Added IBM PCjr cartridge support.

src/device/CMakeLists.txt

@@ -13,7 +13,7 @@
 #		Copyright 2020,2021 David Hrdlička.
 #
 
-add_library(dev OBJECT bugger.c cassette.c hasp.c hwm.c hwm_lm75.c hwm_lm78.c hwm_gl518sm.c
+add_library(dev OBJECT bugger.c cassette.c cartridge.c hasp.c hwm.c hwm_lm75.c hwm_lm78.c hwm_gl518sm.c
 	hwm_vt82c686.c ibm_5161.c isamem.c isartc.c ../lpt.c pci_bridge.c
 	postcard.c serial.c vpc2007.c clock_ics9xxx.c isapnp.c i2c.c i2c_gpio.c
 	smbus_piix4.c keyboard.c keyboard_xt.c keyboard_at.c mouse.c mouse_bus.c

src/device/cartridge.c

@@ -0,0 +1,208 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box distribution.
+ *
+ *		Implementation of the PCjr cartridge emulation.
+ *
+ *
+ *
+ * Authors:	Miran Grca, <mgrca8@gmail.com>
+ *
+ *		Copyright 2021 Miran Grca.
+ */
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+#define HAVE_STDARG_H
+#include <86box/86box.h>
+#include <86box/timer.h>
+#include <86box/plat.h>
+#include <86box/ui.h>
+#include <86box/mem.h>
+#include <86box/machine.h>
+#include <86box/cartridge.h>
+
+
+typedef struct
+{
+    uint8_t *	buf;
+    uint32_t	base;
+} cart_t;
+
+
+char		cart_fns[2][512];
+
+
+static cart_t		carts[2];
+
+static mem_mapping_t	cart_mappings[2];
+
+
+#ifdef ENABLE_CARTRIDGE_LOG
+int cartridge_do_log = ENABLE_CARTRIDGE_LOG;
+
+
+static void
+cartridge_log(const char *fmt, ...)
+{
+   va_list ap;
+
+   if (cartridge_do_log)
+   {
+	va_start(ap, fmt);
+	pclog_ex(fmt, ap);
+	va_end(ap);
+   }
+}
+#else
+#define cartridge_log(fmt, ...)
+#endif
+
+
+static uint8_t
+cart_read(uint32_t addr, void *priv)
+{
+    cart_t *dev = (cart_t *) priv;
+
+    return dev->buf[addr - dev->base];
+}
+
+
+static void
+cart_load_error(int drive, char *fn)
+{
+    cartridge_log("Cartridge: could not load '%s'\n",fn);
+    memset(cart_fns[drive], 0, sizeof(cart_fns[drive]));
+    ui_sb_update_icon_state(SB_CARTRIDGE | drive, 1);
+}
+
+
+static void
+cart_image_close(int drive)
+{
+    if (carts[drive].buf != NULL) {
+	free(carts[drive].buf);
+	carts[drive].buf = NULL;
+    }
+
+    carts[drive].base = 0x00000000;
+
+    mem_mapping_disable(&cart_mappings[drive]);
+}
+
+
+static void
+cart_image_load(int drive, char *fn)
+{
+    FILE *f;
+    uint32_t size;
+    uint32_t base = 0x00000000;
+
+    cart_image_close(drive);
+
+    f = fopen(fn, "rb");
+    if (fseek(f, 0, SEEK_END) == -1)
+	fatal("cart_image_load(): Error seeking to the end of the file\n");
+    size = ftell(f);
+    if (size < 0x1200) {
+	cartridge_log("cart_image_load(): File size %i is too small\n", size);
+	cart_load_error(drive, fn);
+	return;
+    }
+    if (size & 0x00000fff) {
+	size -= 0x00000200;
+	fseek(f, 0x000001ce, SEEK_SET);
+	fread(&base, 1, 2, f);
+	base <<= 4;
+	fseek(f, 0x00000200, SEEK_SET);
+	carts[drive].buf = (uint8_t *) malloc(size);
+	memset(carts[drive].buf, 0x00, size);
+	fread(carts[drive].buf, 1, size, f);
+	fclose(f);
+    } else {
+	base = drive ? 0xe0000 : 0xd0000;
+	fseek(f, 0x00000000, SEEK_SET);
+	carts[drive].buf = (uint8_t *) malloc(size);
+	memset(carts[drive].buf, 0x00, size);
+	fread(carts[drive].buf, 1, size, f);
+	fclose(f);
+    }
+
+    cartridge_log("cart_image_load(): %s at %08X-%08X\n", fn, base, base + size - 1);
+    carts[drive].base = base;
+    mem_mapping_set_addr(&cart_mappings[drive], base, size);
+    mem_mapping_set_exec(&cart_mappings[drive], carts[drive].buf);
+    mem_mapping_set_p(&cart_mappings[drive], &(carts[drive]));
+}
+
+
+static void
+cart_load_common(int drive, char *fn, uint8_t hard_reset)
+{
+    FILE *f;
+
+    cartridge_log("Cartridge: loading drive %d with '%s'\n", drive, fn);
+
+    if (!fn)
+	return;
+    f = plat_fopen(fn, "rb");
+    if (f) {
+	fclose(f);
+	strcpy(cart_fns[drive], fn);
+	cart_image_load(drive, cart_fns[drive]);
+	/* On the real PCjr, inserting a cartridge causes a reset
+	   in order to boot from the cartridge. */
+	if (!hard_reset)
+		resetx86();
+    } else
+	cart_load_error(drive, fn);
+}
+
+
+void
+cart_load(int drive, char *fn)
+{
+    cart_load_common(drive, fn, 0);
+}
+
+
+void
+cart_close(int drive)
+{
+    cartridge_log("Cartridge: closing drive %d\n", drive);
+
+    cart_image_close(drive);
+    cart_fns[drive][0] = 0;
+    ui_sb_update_icon_state(SB_CARTRIDGE | drive, 1);
+}
+
+
+void
+cart_reset(void)
+{
+    int i;
+
+    cart_image_close(1);
+    cart_image_close(0);
+
+    if (!(machines[machine].flags & MACHINE_CARTRIDGE))
+	return;
+
+    for (i = 0; i < 2; i++) {
+	mem_mapping_add(&cart_mappings[i], 0x000d0000, 0x00002000,
+			cart_read,NULL,NULL,
+			NULL,NULL,NULL,
+			NULL, MEM_MAPPING_EXTERNAL, NULL);
+	mem_mapping_disable(&cart_mappings[i]);
+    }
+
+    cart_load_common(0, cart_fns[0], 1);
+    cart_load_common(1, cart_fns[1], 1);
+}