eepro100: Don't allow writing SCBStatus

SCBStatus is readonly, but most drivers which were derived
from the old Linux eepro100.c do a word write to this address
when they want to acknowledge interrupts.

So we have to mask these writes here.

The patch also removes old unused code for status read / write.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/eepro100.c

@@ -237,10 +237,6 @@ typedef struct {
     /* Statistical counters. Also used for wake-up packet (i82559). */
     eepro100_stats_t statistics;
 
-#if 0
-    uint16_t status;
-#endif
-
     /* Configuration bytes. */
     uint8_t configuration[22];
 
@@ -693,21 +689,6 @@ static char *regname(uint32_t addr)
 }
 #endif                          /* DEBUG_EEPRO100 */
 
-#if 0
-static uint16_t eepro100_read_status(EEPRO100State * s)
-{
-    uint16_t val = s->status;
-    TRACE(OTHER, logout("val=0x%04x\n", val));
-    return val;
-}
-
-static void eepro100_write_status(EEPRO100State * s, uint16_t val)
-{
-    TRACE(OTHER, logout("val=0x%04x\n", val));
-    s->status = val;
-}
-#endif
-
 /*****************************************************************************
  *
  * Command emulation.
@@ -1364,15 +1345,7 @@ static uint8_t eepro100_read1(EEPRO100State * s, uint32_t addr)
 
     switch (addr) {
     case SCBStatus:
-#if 0
-        val = eepro100_read_status(s);
-#endif
-        TRACE(OTHER, logout("addr=%s val=0x%02x\n", regname(addr), val));
-        break;
     case SCBAck:
-#if 0
-        val = eepro100_read_status(s);
-#endif
         TRACE(OTHER, logout("addr=%s val=0x%02x\n", regname(addr), val));
         break;
     case SCBCmd:
@@ -1415,9 +1388,6 @@ static uint16_t eepro100_read2(EEPRO100State * s, uint32_t addr)
 
     switch (addr) {
     case SCBStatus:
-#if 0
-        val = eepro100_read_status(s);
-#endif
     case SCBCmd:
         TRACE(OTHER, logout("addr=%s val=0x%04x\n", regname(addr), val));
         break;
@@ -1441,9 +1411,6 @@ static uint32_t eepro100_read4(EEPRO100State * s, uint32_t addr)
 
     switch (addr) {
     case SCBStatus:
-#if 0
-        val = eepro100_read_status(s);
-#endif
         TRACE(OTHER, logout("addr=%s val=0x%08x\n", regname(addr), val));
         break;
     case SCBPointer:
@@ -1468,7 +1435,8 @@ static uint32_t eepro100_read4(EEPRO100State * s, uint32_t addr)
 
 static void eepro100_write1(EEPRO100State * s, uint32_t addr, uint8_t val)
 {
-    if (addr <= sizeof(s->mem) - sizeof(val)) {
+    /* SCBStatus is readonly. */
+    if (addr > SCBStatus && addr <= sizeof(s->mem) - sizeof(val)) {
         memcpy(&s->mem[addr], &val, sizeof(val));
     }
 
@@ -1476,9 +1444,6 @@ static void eepro100_write1(EEPRO100State * s, uint32_t addr, uint8_t val)
 
     switch (addr) {
     case SCBStatus:
-#if 0
-        eepro100_write_status(s, val);
-#endif
         break;
     case SCBAck:
         eepro100_acknowledge(s);
@@ -1510,7 +1475,8 @@ static void eepro100_write1(EEPRO100State * s, uint32_t addr, uint8_t val)
 
 static void eepro100_write2(EEPRO100State * s, uint32_t addr, uint16_t val)
 {
-    if (addr <= sizeof(s->mem) - sizeof(val)) {
+    /* SCBStatus is readonly. */
+    if (addr > SCBStatus && addr <= sizeof(s->mem) - sizeof(val)) {
         memcpy(&s->mem[addr], &val, sizeof(val));
     }
 
@@ -1518,9 +1484,7 @@ static void eepro100_write2(EEPRO100State * s, uint32_t addr, uint16_t val)
 
     switch (addr) {
     case SCBStatus:
-#if 0
-        eepro100_write_status(s, val);
-#endif
+        s->mem[SCBAck] = (val >> 8);
         eepro100_acknowledge(s);
         break;
     case SCBCmd:
@@ -1908,9 +1872,6 @@ static const VMStateDescription vmstate_eepro100 = {
         VMSTATE_UINT32(statistics.fc_rcv_unsupported, EEPRO100State),
         VMSTATE_UINT16(statistics.xmt_tco_frames, EEPRO100State),
         VMSTATE_UINT16(statistics.rcv_tco_frames, EEPRO100State),
-#if 0
-        VMSTATE_UINT16(status, EEPRO100State),
-#endif
         /* Configuration bytes. */
         VMSTATE_BUFFER(configuration, EEPRO100State),
         VMSTATE_END_OF_LIST()