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- #include <stdint.h>
- #include <stdio.h>
- #include "../libz80/z80.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 one argument: 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
-
- static Z80Context cpu;
- static uint8_t mem[0x10000];
- // 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 io_read(int unused, uint16_t addr)
- {
- addr &= 0xff;
- if (addr == STDIO_PORT) {
- if (inpt_ptr < inpt_size) {
- return inpt[inpt_ptr++];
- } else {
- return 0;
- }
- } else if (addr == STDIN_SEEK_PORT) {
- 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;
- }
- } else if (addr == FS_DATA_PORT) {
- if (fsdev_ptr < fsdev_size) {
- return fsdev[fsdev_ptr++];
- } else {
- return 0;
- }
- } else if (addr == FS_SEEK_PORT) {
- if (fsdev_seek_tell_cnt != 0) {
- return fsdev_seek_tell_cnt;
- } else if (fsdev_ptr >= fsdev_size) {
- return 1;
- } else {
- return 0;
- }
- } else {
- fprintf(stderr, "Out of bounds I/O read: %d\n", addr);
- return 0;
- }
- }
-
- static void io_write(int unused, uint16_t addr, uint8_t val)
- {
- addr &= 0xff;
- if (addr == STDIO_PORT) {
- // When mem-dumping, we don't output regular stuff.
- #ifndef MEMDUMP
- putchar(val);
- #endif
- } else if (addr == STDIN_SEEK_PORT) {
- 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;
- }
- } else if (addr == FS_DATA_PORT) {
- if (fsdev_ptr < fsdev_size) {
- fsdev[fsdev_ptr++] = val;
- }
- } else if (addr == FS_SEEK_PORT) {
- 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
- }
- } else if (addr == STDERR_PORT) {
- #ifdef VERBOSE
- fputc(val, stderr);
- #endif
- } else {
- fprintf(stderr, "Out of bounds I/O write: %d / %d (0x%x)\n", addr, val, val);
- }
- }
-
- static uint8_t mem_read(int unused, uint16_t addr)
- {
- return mem[addr];
- }
-
- static void mem_write(int unused, uint16_t addr, uint8_t val)
- {
- mem[addr] = val;
- }
-
- int main(int argc, char *argv[])
- {
- if (argc > 2) {
- fprintf(stderr, "Too many args\n");
- return 1;
- }
- // initialize memory
- for (int i=0; i<sizeof(KERNEL); i++) {
- mem[i] = KERNEL[i];
- }
- for (int i=0; i<sizeof(USERSPACE); i++) {
- mem[i+USER_CODE] = USERSPACE[i];
- }
- fsdev_size = 0;
- if (argc == 2) {
- FILE *fp = fopen(argv[1], "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;
- Z80RESET(&cpu);
- cpu.ioRead = io_read;
- cpu.ioWrite = io_write;
- cpu.memRead = mem_read;
- cpu.memWrite = mem_write;
-
- while (!cpu.halted) {
- Z80Execute(&cpu);
- }
- #ifdef MEMDUMP
- for (int i=0; i<0x10000; i++) {
- putchar(mem[i]);
- }
- #endif
- fflush(stdout);
- int res = cpu.R1.br.A;
- if (res != 0) {
- int lineno = cpu.R1.wr.HL;
- int inclineno = 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;
- }
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