emu_rom_interface.c

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/* Minimalistic Enterprise-128 emulator with focus on "exotic" hardware
   Part of the Xemu project, please visit: https://github.com/lgblgblgb/xemu
   Copyright (C)2015-2016,2020-2021 LGB (Gábor Lénárt) <lgblgblgb@gmail.com>
 
This program 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 2 of the License, or
(at your option) any later version.
 
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
#include "xemu/emutools.h"
#include "xemu/emutools_config.h"
#include "enterprise128.h"
#include "emu_rom_interface.h"
#include "xemu/../rom/ep128/xep_rom_syms.h"
#include "xemu/z80.h"
#include "cpu.h"
#include "roms.h"
#include "emu_monitor.h"
#include "fileio.h"
#include "configdb.h"
 
#include <unistd.h>
#include <time.h>
 
#define XEPSYM_ADDR(sym) (xep_rom_addr + (sym) - 0xC000)
#define XEPSYM_P(sym) (memory + XEPSYM_ADDR(sym))
#define COBUF ((char*)XEPSYM_P(xepsym_cobuf))
#define SET_XEPSYM_BYTE(sym, value) *XEPSYM_P(sym) = (value)
#define SET_XEPSYM_WORD(sym, value) do {        \
        SET_XEPSYM_BYTE(sym, (value) & 0xFF);   \
        SET_XEPSYM_BYTE((sym) + 1, (value) >> 8);       \
} while(0)
#define BIN2BCD(bin) ((((bin) / 10) << 4) | ((bin) % 10))
 
static const char EXOS_NEWLINE[] = "\r\n";
Uint8 exos_version = 0;
Uint8 exos_info[8];
 
#define EXOS_ADDR(n)            (0x3FC000 | ((n) & 0x3FFF))
#define EXOS_BYTE(n)            memory[EXOS_ADDR(n)]
#define EXOS_GET_WORD(n)        (EXOS_BYTE(n) | (EXOS_BYTE((n) + 1) << 8))
 
 
 
void exos_get_status_line ( char *buffer )
{
        Uint8 *s = memory + EXOS_ADDR(EXOS_GET_WORD(0xBFF6));
        int a = 40;
        while (a--)
                *(buffer++) = *(s++) & 0x7F;
        *buffer = '\0';
}
 
 
void xep_set_error ( const char *msg )
{
        int l = strlen(msg);
        if (l > 63)
                l = 63;
        SET_XEPSYM_BYTE(xepsym_error_message_buffer, l);
        memcpy(XEPSYM_P(xepsym_error_message_buffer + 1), msg, l);
        DEBUG("XEP: error msg set len=%d len_stored=%d \"%s\"" NL, l, *XEPSYM_P(xepsym_error_message_buffer), msg);
}
 
 
void xep_set_time_consts ( char *descbuffer )
{
        struct tm *t = localtime(&unix_time);
        SET_XEPSYM_BYTE(xepsym_settime_hour,    BIN2BCD(t->tm_hour));
        SET_XEPSYM_WORD(xepsym_settime_minsec,  (BIN2BCD(t->tm_min) << 8) | BIN2BCD(t->tm_sec));
        SET_XEPSYM_BYTE(xepsym_setdate_year,    BIN2BCD(t->tm_year - 80));
        SET_XEPSYM_WORD(xepsym_setdate_monday,  (BIN2BCD(t->tm_mon + 1) << 8) | BIN2BCD(t->tm_mday));
        if (descbuffer)
                sprintf(descbuffer, "%04d-%02d-%02d %02d:%02d:%02d",
                        t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
                        t->tm_hour, t->tm_min, t->tm_sec
                );
        SET_XEPSYM_WORD(xepsym_jump_on_rom_entry, xepsym_set_time);
}
 
 
 
/* Sets XEP ROM jump to the code fragment to utilize EXOS 19 call
   to set default device name provided, with also storing the given
   name */
void xep_set_default_device_name ( const char *name )
{
        int l;
        if (!name)
                name = configdb.ddn;
        if (!name)
                name = "";
        l = strlen(name);
        if (l < 16) {
                if (l)
                        memcpy(XEPSYM_P(xepsym_default_device_name_string + 1), name, l);
                SET_XEPSYM_BYTE(xepsym_default_device_name_string, l);
                SET_XEPSYM_WORD(xepsym_jump_on_rom_entry, xepsym_set_default_device_name);
                SET_XEPSYM_BYTE(xepsym_set_default_device_name_is_file_handler, strncasecmp(name, "TAPE", 4) ? 1 : 0);
        } else
                ERROR_WINDOW("Too long default device name is tried to be set, ignoring!");
}
 
 
 
static int exos_cmd_name_match ( const char *that, Uint16 addr )
{
        if (strlen(that) != Z80_B) return 0;
        while (*that)
                if (*(that++) != read_cpu_byte(addr++))
                        return 0;
        return 1;
}
 
 
 
static void xep_exos_command_trap ( void )
{
        Uint8 c = Z80_C, b = Z80_B;
        Uint16 de = Z80_DE;
        int size;
        *COBUF = 0; // no ans by def
        DEBUG("XEP: COMMAND TRAP: C=%02Xh, B=%02Xh, DE=%04Xh" NL, c, b, de);
        /* restore exos command handler jump address */
        SET_XEPSYM_WORD(xepsym_jump_on_rom_entry, xepsym_print_xep_buffer);
        switch (c) {
                case 2: // EXOS command
                        if (exos_cmd_name_match("XEP", de + 1)) {
                                char buffer[256];
                                char *p = buffer;
                                b = read_cpu_byte(de) - 3;
                                de += 4;
                                while (b--)
                                        *(p++) = read_cpu_byte(de++);
                                *p = '\0';
                                monitor_execute(
                                        buffer,                 // input buffer
                                        1,                      // source system (XEP ROM)
                                        COBUF,                  // output buffer (directly into the co-buffer area!)
                                        xepsym_cobuf_size - 1,  // max allowed output size
                                        EXOS_NEWLINE            // newline delimiter requested (for EXOS we use this fixed value! unlike with console/monitor where it's host-OS dependent!)
                                );
                                Z80_A = 0;
                                Z80_C = 0;
                        }
                        break;
                case 3: // EXOS help
                        if (!b) {
                                // eg on :HELP (ROM list) we patch the request as ROMNAME monitor command ...
                                monitor_execute("ROMNAME", 1, COBUF, xepsym_cobuf_size - 1, EXOS_NEWLINE);
                                Z80_A = 0;
                        } else if (exos_cmd_name_match("XEP", de + 1)) {
                                monitor_execute("HELP", 1, COBUF, xepsym_cobuf_size - 1, EXOS_NEWLINE);
                                Z80_A = 0;
                                Z80_C = 0;
                        }
                        break;
                case 8: // Initialization
                        // Tell XEP ROM to set EXOS date/time with setting we will provide here
                        xep_set_time_consts(NULL);
                        SET_XEPSYM_WORD(xepsym_jump_on_rom_entry, xepsym_system_init);
                        break;
                case 1: // Cold reset (app program can take control here) after the copyright msg ...
                        SET_XEPSYM_WORD(xepsym_jump_on_rom_entry, xepsym_cold_reset);
                        break;
                case 5: // explain error code ...
                        DEBUG("XEP: explain error code of %02Xh our=%d" NL, Z80_B, Z80_B == XEP_ERROR_CODE);
                        if (Z80_B == XEP_ERROR_CODE) {
                                Z80_B = xep_rom_seg;
                                Z80_DE = xepsym_error_message_buffer;
                                Z80_C = 0; // signal that we recognized the error code
                        }
                        break;
        }
        size = strlen(COBUF);
        if (size)
                DEBUG("XEP: ANSWER: [%d bytes] = \"%s\"" NL, size, COBUF);
        // just a sanity check, monitor_execute() would not allow - in theory ... - to store more data than specified (by MPRINTF)
        if (size > xepsym_cobuf_size - 1)
                FATAL("FATAL: XEP ROM answer is too large, %d bytes.", size);
        SET_XEPSYM_WORD(xepsym_print_size, size);       // set print-out size (0 = no print)
}
 
 
 
void xep_rom_trap ( Uint16 pc, Uint8 opcode )
{
        xep_rom_write_support(0);       // to be safe, let's switch writable XEP ROM off (maybe it was enabled by previous trap?)
        DEBUG("XEP: ROM trap at PC=%04Xh OPC=%02Xh" NL, pc, opcode);
        if (opcode != xepsym_ed_trap_opcode)
                FATAL("FATAL: Unknown ED-trap opcode in XEP ROM: PC=%04Xh ED_OP=%02Xh", pc, opcode);
        switch (pc) {
                case xepsym_trap_enable_rom_write:
                        DEBUG("XEP: write access to XEP ROM was requested" NL);
                        xep_rom_write_support(1);       // special ROM request to enable ROM write ... Danger Will Robinson!!
                        break;
                case xepsym_trap_exos_command:
                        xep_exos_command_trap();
                        break;
                case xepsym_trap_on_system_init:
                        exos_version = Z80_B;   // store EXOS version number we got ...
                        memcpy(exos_info, memory + ((xepsym_exos_info_struct & 0x3FFF) | (xep_rom_seg << 14)), 8);
                        if (configdb.skiplogo) {
                                DEBUG("XEP: skiplogo option requested logo skip, etting EXOS variable 0xBFEF to 1 on system init ROM call" NL);
                                EXOS_BYTE(0xBFEF) = 1; // use this, to skip Enterprise logo when it arrives :-)
                        }
                        break;
                default:
                        FATAL("FATAL: Unknown ED-trap location in XEP ROM: PC=%04Xh (ED_OP=%02Xh)", pc, opcode);
                        break;
                //
                /* ---- FILEIO RELATED TRAPS ---- */
                //
                case xepsym_trap_set_default_device_name_feedback:
                        // TODO: handle this :)
                        break;
                case xepsym_fileio_open_channel_remember:
                        fileio_func_open_channel_remember();
                        break;
                case xepsym_fileio_no_used_call:
                        fileio_func_not_used_call();
                        break;
                case xepsym_fileio_open_channel:
                        fileio_func_open_or_create_channel(0);
                        break;
                case xepsym_fileio_create_channel:
                        fileio_func_open_or_create_channel(1);
                        break;
                case xepsym_fileio_close_channel:
                        fileio_func_close_channel();
                        break;
                case xepsym_fileio_destroy_channel:
                        fileio_func_destroy_channel();
                        break;
                case xepsym_fileio_read_character:
                        fileio_func_read_character();
                        break;
                case xepsym_fileio_read_block:
                        fileio_func_read_block();
                        break;
                case xepsym_fileio_write_character:
                        fileio_func_write_character();
                        break;
                case xepsym_fileio_write_block:
                        fileio_func_write_block();
                        break;
                case xepsym_fileio_channel_read_status:
                        fileio_func_channel_read_status();
                        break;
                case xepsym_fileio_set_channel_status:
                        fileio_func_set_channel_status();
                        break;
                case xepsym_fileio_special_function:
                        fileio_func_special_function();
                        break;
                case xepsym_fileio_init:
                        fileio_func_init();
                        break;
                case xepsym_fileio_buffer_moved:
                        fileio_func_buffer_moved();
                        break;
        }
}