collapseos/tools/emul/zasm/zasm.c
2019-12-02 17:28:01 -05:00

246 lines
5.8 KiB
C

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "../emul.h"
#include "kernel-bin.h"
#include "zasm-bin.h"
/* zasm reads from a specified blkdev, assemble the file and writes the result
* in another specified blkdev. In our emulator layer, we use stdin and stdout
* as those specified blkdevs.
*
* This executable takes two arguments. Both are optional, but you need to
* specify the first one if you want to get to the second one.
* The first one is the value to send to z80-zasm's 3rd argument (the initial
* .org). Defaults to '00'.
* The second one is the path to a .cfs file to use for includes.
*
* Because the input blkdev needs support for Seek, we buffer it in the emulator
* layer.
*
* Memory layout:
*
* 0x0000 - 0x3fff: ROM code from zasm_glue.asm
* 0x4000 - 0x47ff: RAM for kernel and stack
* 0x4800 - 0x57ff: Userspace code
* 0x5800 - 0xffff: Userspace RAM
*
* I/O Ports:
*
* 0 - stdin / stdout
* 1 - When written to, rewind stdin buffer to the beginning.
*/
// in sync with zasm_glue.asm
#define USER_CODE 0x4800
#define STDIO_PORT 0x00
#define STDIN_SEEK_PORT 0x01
#define FS_DATA_PORT 0x02
#define FS_SEEK_PORT 0x03
#define STDERR_PORT 0x04
// Other consts
#define STDIN_BUFSIZE 0x8000
// When defined, we dump memory instead of dumping expected stdout
//#define MEMDUMP
//#define DEBUG
// By default, we don't spit what zasm prints. Too noisy. Define VERBOSE if
// you want to spit this content to stderr.
//#define VERBOSE
// STDIN buffer, allows us to seek and tell
static uint8_t inpt[STDIN_BUFSIZE];
static int inpt_size;
static int inpt_ptr;
static uint8_t middle_of_seek_tell = 0;
static uint8_t fsdev[0x40000] = {0};
static uint32_t fsdev_size = 0;
static uint32_t fsdev_ptr = 0;
static uint8_t fsdev_seek_tell_cnt = 0;
static uint8_t iord_stdio()
{
if (inpt_ptr < inpt_size) {
return inpt[inpt_ptr++];
} else {
return 0;
}
}
static uint8_t iord_stdin_seek()
{
if (middle_of_seek_tell) {
middle_of_seek_tell = 0;
return inpt_ptr & 0xff;
} else {
#ifdef DEBUG
fprintf(stderr, "tell %d\n", inpt_ptr);
#endif
middle_of_seek_tell = 1;
return inpt_ptr >> 8;
}
}
static uint8_t iord_fsdata()
{
if (fsdev_ptr < fsdev_size) {
return fsdev[fsdev_ptr++];
} else {
return 0;
}
}
static uint8_t iord_fsseek()
{
if (fsdev_seek_tell_cnt != 0) {
return fsdev_seek_tell_cnt;
} else if (fsdev_ptr >= fsdev_size) {
return 1;
} else {
return 0;
}
}
static void iowr_stdio(uint8_t val)
{
// When mem-dumping, we don't output regular stuff.
#ifndef MEMDUMP
putchar(val);
#endif
}
static void iowr_stdin_seek(uint8_t val)
{
if (middle_of_seek_tell) {
inpt_ptr |= val;
middle_of_seek_tell = 0;
#ifdef DEBUG
fprintf(stderr, "seek %d\n", inpt_ptr);
#endif
} else {
inpt_ptr = (val << 8) & 0xff00;
middle_of_seek_tell = 1;
}
}
static void iowr_fsdata(uint8_t val)
{
if (fsdev_ptr < fsdev_size) {
fsdev[fsdev_ptr++] = val;
}
}
static void iowr_fsseek(uint8_t val)
{
if (fsdev_seek_tell_cnt == 0) {
fsdev_ptr = val << 16;
fsdev_seek_tell_cnt = 1;
} else if (fsdev_seek_tell_cnt == 1) {
fsdev_ptr |= val << 8;
fsdev_seek_tell_cnt = 2;
} else {
fsdev_ptr |= val;
fsdev_seek_tell_cnt = 0;
#ifdef DEBUG
fprintf(stderr, "FS seek %d\n", fsdev_ptr);
#endif
}
}
static void iowr_stderr(uint8_t val)
{
#ifdef VERBOSE
fputc(val, stderr);
#endif
}
int main(int argc, char *argv[])
{
if (argc > 3) {
fprintf(stderr, "Too many args\n");
return 1;
}
Machine *m = emul_init();
m->iord[STDIO_PORT] = iord_stdio;
m->iord[STDIN_SEEK_PORT] = iord_stdin_seek;
m->iord[FS_DATA_PORT] = iord_fsdata;
m->iord[FS_SEEK_PORT] = iord_fsseek;
m->iowr[STDIO_PORT] = iowr_stdio;
m->iowr[STDIN_SEEK_PORT] = iowr_stdin_seek;
m->iowr[FS_DATA_PORT] = iowr_fsdata;
m->iowr[FS_SEEK_PORT] = iowr_fsseek;
m->iowr[STDERR_PORT] = iowr_stderr;
// initialize memory
for (int i=0; i<sizeof(KERNEL); i++) {
m->mem[i] = KERNEL[i];
}
for (int i=0; i<sizeof(USERSPACE); i++) {
m->mem[i+USER_CODE] = USERSPACE[i];
}
char *init_org = "00";
if (argc >= 2) {
init_org = argv[1];
if (strlen(init_org) != 2) {
fprintf(stderr, "Initial org must be a two-character hex string");
}
}
// glue.asm knows that it needs to fetch these arguments at this address.
m->mem[0xff00] = init_org[0];
m->mem[0xff01] = init_org[1];
fsdev_size = 0;
if (argc == 3) {
FILE *fp = fopen(argv[2], "r");
if (fp == NULL) {
fprintf(stderr, "Can't open file %s\n", argv[1]);
return 1;
}
int c = fgetc(fp);
while (c != EOF) {
fsdev[fsdev_size] = c;
fsdev_size++;
c = fgetc(fp);
}
fclose(fp);
}
// read stdin in buffer
inpt_size = 0;
inpt_ptr = 0;
int c = getchar();
while (c != EOF) {
inpt[inpt_ptr] = c & 0xff;
inpt_ptr++;
if (inpt_ptr == STDIN_BUFSIZE) {
break;
}
c = getchar();
}
inpt_size = inpt_ptr;
inpt_ptr = 0;
emul_loop();
#ifdef MEMDUMP
for (int i=0; i<0x10000; i++) {
putchar(mem[i]);
}
#endif
fflush(stdout);
int res = m->cpu.R1.br.A;
if (res != 0) {
int lineno = m->cpu.R1.wr.HL;
int inclineno = m->cpu.R1.wr.DE;
if (inclineno) {
fprintf(
stderr,
"Error %d on line %d, include line %d\n",
res,
lineno,
inclineno);
} else {
fprintf(stderr, "Error %d on line %d\n", res, lineno);
}
}
return res;
}