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[SIM65] Support undocumented opcodes for 6502

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This PR is mostly a complete rewrite of the emulator for 6502/65c02 opcodes.
It provides an easier to maintain implementation of the instructions, by using few macros rather than having hand-written code for each function.
All undocumented, previously missing opcodes for 6502 are also implemented.
The patch also includes a detailed documentation of those opcodes, for reference to developers.
This PR should fix one of the milestones listed here for the next version of CC65:

https://github.com/cc65/wiki/wiki/Before-the-next-release
This commit is contained in:
Carlo Bramini 2024-01-04 13:12:52 +01:00 committed by Carlo Bramini
parent 75461e1319
commit b04d79b1da
5 changed files with 1805 additions and 925 deletions
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2
asminc/cpu.mac
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@ -15,7 +15,7 @@ CPU_ISET_4510 = $0400
CPU_NONE = CPU_ISET_NONE
CPU_6502 = CPU_ISET_6502
CPU_6502X = CPU_ISET_6502|CPU_ISET_6502X
CPU_6502DTV = CPU_ISET_6502|CPU_ISET_6502X|CPU_ISET_6502DTV
CPU_6502DTV = CPU_ISET_6502|CPU_ISET_6502DTV
CPU_65SC02 = CPU_ISET_6502|CPU_ISET_65SC02
CPU_65C02 = CPU_ISET_6502|CPU_ISET_65SC02|CPU_ISET_65C02
CPU_65816 = CPU_ISET_6502|CPU_ISET_65SC02|CPU_ISET_65816

12
libsrc/sim6502/exehdr.s
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@ -9,11 +9,21 @@
.import __MAIN_START__
.import startup
.macpack cpu
.segment "EXEHDR"
.byte $73, $69, $6D, $36, $35 ; 'sim65'
.byte 2 ; header version
.byte .defined(__SIM65C02__) ; CPU type
.if (.cpu .bitand ::CPU_ISET_6502X)
.byte 2
.elseif (.cpu .bitand ::CPU_ISET_65C02)
.byte 1
.elseif (.cpu .bitand ::CPU_ISET_6502)
.byte 0
.else
.error Unknow CPU type.
.endif
.byte sp ; sp address
.addr __MAIN_START__ ; load address
.addr startup ; reset address

2703
src/sim65/6502.c
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File diff suppressed because it is too large Load Diff

3
src/sim65/6502.h
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@ -47,7 +47,8 @@
/* Supported CPUs */
typedef enum CPUType {
CPU_6502,
CPU_65C02
CPU_65C02,
CPU_6502X
} CPUType;
/* Current CPU */

10
src/sim65/main.c
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@ -177,10 +177,16 @@ static unsigned char ReadProgramFile (void)
/* Get the CPU type from the file header */
if ((Val = fgetc(F)) != EOF) {
if (Val != CPU_6502 && Val != CPU_65C02) {
switch (Val) {
case CPU_6502:
case CPU_65C02:
case CPU_6502X:
CPU = Val;
break;
default:
Error ("'%s': Invalid CPU type", ProgramFile);
}
CPU = Val;
}
/* Get the address of sp from the file header */