Add mock CharMon (character-based monitor) peripheral.

This fake peripheral can be used to print to the emulator's stdout from
the emulated software.

Author: giomba

CMakeLists.txt

@@ -18,6 +18,7 @@ set(CORE_SRCS
     src/int.c
     src/keyboard.c
     src/main.c
+    src/charmon.c
     src/serial.c
     src/sio2.c
     src/speaker.c

src/charmon.c

@@ -0,0 +1,26 @@
+#include "charmon.h"
+
+#include "conf.h"
+#include "ubus.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#define CHARMON_BASE (0xF0)
+
+void charmon_out(ceda_ioaddr_t address, uint8_t value) {
+    (void)address;
+    (void)putc(value, stdout);
+}
+
+void charmon_init(CEDAModule *mod) {
+    memset(mod, 0, sizeof(*mod));
+
+    bool *conf_installed = conf_getBool("mod", "charmon_installed");
+    bool installed = conf_installed ? *conf_installed : false;
+
+    if (!installed)
+        return;
+
+    ubus_register(CHARMON_BASE, CHARMON_BASE + 1, NULL, charmon_out);
+}

src/charmon.h

@@ -0,0 +1,10 @@
+#ifndef CEDA_CHAR_MONITOR_H
+#define CEDA_CHAR_MONITOR_H
+
+#include "module.h"
+#include "type.h"
+
+void charmon_init(CEDAModule *mod);
+void charmon_out(ceda_ioaddr_t address, uint8_t value);
+
+#endif // CEDA_CHAR_MONITOR_H

src/conf.c

@@ -23,6 +23,7 @@ static const char *CONF_PATH_HOME =
 // Emulator dynamic configuration
 static struct {
     bool cge_installed;
+    bool charmon_installed;
     ceda_string_t *bios_rom_path;
     ceda_string_t *char_rom_path;
     ceda_string_t *cge_rom_path;
@@ -46,6 +47,7 @@ typedef struct conf_tuple_t {
 
 static conf_tuple_t conf_tuples[] = {
     {"mod", "cge_installed", CONF_BOOL, &conf.cge_installed},
+    {"mod", "charmon_installed", CONF_BOOL, &conf.charmon_installed},
     {"path", "bios_rom", CONF_STR, &conf.bios_rom_path},
     {"path", "char_rom", CONF_STR, &conf.char_rom_path},
     {"path", "cge_rom", CONF_STR, &conf.cge_rom_path},