X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/97d31911d562d3bbb07f44e027aa1886ac914a99..6b4e28281b4fa98272bead1eedeea577e8778169:/rom.asm diff --git a/rom.asm b/rom.asm index 640c2b0..02f095b 100644 --- a/rom.asm +++ b/rom.asm @@ -1,25 +1,32 @@ SECTION "a",HOME + main: - ld c, $51 + ld c, $51 ; Note that we are alive. ld a, $FF ld [c],a - ld sp,$DFFF - ld hl,text + ld sp, $DFFF + + ld hl, signon call puts call memtest + + call insntest + call waitsw + jp main -text: +signon: db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0 +; Memory tester: writes h ^ l to all addresses from C000 to DF80. memtest: ld hl,memteststr call puts - ld hl, $C000 + ld hl, $C000 ; Write loop .wr: ld a,h xor l @@ -31,7 +38,7 @@ memtest: cp l jp nz, .wr - ld hl, $C000 + ld hl, $C000 ; Read loop .rd: ld a,h xor l @@ -47,11 +54,11 @@ memtest: cp l jp nz, .rd - ld hl, testokstr + ld hl, testokstr ; Say we're OK call puts ret -.memfail: - @ decrement hl the easy way +.memfail: ; Say we failed (sadface) + ; decrement hl the easy way ld a,[hld] push hl ld hl, failatstr @@ -66,14 +73,14 @@ memtest: ld a, $0D call putc ret - memteststr: db "Testing memory from $C000 to $DF80...",0 testokstr: db " OK!",$0D,$0A,0 failatstr: db " Test failed at $",0 -puthex: + +puthex: ; Put two hex nibbles to the serial console. push af rra rra @@ -92,6 +99,7 @@ puthex: call putc ret +; Wait for switches to be flipped on and off again. waitsw: ld hl,waitswstr call puts @@ -115,6 +123,74 @@ waitsw: waitswstr: db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset.",$0D,$0A,0 +; Core instruction basic acceptance tests. +insntest: + ld hl, .insnteststr + call puts + + ; Test PUSH and POP. + ld b, $12 + ld c, $34 + ld d, $56 + ld e, $78 + push bc + pop de + ld hl, .pushpopfail + ld a, d + cp b + jp nz,.fail + ld a, e + cp c + jp nz,.fail + + ; Test ALU (HL). + ld hl, .ff + ld a, $FF + xor [hl] + ld hl, .xorhlfail + jp nz, .fail + + ; Test CP. + ld hl, .cpfail + ld a, $10 + ld b, $20 + cp b + jp nc,.fail + ld a, $20 + ld b, $10 + cp b + jp c,.fail + + ; Test CPL + ld hl, .cplfail + ld a, $55 + ld b, $AA + cpl + cp b + jp nz,.fail + + ld hl, .ok + call puts + ret +.fail: + call puts + ret +.insnteststr: + db "Testing instructions... ",$0 +.pushpopfail: + db "PUSH/POP test failed.",$0D,$0A,0 +.ff: + db $FF +.xorhlfail: + db "XOR [HL] test failed.",$0D,$0A,0 +.cpfail: + db "CP test failed.",$0D,$0A,0 +.cplfail: + db "CPL test failed.",$0D,$0A,0 +.ok: + db "OK!",$0D,$0A,0 + +; Serial port manipulation functions. putc: push af ld b, 0