//------------------------------------------------------------------------------
//
// Function: CS8900AGetFrame
//
UINT16 CS8900AGetFrame(UINT8 *pData, UINT16 *pLength)
{
UINT16 isq, length, status, count, data;
OALMSGS(OAL_ETHER&&OAL_VERBOSE, (
L"+CS8900AGetFrame(0x%08x, %d)\r\n", pData, *pLength
));
length = 0;
isq = INPORT16(&g_pCS8900->ISQ);
if ((isq & ISQ_ID_MASK) == RX_EVENT_ID && (isq & RX_EVENT_RX_OK) != 0) {
// Get RxStatus and length
status = INPORT16(&g_pCS8900->DATA0);
length = INPORT16(&g_pCS8900->DATA0);
if (length > *pLength) {
// If packet doesn't fit in buffer, skip it
data = ReadPacketPage(RX_CFG);
WritePacketPage(RX_CFG, data | RX_CFG_SKIP_1);
length = 0;
} else {
// Read packet data
count = length;
while (count > 1) {
data = INPORT16(&g_pCS8900->DATA0);
*(UINT16*)pData = data;
pData += sizeof(UINT16);
count -= sizeof(UINT16);
}
// Read last one byte
if (count > 0) {
data = INPORT16(&g_pCS8900->DATA0);
*pData = (UINT8)data;
}
}
}
// Return packet size
*pLength = length;
OALMSGS(OAL_ETHER&&OAL_VERBOSE, (
L"-CS8900AGetFrame(length = %d)\r\n", length
));
return length;
}
//------------------------------------------------------------------------------
//
// Function: CS8900AGetFrame
//
UINT16
CS8900AGetFrame(UINT8 *pData, UINT16 *pLength)
{
UINT16 isq, length, status, count, data;
UINT16 DeviceInterrupt;
BOOL GlobalInterrupt;
OALMSGS(OAL_ETHER && OAL_VERBOSE, (
L"+CS8900AGetFrame(0x%08x, %d)\r\n", pData, *pLength
));
//
// This routine could be interrupt driven, or polled.
// When polled, it keeps the emulator so busy that it
// starves other threads. The emulator already has the
// ability to recognize the polling in the bootloader
// by noting whether the interrupt for this device is
// disabled. In order to make the emulator recognize it
// here as well, we need to detect the polling by noting
// that *global* interrupts are disabled, then disable at
// the device level as well if so.
//
GlobalInterrupt = INTERRUPTS_ENABLE(FALSE); // Disable to obtain state
INTERRUPTS_ENABLE(GlobalInterrupt); // Immediately restore it.
// Mimic the global interrupt state at the device level too.
if (!GlobalInterrupt) // If polled
{
// Disable at the device level too so the emulator knows we're polling.
// Now it can yeild to other threads on the host side.
DeviceInterrupt = ReadPacketPage(BUS_CTL);
WritePacketPage(BUS_CTL, DeviceInterrupt & ~BUS_CTL_ENABLE_IRQ);
DeviceInterrupt &= BUS_CTL_ENABLE_IRQ;
}
length = 0;
isq = INPORT16(&g_pCS8900->ISQ);
if ((isq & ISQ_ID_MASK) == RX_EVENT_ID
&& (isq & RX_EVENT_RX_OK) != 0)
{
// Get RxStatus and length
status = INPORT16(&g_pCS8900->DATA0);
length = INPORT16(&g_pCS8900->DATA0);
if (length > *pLength)
{
// If packet doesn't fit in buffer, skip it
data = ReadPacketPage(RX_CFG);
WritePacketPage(RX_CFG, data | RX_CFG_SKIP_1);
length = 0;
} else {
// Read packet data
count = length;
while (count > 1)
{
data = INPORT16(&g_pCS8900->DATA0);
*(UINT16*)pData = data;
pData += sizeof *(UINT16*)pData;
count -= sizeof *(UINT16*)pData;
}
// Read last one byte
if (count > 0)
{
data = INPORT16(&g_pCS8900->DATA0);
*pData = (UINT8)data;
}
}
}
if (!GlobalInterrupt) // If polled
{
if (DeviceInterrupt) // If it was enabled at the device level,
{
// Re-enable at the device level.
CS8900AEnableInts();
}
}
// Return packet size
*pLength = length;
OALMSGS(OAL_ETHER && OAL_VERBOSE, (
L"-CS8900AGetFrame(length = %d)\r\n", length
));
return (length);
}
