#9 USBHwEPWrite accesses undefined memory

[Frank Buss]

When using USBHwEPWrite to write data lengths, which are not multiples of 4 bytes (e.g. string descriptors), it is possible that undefined memory is read. Would be better to use something like in USBHwEPRead.

[Bertrik Sikken]

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Originator: NO

Yes, I think this is probably a bug, although a minor one.

[Nobody/Anonymous]

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I used this solution:

int USBHwEPWrite(U8 bEP, U8 *pbBuf, int iLen)
{
int idx;
int USBTxDataTemp, i;

i = iLen;
idx = EP2IDX(bEP);

#ifdef DEBUG
//DBG("-EpW-");
#endif

// set write enable for specific endpoint
USBCtrl = WR_EN_BIT | ((bEP & 0xF) << 2);

// set packet length
USBTxPLen = iLen;

// write data
while (USBCtrl & WR_EN_BIT)
{
if (i >= 4)
{
USBTxData = (pbBuf[3] << 24) | (pbBuf[2] << 16) | (pbBuf[1] << 8) | pbBuf[0];
pbBuf += 4;
i -= 4;
}
else
{
for(USBTxDataTemp = 0; i > 0; i--)
{
USBTxDataTemp <<= 8;
USBTxDataTemp |= (pbBuf[i - 1]);
}
USBTxData = USBTxDataTemp;
}
}

// select endpoint and validate buffer

USBHwCmd(CMD_EP_SELECT | idx);
USBHwCmd(CMD_EP_VALIDATE_BUFFER);

return iLen;
}