/**
* Set up a DMA transfer.
* @param direction the direction of the transfer (DMA_READ or DMA_WRITE)
* @param chan the channel
* @param addr the address of the buffer
* @param size number of bytes to transfer
*/
void Setup_DMA(enum DMA_Direction direction, int chan, void *addr_,
ulong_t size) {
uchar_t mode = 0;
ulong_t addr = (ulong_t) addr_;
/* Make sure parameters are sensible */
KASSERT(direction == DMA_READ || direction == DMA_WRITE);
KASSERT(VALID_CHANNEL(chan));
KASSERT(IS_RESERVED(chan));
KASSERT(VALID_MEM(addr, size));
KASSERT(size > 0);
/* elaborate because the otherwise working test wouldn't work if the DMA region was precisely 64K page aligned. */
KASSERT0((((addr & 0xffff) == 0 && size <= 65536)) ||
(size <= (0xffff - (addr & 0xffff))),
"DMA region can't cross 64K boundary");
/* Set up transfer mode */
mode |= DMA_MODE_SINGLE;
mode |= (direction == DMA_READ) ? DMA_MODE_READ : DMA_MODE_WRITE;
mode |= (chan & 3);
if (chan == 5)
mode |= 0x10; /* nspring testing, make this better if useful. */
Debug("Setup_DMA(%s,%d,%x,%d)\n",
direction == DMA_READ ? "DMA_READ" : "DMA_WRITE", chan, addr, size);
Debug("Setup_DMA: mode=%02x\n", mode);
Debug("DMA_ADDR_REG for channel is %02x\n", DMA_ADDR_REG(chan));
Debug("DMA_PAGE_REG for channel is %02x\n", DMA_PAGE_REG(chan));
Debug("DMA_COUNT_REG for channel is %02x\n", DMA_COUNT_REG(chan));
/* Temporarily mask the DMA channel */
Mask_DMA(chan);
/* Write the transfer mode */
Out_Byte(DMA_MODE_REG(chan), mode);
/* Clear the byte pointer flip-flop */
Out_Byte(DMA_CLEAR_FF_REG(chan), 0); /* doesn't matter what value is written here */
/* Write the transfer address (LSB, then MSB) */
Out_Byte(DMA_ADDR_REG(chan), addr & 0xFF);
Out_Byte(DMA_ADDR_REG(chan), (addr >> 8) & 0xFF);
/* Write the page register */
Out_Byte(DMA_PAGE_REG(chan), (addr >> 16) & 0xFF);
/*
* Write the count (LSB, then MSB)
* Note that the count is one less that the number of bytes transferred
*/
if (chan > 4) {
size >>= 1;
} /* words not bytes? */
void Hardware_Shutdown() {
// works with > 1.3 qemu with the command line: -device isa-debug-exit,iobase=0x501
Out_Byte(0x501, 0x00);
// works on Bochs, and QEMU prior to 1.4
Out_Byte(0x8900, 'S');
Out_Byte(0x8900, 'h');
Out_Byte(0x8900, 'u');
Out_Byte(0x8900, 't');
Out_Byte(0x8900, 'd');
Out_Byte(0x8900, 'o');
Out_Byte(0x8900, 'w');
Out_Byte(0x8900, 'n');
KASSERT0(false,
"Hardware_Shutdown() failed: QEMU likely run with incorrect options.\n");
}
int Eth_Transmit(struct Net_Device *device, struct Net_Buf *nBuf,
uchar_t * destAddr, ushort_t type) {
struct Ethernet_Header header;
int rc;
KASSERT(Interrupts_Enabled());
/* all you have to do in this function is fill in the header. */
TODO_P(PROJECT_RAW_ETHERNET,
"construct the ethernet header for the destination, this device's address, and the type.");
rc = Net_Buf_Prepend(nBuf, &header, sizeof(header), NET_BUF_ALLOC_COPY);
if (rc != 0)
return rc;
ulong_t size = MAX(NET_BUF_SIZE(nBuf), ETH_MIN_DATA); /* buffer size must be at least ETH_MIN_DATA,
even if we don't use it. */
KASSERT0(size >= ETH_MIN_DATA, "input to Eth_Transmit should be at least ETH_MIN_DATA long"); /* paranoia. */
void *buffer = Malloc(size);
if (buffer == 0)
return ENOMEM;
rc = Net_Buf_Extract_All(nBuf, buffer);
if (rc != 0) {
Free(buffer);
return rc;
}
Disable_Interrupts();
device->transmit(device, buffer, size);
Enable_Interrupts();
return 0;
}
