/* Initialize the memory buffer including its checksum.
* No changes alloed to the header and the tail after that.
*/
HGSMIOFFSET HGSMIBufferInitializeSingle (const HGSMIAREA *pArea,
HGSMIBUFFERHEADER *pHeader,
HGSMISIZE cbBuffer,
uint8_t u8Channel,
uint16_t u16ChannelInfo)
{
if (cbBuffer < HGSMIBufferMinimumSize ())
{
return HGSMIOFFSET_VOID;
}
return hgsmiBufferInitializeSingle (pArea, pHeader, cbBuffer - HGSMIBufferMinimumSize (), u8Channel, u16ChannelInfo);
}
/* Initialize the memory buffer including its checksum.
* No changes alloed to the header and the tail after that.
*/
HGSMIOFFSET HGSMIBufferInitializeSingle(const HGSMIAREA *pArea,
HGSMIBUFFERHEADER *pHeader,
HGSMISIZE cbBuffer,
uint8_t u8Channel,
uint16_t u16ChannelInfo)
{
if ( !pArea
|| !pHeader
|| cbBuffer < HGSMIBufferMinimumSize())
{
return HGSMIOFFSET_VOID;
}
/* Buffer must be within the area:
* * header data size do not exceed the maximum data size;
* * buffer address is greater than the area base address;
* * buffer address is lower than the maximum allowed for the given data size.
*/
HGSMISIZE cbMaximumDataSize = pArea->offLast - pArea->offBase;
uint32_t u32DataSize = cbBuffer - HGSMIBufferMinimumSize();
if ( u32DataSize > cbMaximumDataSize
|| (uint8_t *)pHeader < pArea->pu8Base
|| (uint8_t *)pHeader > pArea->pu8Base + cbMaximumDataSize - u32DataSize)
{
return HGSMIOFFSET_VOID;
}
HGSMIOFFSET offBuffer = HGSMIPointerToOffset(pArea, pHeader);
pHeader->u8Flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE;
pHeader->u32DataSize = u32DataSize;
pHeader->u8Channel = u8Channel;
pHeader->u16ChannelInfo = u16ChannelInfo;
RT_ZERO(pHeader->u.au8Union);
HGSMIBUFFERTAIL *pTail = HGSMIBufferTailFromPtr(pHeader, u32DataSize);
pTail->u32Reserved = 0;
pTail->u32Checksum = HGSMIChecksum(offBuffer, pHeader, pTail);
return offBuffer;
}
int HGSMIAreaInitialize (HGSMIAREA *pArea, void *pvBase, HGSMISIZE cbArea, HGSMIOFFSET offBase)
{
uint8_t *pu8Base = (uint8_t *)pvBase;
if ( !pArea /* Check that the area: */
|| cbArea < HGSMIBufferMinimumSize () /* Large enough. */
|| pu8Base + cbArea < pu8Base /* No address space wrap. */
|| offBase > UINT32_C(0xFFFFFFFF) - cbArea /* Area within the 32 bit space: offBase + cbMem <= 0xFFFFFFFF */
)
{
return VERR_INVALID_PARAMETER;
}
pArea->pu8Base = pu8Base;
pArea->offBase = offBase;
pArea->offLast = cbArea - HGSMIBufferMinimumSize () + offBase;
pArea->cbArea = cbArea;
return VINF_SUCCESS;
}
