summaryrefslogtreecommitdiff
path: root/greth.c
diff options
context:
space:
mode:
Diffstat (limited to 'greth.c')
-rw-r--r--greth.c310
1 files changed, 310 insertions, 0 deletions
diff --git a/greth.c b/greth.c
new file mode 100644
index 0000000..9d09087
--- /dev/null
+++ b/greth.c
@@ -0,0 +1,310 @@
+/*
+ * This file is part of SIS.
+ *
+ * SIS, SPARC/RISCV instruction simulator. Copyright (C) 2020 Jiri Gaisler
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+/* Emulation of GRETH 10/100 Mbit network interface */
+/* Based on grlib-gpl-2018.1-b4217/doc/grip.pdf */
+/* Multicast not supported for now ... */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/file.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+
+#include "sis.h"
+
+#define MDIO_WRITE 1
+#define MDIO_READ 2
+#define CTRL_SPEED 0x80
+#define CTRL_RST 0x40
+#define CTRL_RI 8
+#define CTRL_TI 4
+#define CTRL_RE 2
+#define CTRL_TE 1
+#define STATUS_TI 8
+#define STATUS_RI 4
+
+#define BASE_PNT 0x3f8
+#define DESC_EN (1 << 11)
+#define DESC_WRAP (1 << 12)
+#define DESC_IE (1 << 13)
+
+static uint32 greth_ctrl;
+static uint32 greth_status;
+static uint32 greth_macmsb;
+static uint32 greth_maclsb;
+static uint32 greth_mdio;
+static uint32 greth_txbase;
+static uint32 greth_txdesc;
+static uint32 greth_txbuf;
+static unsigned char *greth_txbufptr;
+static uint32 greth_rxbase;
+static uint32 greth_rxdesc;
+static uint32 greth_rxbuf;
+static unsigned char *greth_rxbufptr;
+static unsigned char greth_mac[6];
+static long unsigned mac;
+static const char broadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
+/* Simple emulation of Microchip KSZ8041NL/RNL PHY */
+
+static uint32
+mdio_read (uint32 address)
+{
+ uint32 res;
+
+ switch (address & 0x1F)
+ {
+ case 0:
+ res = 0x3100;
+ break;
+ case 1:
+ res = 0x7865;
+ break;
+ case 2:
+ res = 0x0022;
+ break;
+ case 3:
+ res = 0x1512;
+ break;
+ case 4:
+ res = 0x01ef;
+ break;
+ case 5:
+ res = 0x41e1;
+ break;
+ default:
+ res = 0;
+ }
+
+ if (sis_verbose > 1)
+ printf ("%8lu cpu %d MDIO read a: %02x, d: %04x\n",
+ ebase.simtime, cpu, address, res);
+ return res;
+}
+
+static void
+mdio_write (uint32 address, uint32 data)
+{
+ if (sis_verbose > 1)
+ printf ("%8lu cpu %d MDIO write a: %02x, d: %04x\n",
+ ebase.simtime, cpu, address, data);
+}
+
+static void
+greth_tx (void)
+{
+ int32 ws;
+ uint32 tmpdesc;
+ unsigned char buffer[2048];
+ int len, wlen, i;
+
+ if (greth_ctrl & CTRL_TE)
+ {
+ ms->memory_read (greth_txbase, &greth_txdesc, &ws);
+ if (greth_txdesc & DESC_EN)
+ {
+ ms->memory_read (greth_txbase + 4, &greth_txbuf, &ws);
+ greth_txbufptr = ms->get_mem_ptr (greth_txbuf, 1536);
+ len = greth_txdesc & 0x7ff;
+ /* endian swap on host/target endian mismatch */
+ if (arch->bswap)
+ {
+ wlen = (len + 3) & ~3; // align up to 32-bit word
+ for (i = 0; i < wlen; i++)
+ buffer[i] = greth_txbufptr[arch->bswap ^ i];
+ sis_tap_write ((unsigned char *) buffer, len);
+ }
+ else
+ sis_tap_write (greth_txbufptr, greth_txdesc & 0x7ff);
+ greth_status |= STATUS_TI;
+ if ((greth_ctrl & CTRL_TI) && (greth_txdesc & DESC_IE))
+ ms->set_irq (6);
+ if (sis_verbose)
+ printf ("packet transmitted, len %d, desc %d\n",
+ greth_txdesc & 0x7ff, (greth_txbase & BASE_PNT) >> 3);
+ tmpdesc = greth_txdesc & 0x7ff;
+ ms->memory_write (greth_txbase, &tmpdesc, 2, &ws);
+ if ((greth_txdesc & DESC_WRAP) ||
+ ((greth_txbase & BASE_PNT) == BASE_PNT))
+ greth_txbase &= ~BASE_PNT;
+ else
+ greth_txbase += 8;
+ ms->memory_read (greth_txbase, &greth_txdesc, &ws);
+ }
+ }
+ event (greth_tx, 1, 5000);
+}
+
+/* Write GRETH APB registers */
+
+void
+greth_write (uint32 address, uint32 data)
+{
+ int32 ws;
+
+ switch (address & 0xFC)
+ {
+ case 0:
+ if (data & CTRL_RST)
+ {
+ greth_ctrl = CTRL_SPEED;
+ }
+ else
+ {
+ if ((data & CTRL_RE) && !(greth_ctrl & CTRL_RE) && !mac)
+ {
+ mac = greth_macmsb;
+ mac <<= 32;
+ mac |= greth_maclsb;
+ sis_tap_init (mac);
+ mac = 1;
+ event (greth_tx, 1, 100);
+ sync_rt = 1;
+ }
+ greth_ctrl = data;
+ }
+ break;
+ case 4:
+ greth_status &= ~data;
+ break;
+ case 8:
+ greth_macmsb = data & 0x0ffff;
+ greth_mac[0] = (data >> 8) & 0x0ff;
+ greth_mac[1] = data & 0x0ff;
+ break;
+ case 0x0c:
+ greth_maclsb = data;
+ greth_mac[2] = (data >> 24) & 0x0ff;
+ greth_mac[3] = (data >> 16) & 0x0ff;
+ greth_mac[4] = (data >> 8) & 0x0ff;
+ greth_mac[5] = data & 0x0ff;
+ break;
+ case 0x10:
+ greth_mdio = data & 0xfffffff0;
+ if (data & MDIO_WRITE)
+ {
+ mdio_write ((data >> 6) & 0x1f, data >> 16);
+ }
+ else if (data & MDIO_READ)
+ {
+ greth_mdio = mdio_read ((data >> 6) & 0x1f) << 16;
+ }
+ break;
+ case 0x14:
+ greth_txbase = data & 0xfffffff8;
+ break;
+ case 0x18:
+ greth_rxbase = data & 0xfffffff8;
+ break;
+ }
+ if (sis_verbose > 1)
+ printf ("%8lu cpu %d APB write a: %08x, d: %08x\n",
+ ebase.simtime, cpu, address, data);
+}
+
+/* Read GRETH APB registers */
+
+uint32
+greth_read (uint32 address)
+{
+ uint32 res;
+
+ switch (address & 0xFC)
+ {
+ case 0:
+ res = greth_ctrl;
+ break;
+ case 4:
+ res = greth_status;
+ break;
+ case 8:
+ res = greth_macmsb;
+ break;
+ case 0x0c:
+ res = greth_maclsb;
+ break;
+ case 0x10:
+ res = greth_mdio;
+ break;
+ case 0x14:
+ res = greth_txbase;
+ break;
+ case 0x18:
+ res = greth_rxbase;
+ break;
+ default:
+ res = 0;
+ }
+ if (sis_verbose > 1)
+ printf ("%8lu cpu %d APB read a: %08x, d: %08x\n",
+ ebase.simtime, cpu, address, res);
+ return res;
+}
+
+void
+greth_rxready (unsigned char *buffer, int len)
+{
+ uint32 tmpdesc, ws;
+ int i, wlen;
+
+ if (sis_verbose > 1)
+ {
+ printf ("net: read %d bytes from device\n", len);
+ for (i = 0; i < len; i++)
+ printf ("%02x", buffer[i]);
+ printf ("\n");
+ }
+ /* accept only unicast or broadcast packets */
+ if (((strncmp (greth_mac, buffer, 6) == 0) ||
+ (strncmp (buffer, broadcast, 6) == 0)) && (greth_ctrl & CTRL_RE))
+ {
+ ms->memory_read (greth_rxbase, &greth_rxdesc, &ws);
+ if (greth_rxdesc & DESC_EN)
+ {
+ ms->memory_read (greth_rxbase + 4, &greth_rxbuf, &ws);
+ greth_rxbufptr = ms->get_mem_ptr (greth_rxbuf, 1536);
+ /* endian swap on host/target endian mismatch */
+ if (arch->bswap)
+ {
+ wlen = (len + 3) & ~3; // align up to 32-bit word
+ for (i = 0; i < wlen; i++)
+ greth_rxbufptr[i] = buffer[arch->bswap ^ i];
+ }
+ else
+ memcpy (greth_rxbufptr, buffer, len);
+ tmpdesc = len & 0x7ff;
+ ms->memory_write (greth_rxbase, &tmpdesc, 2, &ws);
+ greth_status |= STATUS_RI;
+ if ((greth_rxdesc & DESC_WRAP)
+ || ((greth_rxbase & BASE_PNT) == BASE_PNT))
+ greth_rxbase &= ~BASE_PNT;
+ else
+ greth_rxbase += 8;
+
+ if ((greth_ctrl & CTRL_RI) && (greth_rxdesc & DESC_IE))
+ ms->set_irq (6);
+ }
+ else if (sis_verbose > 1)
+ printf ("net: received packet dropped!\n");
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-20 16:55:07 +0000