6502
/
cc65
mirror of https://github.com/cc65/cc65.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

versionable header for sim65 

load and run address now configured from header
fix error codes not to conflict with test
fix test/misc/endless.c which is supposed to fail if an endless loop does not occur
This commit is contained in:
bbbradsmith 2019-05-29 16:04:54 -04:00 committed by Oliver Schmidt
parent 07ca772932
commit fb7d4acd5c
12 changed files with 129 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
cfg/sim6502.cfg
View File

@ -4,7 +4,7 @@ SYMBOLS {
}
MEMORY {
ZP: file = "", start = $0000, size = $001B;
HEADER: file = %O, start = $0000, size = $0002;
HEADER: file = %O, start = $0000, size = $000C;
MAIN: file = %O, define = yes, start = $0200, size = $FDF0 - __STACKSIZE__;
}
SEGMENTS {

2
cfg/sim65c02.cfg
View File

@ -4,7 +4,7 @@ SYMBOLS {
}
MEMORY {
ZP: file = "", start = $0000, size = $001B;
HEADER: file = %O, start = $0000, size = $0002;
HEADER: file = %O, start = $0000, size = $000C;
MAIN: file = %O, define = yes, start = $0200, size = $FDF0 - __STACKSIZE__;
}
SEGMENTS {

29
doc/sim65.sgml
View File

@ -140,28 +140,39 @@ Assembly tests may similarly be assembled and linked with
and the sim65 library provides an <tt/exit/ symbol that the program may <tt/JMP/
to terminate with the current A register value as an exit code.
Without using the provided target library, there are some relevant internal details:
The binary file has a 12 byte header:
<itemize>
<item>The binary input file has a 2 byte header. The first byte indicates CPU type:
0 = 6502, 1 = 65C02. The second byte is the address of the C parameter stack pointer
<tt/sp/, used by the paravirtualization functions.
<item>5 byte **signature**: <tt/$73, $69, $6D, $36, $35/ or <tt/'sim65'/
<item>The rest of the input file, after the header, will be loaded at <tt/$0200/,
and execution will begin at <tt/$0200/.
<item>1 byte **version**: <tt/2/
<item>1 byte **CPU type**: <tt/0/ = 6502, <tt/1/ = 65C02
<item>1 byte **sp address**: the zero page address of the C parameter stack pointer <tt/sp/ used by the paravirtualization functions
<item>1 word **load address**: where to load the data from the file into memory (default: <tt/$0200/)
<item>1 word **reset address**: specifies where to begin execution after loading (default: <tt/$0200/)
</itemize>
Other internal details:
<itemize>
<item>The entire 64 kilobyte address space is writeable RAM.
Aside from the loaded binary, the reset vector at <tt/$FFFC/ will be
pre-loaded with <tt/$0200/ as the start address.
pre-loaded with the given **reset address**.
<item>The <tt/exit/ address is <tt/$FFF1/.
Jumping to this address will terminate execution with the A register value as an exit code.
<item>The built-in functions are provided by 6 paravirtualization hooks present at
<tt/$FFF0-$FFF5/. Except for <tt/exit/, a <tt/JSR/ to one of these
addresses will return immediately after performing a special function,
intended for use with the sim65 target C library.
addresses will return immediately after performing a special function.
These use cc65 calling conventions, and are intended for use with the sim65 target C library.
<item><tt/IRQ/ and <tt/NMI/ events will not be generated, though <tt/BRK/
can be used if the IRQ vector at <tt/$FFFE/ is manually prepared by the test code.

2
libsrc/sim6502/crt0.s
View File

@ -5,6 +5,7 @@
;
.export _exit
.export sim65start
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import zerobss, callmain
.import initlib, donelib
@ -16,6 +17,7 @@
.segment "STARTUP"
sim65start:
cld
ldx #$FF
txs

10
libsrc/sim6502/exehdr.s
View File

@ -7,8 +7,14 @@
.export __EXEHDR__ : absolute = 1 ; Linker referenced
.importzp sp
.import __MAIN_START__
.import sim65start
.segment "EXEHDR"
.byte .defined(__SIM65C02__)
.byte sp
.byte $73, $69, $6D, $36, $35 ; 'sim65'
.byte 2 ; header version
.byte .defined(__SIM65C02__) ; CPU type
.byte sp ; sp address
.addr __MAIN_START__ ; load address
.addr sim65start ; reset address

18
src/sim65/error.c
View File

@ -69,7 +69,21 @@ void Error (const char* Format, ...)
vfprintf (stderr, Format, ap);
putc ('\n', stderr);
va_end (ap);
exit (EXIT_FAILURE);
exit (SIM65_ERROR);
}
void ErrorCode (int Code, const char* Format, ...)
/* Print an error message and die with the given exit code */
{
va_list ap;
va_start (ap, Format);
fprintf (stderr, "Error: ");
vfprintf (stderr, Format, ap);
putc ('\n', stderr);
va_end (ap);
exit (Code);
}
@ -83,5 +97,5 @@ void Internal (const char* Format, ...)
vfprintf (stderr, Format, ap);
putc ('\n', stderr);
va_end (ap);
exit (EXIT_FAILURE);
exit (SIM65_ERROR);
}

17
src/sim65/error.h
View File

@ -43,6 +43,20 @@
/*****************************************************************************/
/* Data */
/*****************************************************************************/
#define SIM65_ERROR 256
/* Does not use EXIT_FAILURE because it may overlap with test results. */
#define SIM65_ERROR_TIMEOUT 257
/* An error result for max CPU instructions exceeded. */
/*****************************************************************************/
/* Code */
/*****************************************************************************/
@ -55,6 +69,9 @@ void Warning (const char* Format, ...) attribute((format(printf,1,2)));
void Error (const char* Format, ...) attribute((noreturn, format(printf,1,2)));
/* Print an error message and die */
void ErrorCode (int Code, const char* Format, ...) attribute((noreturn, format(printf,2,3)));
/* Print an error message and die with the given exit code */
void Internal (const char* Format, ...) attribute((noreturn, format(printf,1,2)));
/* Print an internal error message and die */

55
src/sim65/main.c
View File

@ -63,6 +63,16 @@ const char* ProgramFile;
/* exit simulator after MaxCycles Cycles */
unsigned long MaxCycles;
/* Header signature 'sim65' */
static const unsigned char HeaderSignature[] = {
0x73, 0x69, 0x6D, 0x36, 0x35
};
#define HEADER_SIGNATURE_LENGTH (sizeof(HeaderSignature)/sizeof(HeaderSignature[0]))
static const unsigned char HeaderVersion = 2;
/*****************************************************************************/
/* Code */
/*****************************************************************************/
@ -135,8 +145,11 @@ static void OptQuitXIns (const char* Opt attribute ((unused)),
static unsigned char ReadProgramFile (void)
/* Load program into memory */
{
int Val;
unsigned Addr = 0x0200;
unsigned I;
int Val, Val2;
int Version;
unsigned Addr;
unsigned Load, Reset;
unsigned char SPAddr = 0x00;
/* Open the file */
@ -145,6 +158,18 @@ static unsigned char ReadProgramFile (void)
Error ("Cannot open '%s': %s", ProgramFile, strerror (errno));
}
/* Verify the header signature */
for (I=0; I<HEADER_SIGNATURE_LENGTH; ++I) {
if ((Val = fgetc(F)) != HeaderSignature[I]) {
Error ("'%s': Invalid header signature.", ProgramFile);
}
}
/* Get header version */
if ((Version = fgetc(F)) != HeaderVersion) {
Error ("'%s': Invalid header version.", ProgramFile);
}
/* Get the CPU type from the file header */
if ((Val = fgetc(F)) != EOF) {
if (Val != CPU_6502 && Val != CPU_65C02) {
@ -158,10 +183,25 @@ static unsigned char ReadProgramFile (void)
SPAddr = Val;
}
/* Get load address */
if (((Val = fgetc(F)) == EOF) ||
((Val2 = fgetc(F)) == EOF)) {
Error ("'%s': Header missing load address", ProgramFile);
}
Load = Val | (Val2 << 8);
/* Get reset address */
if (((Val = fgetc(F)) == EOF) ||
((Val2 = fgetc(F)) == EOF)) {
Error ("'%s': Header missing reset address", ProgramFile);
}
Reset = Val | (Val2 << 8);
/* Read the file body into memory */
Addr = Load;
while ((Val = fgetc(F)) != EOF) {
if (Addr == 0xFF00) {
Error ("'%s': To large to fit into $0200-$FFF0", ProgramFile);
Error ("'%s': To large to fit into $%04X-$FFF0", ProgramFile, Addr);
}
MemWriteByte (Addr++, (unsigned char) Val);
}
@ -174,8 +214,11 @@ static unsigned char ReadProgramFile (void)
/* Close the file */
fclose (F);
Print (stderr, 1, "Loaded '%s' at $0200-$%04X\n", ProgramFile, Addr - 1);
Print (stderr, 1, "Loaded '%s' at $%04X-$%04X\n", ProgramFile, Load, Addr - 1);
Print (stderr, 1, "File version: %d\n", Version);
Print (stderr, 1, "Reset: $%04X\n", Reset);
MemWriteWord(0xFFFC, Reset);
return SPAddr;
}
@ -263,9 +306,7 @@ int main (int argc, char* argv[])
while (1) {
ExecuteInsn ();
if (MaxCycles && (GetCycles () >= MaxCycles)) {
Error ("Maximum number of cycles reached.");
exit (-99); /* do not use EXIT_FAILURE to avoid conflicts with the
same value being used in a test program */
ErrorCode (SIM65_ERROR_TIMEOUT, "Maximum number of cycles reached.");
}
}

17
src/sim65/memory.c
View File

@ -64,6 +64,15 @@ void MemWriteByte (unsigned Addr, unsigned char Val)
void MemWriteWord (unsigned Addr, unsigned Val)
/* Write a word to a memory location */
{
MemWriteByte (Addr, Val & 0xFF);
MemWriteByte (Addr + 1, Val >> 8);
}
unsigned char MemReadByte (unsigned Addr)
/* Read a byte from a memory location */
{
@ -82,7 +91,7 @@ unsigned MemReadWord (unsigned Addr)
unsigned MemReadZPWord (unsigned char Addr)
/* Read a word from the zero page. This function differs from ReadMemW in that
/* Read a word from the zero page. This function differs from MemReadWord in that
** the read will always be in the zero page, even in case of an address
** overflow.
*/
@ -96,10 +105,6 @@ unsigned MemReadZPWord (unsigned char Addr)
void MemInit (void)
/* Initialize the memory subsystem */
{
/* Fill momory with illegal opcode */
/* Fill memory with illegal opcode */
memset (Mem, 0xFF, sizeof (Mem));
/* Set RESET vector to 0x0200 */
Mem[0xFFFC] = 0x00;
Mem[0xFFFD] = 0x02;
}

5
src/sim65/memory.h
View File

@ -47,6 +47,9 @@
void MemWriteByte (unsigned Addr, unsigned char Val);
/* Write a byte to a memory location */
void MemWriteWord (unsigned Addr, unsigned Val);
/* Write a word to a memory location */
unsigned char MemReadByte (unsigned Addr);
/* Read a byte from a memory location */
@ -54,7 +57,7 @@ unsigned MemReadWord (unsigned Addr);
/* Read a word from a memory location */
unsigned MemReadZPWord (unsigned char Addr);
/* Read a word from the zero page. This function differs from ReadMemW in that
/* Read a word from the zero page. This function differs from MemReadWord in that
** the read will always be in the zero page, even in case of an address
** overflow.
*/

9
src/sim65/paravirt.c
View File

@ -103,15 +103,6 @@ static void SetAX (CPURegs* Regs, unsigned Val)
static void MemWriteWord (unsigned Addr, unsigned Val)
{
MemWriteByte (Addr, Val);
Val >>= 8;
MemWriteByte (Addr + 1, Val);
}
static unsigned char Pop (CPURegs* Regs)
{
return MemReadByte (0x0100 + ++Regs->SP);

2
test/misc/endless.c
View File

@ -9,5 +9,5 @@ int main(void)
;
}
printf("error: should not come here\n");
return EXIT_FAILURE;
return EXIT_SUCCESS; /* test verifies failure, not success */
}