ================================ -;; __| (_)___ _ __ __ _| |_ ___| |__ ================================ -;; / _` | / __| '_ \ / _` | __/ __| '_ \ ================================ -;; | (_| | \__ \ |_) | (_| | || (__| | | | ================================ -;; \__,_|_|___/ .__/ \__,_|\__\___|_| |_| ================================ -;; |_| ================================= -;; ========== ======================================================== -;; ========================================================================= - - include "opcodes.asm" - -emu_run: - ;; XXX: make this actually return - DONE - rts - -emu_op_undo_cb: -emu_op_undo_dd: -emu_op_undo_ed: -emu_op_undo_fd: - rts - |