mpw/loader.cpp
2013-02-05 22:46:17 -05:00

386 lines
7.1 KiB
C++

// clang++ -c -std=c++11 -stdlib=libc++ -Wno-deprecated-declarations loader.cpp
#include <cstdint>
#include <cstring>
#include <string>
#include <vector>
#include <sysexits.h>
#include <getopt.h>
#include <CoreServices/CoreServices.h>
uint8_t *memory;
uint32_t HighWater = 2048;
uint32_t EmulatedNewPtr(uint32_t size)
{
if (size & 0x01) size++;
uint32_t address = HighWater;
HighWater += size;
std::memset(memory + HighWater, 0, size);
return address;
}
uint8_t ReadByte(const void *data, uint32_t offset)
{
offset &= 0xffffff;
return ((uint8_t *)data)[offset];
}
uint16_t ReadWord(const void *data, uint32_t offset)
{
offset &= 0xffffff;
return (ReadByte(data, offset) << 8) | ReadByte(data, offset+1);
}
uint32_t ReadLong(const void *data, uint32_t offset)
{
offset &= 0xffffff;
return (ReadWord(data, offset) << 16) | ReadWord(data, offset+2);
}
void WriteByte(void *data, uint32_t offset, uint8_t value)
{
offset &= 0xffffff;
((uint8_t *)data)[offset] = value;
}
void WriteWord(void *data, uint32_t offset, uint16_t value)
{
offset &= 0xffffff;
((uint8_t *)data)[offset++] = value >> 8;
((uint8_t *)data)[offset++] = value;
}
void WriteLong(void *data, uint32_t offset, uint32_t value)
{
offset &= 0xffffff;
((uint8_t *)data)[offset++] = value >> 24;
((uint8_t *)data)[offset++] = value >> 16;
((uint8_t *)data)[offset++] = value >> 8;
((uint8_t *)data)[offset++] = value;
}
/*
//0x0316 = MPWArgs *
struct MPWArgs
{
uint32_t MPGM; // = 'MPGM';
int32_t argptr;
args:
uint16_t SH;
uint32_t argc;
uint32_t argv;
uint32_t envp;
envp stored as key\0value\0, not key=value\0
};
0x910 = name ptr (32-char pstring)
*/
uint32_t load(const char *file)
{
ResFileRefNum refNum;
FSRef ref;
std::vector< std::pair<uint32_t, uint32_t> > segments; // segment, address
memory = new uint8_t[16 * 1024 * 1024];
uint32_t a5 = 0;
uint32_t jtStart = 0;
uint32_t jtEnd = 0;
assert(FSPathMakeRef( (const UInt8 *)file, &ref, NULL) == noErr);
refNum = FSOpenResFile(&ref, fsRdPerm);
assert(refNum != -1 );
int l = Count1Resources('CODE');
segments.reserve(l);
assert(l > 0);
for (int i = 0; i < l; ++i)
{
ResAttributes attr;
ResID resID;
ResType resType;
Str255 name;
char *cname;
uint32_t size;
uint32_t address;
Handle h;
const uint8_t *data;
h = Get1IndResource('CODE', i + 1);
if (!h) continue;
HLock(h);
data = *(const uint8_t **)h;
attr = GetResAttrs(h);
GetResInfo(h, &resID, &resType, name);
size = GetHandleSize(h);
if (segments.size() <= resID) segments.resize(resID + 1);
// can't have duplicate resIDs, so no need to check that...
if (resID == 0)
{
// jump table/a5
uint32_t above = ReadLong(data, 0);
uint32_t below = ReadLong(data, 4);
uint32_t jtSize = ReadLong(data, 8);
uint32_t jtOffset = ReadLong(data, 12);
uint32_t a5size = above + below;
address = EmulatedNewPtr(a5size);
a5 = address + below;
std::memcpy(memory + a5, data, above);
segments[resID] = std::make_pair(address, a5size);
jtStart = a5 + jtOffset;
jtEnd = jtStart + jtSize;
}
else
{
address = EmulatedNewPtr(size);
std::memcpy(memory + address, data, size);
segments[resID] = std::make_pair(address, size);
}
ReleaseResource(h);
}
// now link the segment 0 jump table...
assert(a5);
for (; jtStart < jtEnd; jtStart += 8)
{
uint16_t offset = ReadWord(memory, jtStart);
uint16_t seg = ReadWord(memory, jtStart + 4);
assert(ReadWord(memory, jtStart + 2) == 0x3F3C);
assert(ReadWord(memory, jtStart + 6) == 0xA9F0);
assert(seg < segments.size());
auto p = segments[seg];
assert(p.first); // missing segment?!
assert(offset < p.second);
// +4 for the jump table info header.
uint32_t address = p.first + offset + 4;
// JMP absolute long
WriteWord(memory, jtStart + 2, 0x4EF9);
WriteLong(memory, jtStart + 4, address);
}
// set pc to jump table entry 0.
return a5;
}
void InitializeMPW(int argc, char **argv)
{
// 0x0910 CurApName
{
char str32[32];
int l = strlen(argv[0]);
l = std::min(l, 32);
str32[0] = l;
memcpy(str32 + 1, argv[0], l);
while (l < 32) str32[l++] = 0;
memcpy(memory + 0x910, str32, 32);
}
// 0x0316 is a pointer to the argc, argv, envp.
// very ugly.
uint32_t argvAddress = 0;
uint32_t envpAddress = 0;
{
std::vector<uint32_t> argvSpine;
argvSpine.reserve(argc + 1);
for (int i = 0; i < argc; ++i)
{
int length;
uint32_t address;
length = strlen(argv[i]);
address = EmulatedNewPtr(length + 1);
memcpy(memory + address, argv[i], length + 1);
argvSpine.push_back(address);
}
argvSpine.push_back(0);
argvAddress = EmulatedNewPtr(4 * argvSpine.size());
uint32_t address = argvAddress;
for (uint32_t x : argvSpine)
{
WriteLong(memory, address, x);
address += 4;
}
}
// same thing for envp... but \0 instead of =
uint32_t address = EmulatedNewPtr(8 + 10);
WriteLong(memory, 0x0316, address);
WriteLong(memory, address, 0x4d50474d); // MPGM - magic
WriteLong(memory, address + 4, address + 8); // block ptr
WriteWord(memory, address + 8, 0x5348); // SH - more magic
WriteWord(memory, address + 10, argc);
WriteWord(memory, address + 14, argvAddress);
WriteWord(memory, address + 18, envpAddress);
}
void help()
{
}
bool parse_number(const char *input, uint32_t *dest)
{
char *end;
long value;
int base = 0;
// octal is dumb so don't allow it.
while (isspace(*input)) ++input;
if (*input == '0' && isdigit(input[1])) base = 10;
errno = 0;
value = strtol(input, &end, base);
if (errno || value < 0 || input == end)
{
fprintf(stderr, "%s - invalid input\n", input);
return false;
}
// M/K
if (*end)
{
int old = value;
if (strcasecmp(end, "M") == 0)
value *= 1024 * 1024;
else if (strcasecmp(end, "K") == 0)
value *= 1024;
else
{
fprintf(stderr, "%s - invalid input\n", input);
return false;
}
if (value < old)
{
// overflow
fprintf(stderr, "%s - invalid input\n", input);
return false;
}
}
if (dest) *dest = value;
return true;
}
struct {
uint32_t ram;
uint32_t stack;
uint32_t machine;
} Flags = { 16 * 1024 * 1024, 8 * 1024, 68030 };
int main(int argc, char **argv)
{
// getopt...
static struct option LongOpts[] =
{
{ "ram",required_argument, NULL, 'r' },
{ "stack", required_argument, NULL, 's' },
{ "machine", required_argument, NULL, 'm' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0 }
};
int c;
while ((c = getopt_long(argc, argv, "+hVm:r:s:", LongOpts, NULL)) != -1)
{
switch(c)
{
case 'm':
if (!parse_number(optarg, &Flags.machine))
exit(EX_CONFIG);
break;
case 'r':
if (!parse_number(optarg, &Flags.ram))
exit(EX_CONFIG);
break;
case 's':
if (!parse_number(optarg, &Flags.stack))
exit(EX_CONFIG);
break;
case ':':
case '?':
help();
exit(EX_USAGE);
break;
case 'h':
help();
exit(EX_OK);
break;
case 'V':
printf("mpw version 0");
exit(EX_OK);
break;
}
}
argc -= optind;
argv += optind;
if (!argc)
{
help();
exit(EX_USAGE);
}
load(argv[0]);
InitializeMPW(argc, argv);
}