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6502bench/SourceGen/SGTestData/Expected/20040-address-changes_Merlin32.S
Andy McFadden 99cd0d3ac1 Improve handling of C64 PRG header
C64 PRG files are pretty common.  Their salient feature is that they
start with a 16-bit value that is used as the load address.  The
value is commonly generated by the assembler itself, rather than
explicitly added to the source file.

Not all assemblers know what a PRG file is, and some of them handle
it in ways that are difficult to guarantee in SourceGen.  ACME adds
the 16-bit header when the output file name ends in ".prg", cc65
uses a modified config file, 64tass uses a different command-line
option, and Merlin 32 has no idea what they are.

This change adds PRG file detection and handling to the 64tass code
generator.  Doing so required making a few changes to the gen/asm
interfaces, because we now need to have the generator pass additional
flags to the assembler, and sometimes we need code generation to
start somewhere other than offset zero.  Overall the changes were
pretty minor.

The 20042-address-changes test needed a 6502-only variant.  A new test
(20040-address-changes) has been added and given a PRG header.  As
part of this change the 65816 variant was changed to use addresses
in bank 2, which uncovered a code generation bug that this change
also fixes.

The 64tass --long-address flag doesn't appear to be necessary for
files <= 65536 bytes long, so we no longer emit it for those.

(issue #90)
2020-10-17 16:45:13 -07:00

108 lines
1.9 KiB
ArmAsm

org $1000
dw $1000 ;PRG-style header
org $1000
jsr L1100
jsr L1107
jmp L2000
org $1100
L1100 bit L1100
L1103 lda #$11
ldx #$11
L1107 ldy #$11
clv
bvc L1103
org $1100
:L1100_0 bit :L1100_0
lda #$22
:L1105 ldx #$22
ldy #$22
jmp :L1105
org $1100
:L1100_1 bit :L1100_1
lda #$33
ldx #$33
:L1107_0 ldy #$33
sec
bcs :L1107_0
org $2000
L2000 bit L2000
beq $2018
bne :L2020
org $2020
:L2020 bit :L2020
beq $2028
bne L2080
offend nop
org $2080
L2080 bit L2080
lda offend
jsr offend
lda $2028
jsr $2028
lda L2080-1
jsr L2080-1
lda L2080
jsr L2080
lda $00
beq :L2100
dfb $ad
org $2100
:L2100 nop
nop
jmp :L3000
org $2800
dfb $00
dfb $28
ds 14
org $2820
ds 18
org $3000
:L3000 bit :L3000
lda #$44
ldx #$44
ldy #$44
jmp fwd
ulabel dfb $00
dfb $01
org $3100
dfb $02
fwd bit fwd
lda ulabel
lda ulabel+1
lda $300e
lda $300f
lda fwd-1
beq :L3182
dfb $ea
dfb $ea
org $3180
dfb $00
dfb $01
:L3182 bit :L3182
lda label1
lda label1+1
lda L3200
clv
bvc L3200
label1 dfb $ea
dfb $ea
org $3200
L3200 bit L3200
dfb $00
dfb $01 ;execution continues off end of file