A set of minimal dependency bootstrap binaries
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stage0/vm.c

156 lines
3.4 KiB

/* Copyright (C) 2016 Jeremiah Orians
* This file is part of stage0.
*
* stage0 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* stage0 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with stage0. If not, see <http://www.gnu.org/licenses/>.
*/
#include "vm.h"
#include <getopt.h>
/* Load program tape into Memory */
size_t load_program(struct lilith* vm, char* rom_name)
{
FILE* program;
program = fopen(rom_name, "r");
/* Figure out how much we need to load */
fseek(program, 0, SEEK_END);
size_t end = ftell(program);
rewind(program);
/* Deal with the special case of the ROM is bigger than available memory */
if(end > vm->amount_of_Ram)
{
fprintf(stderr, "Program %s is %d bytes large but only %d bytes of memory have been allocated!\n", rom_name, (int)end, (int)vm->amount_of_Ram);
exit(EXIT_FAILURE);
}
/* Load the entire tape into memory */
fread(vm->memory, 1, end, program);
fclose(program);
return end;
}
void execute_vm(struct lilith* vm)
{
struct Instruction* current;
current = calloc(1, sizeof(struct Instruction));
while(!vm->halted)
{
read_instruction(vm, current);
eval_instruction(vm, current);
}
free(current);
return;
}
/* Standard C main program */
int main(int argc, char **argv)
{
POSIX_MODE = false;
int c;
int Memory_Size = (16 * 1024);
tape_01_name = "tape_01";
tape_02_name = "tape_02";
char* rom_name = NULL;
char class;
static struct option long_options[] = {
{"rom", required_argument, 0, 'r'},
{"tape_01", required_argument, 0, '1'},
{"tape_02", required_argument, 0, '2'},
{"memory", required_argument, 0, 'm'},
{"POSIX-MODE", no_argument, 0, 'P'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
int option_index = 0;
while ((c = getopt_long(argc, argv, "r:h:1:2:m:P", long_options, &option_index)) != -1)
{
switch (c)
{
case 0: break;
case 'r':
{
rom_name = optarg;
break;
}
case 'h':
{
fprintf(stdout, "Usage: %s --rom $rom [--tape_01 $foo] [--tape_02 $bar]\n", argv[0]);
exit(EXIT_SUCCESS);
}
case '1':
{
tape_01_name = optarg;
break;
}
case '2':
{
tape_02_name = optarg;
break;
}
case 'm':
{
int length = strlen(optarg) - 1;
class = optarg[length];
optarg[length] = 0;
Memory_Size = atoi(optarg);
if('K' == class)
{
Memory_Size = Memory_Size * 1024;
}
else if('M' == class)
{
Memory_Size = Memory_Size * 1024 * 1024;
}
else if('G' == class)
{
Memory_Size = Memory_Size * 1024 * 1024 * 1024;
}
break;
}
case 'P':
{
POSIX_MODE = true;
break;
}
default:
{
exit(EXIT_FAILURE);
}
}
}
if(NULL == rom_name)
{
fprintf(stderr, "Usage: %s --rom $rom [--tape_01 $foo] [--tape_02 $bar]\n", argv[0]);
exit(EXIT_FAILURE);
}
/* Perform all the essential stages in order */
struct lilith* vm;
size_t image;
vm = create_vm(Memory_Size);
image = load_program(vm, rom_name);
if(POSIX_MODE) vm->reg[15] = image;
execute_vm(vm);
destroy_vm(vm);
return EXIT_SUCCESS;
}