Another big change, this time to the NVR. It has been re-done, integrated with the RTC code, and is now ready to be used by other, non-AT-compatible systems, including an ISA card for PC/XT.

2017-10-03 16:26:55 -04:00
parent a1b3c33054
commit 633adc6b02
31 changed files with 1027 additions and 911 deletions
--- a/src/nvr_at.c
+++ b/src/nvr_at.c
@@ -0,0 +1,108 @@
+/*
+ * 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.
+ *
+ *		IBM PC/AT RTC/NVRAM ("CMOS") emulation.
+ *
+ *		The original PC/AT series had DS12885 series modules; later
+ *		versions and clones used the 12886 and/or 1288(C)7 series,
+ *		or the MC146818 series, all with an external battery. Many
+ *		of those batteries would create corrosion issues later on
+ *		in mainboard life...
+ *
+ * Version:	@(#)nvr_at.c	1.0.5	2017/10/02
+ *
+ * Authors:	Miran Grca, <mgrca8@gmail.com>
+ *		Fred N. van Kempen, <decwiz@yahoo.com>
+ *
+ *		Copyright 2016,2017 Miran Grca.
+ *		Copyright 2017 Fred N. van Kempen.
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include "ibm.h"
+#include "cpu/cpu.h"
+#include "io.h"
+#include "device.h"
+#include "machine/machine.h"
+#include "nvr.h"
+
+
+static void
+nvr_write(uint16_t addr, uint8_t val, void *priv)
+{
+    nvr_t *nvr = (nvr_t *)priv;
+
+    if (! (addr & 1)) {
+	nvr->addr = (val & nvr->mask);
+#if 0
+	nvr->nmi_mask = (~val & 0x80);
+#endif
+
+	return;
+    }
+
+    /* Write the chip's registers. */
+    (*nvr->set)(nvr, nvr->addr, val);
+}
+
+
+static uint8_t
+nvr_read(uint16_t addr, void *priv)
+{
+    nvr_t *nvr = (nvr_t *)priv;
+    uint8_t ret;
+
+    if (addr & 1) {
+	/* Read from the chip's registers. */
+	ret = (*nvr->get)(nvr, nvr->addr);
+    } else {
+	ret = nvr->addr;
+    }
+
+    return(ret);
+}
+
+
+void
+nvr_at_close(void *priv)
+{
+    nvr_t *nvr = (nvr_t *)priv;
+
+    if (nvr->fname != NULL)
+	free(nvr->fname);
+
+    free(nvr);
+}
+
+
+void
+nvr_at_init(int irq)
+{
+    nvr_t *nvr;
+
+    /* Allocate an NVR for this machine. */
+    nvr = (nvr_t *)malloc(sizeof(nvr_t));
+    if (nvr == NULL) return;
+    memset(nvr, 0x00, sizeof(nvr_t));
+
+    /* This is machine specific. */
+    nvr->mask = machines[machine].nvrmask;
+    nvr->irq = irq;
+
+    /* Set up any local handlers here. */
+
+    /* Initialize the actual NVR. */
+    nvr_init(nvr);
+
+    /* Set up the PC/AT handler for this device. */
+    io_sethandler(0x0070, 2,
+		  nvr_read, NULL, NULL, nvr_write, NULL, NULL, nvr);
+}