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HP OpenVMS Systemsask the wizard |
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The Question is:
The following driver function for direct I/O produces sporadically
the bugcheck error INVALID PAGE TABLE ENTRY FORMAT
in the ioc$load_map function.
I believe that the code conformes to the documention
"OpenVMS Alpha Guide yo Upgrading Priviledged-Code
Applications" .
Thank you very much in advance for any hint.
Yours sincerely
Kar. H. Degenhardt
/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Read data by DMA
(function is defined with DIRECT_64 flag)
--------------------------------------------------------------*/
int ck$dma_operation (IRP *irp, PCB *pcb, *ucb, CCB *ccb)
CHAR_PQ qio_bufp;
int buflen;
...
/* get user buffer address and length */
qio_bufp = (CHAR_PQ)irp->irp$q_qio_p1;
count = irp->irp$l_qio_p2;
buflen = 4*count;
...
/* Check write access to user buffer and lock buffer in memory */
status = exe_std$readlock(irp,pcb,ucb,ccb,(VOID_PQ)qio_bufp,buflen,0);
if (! $VMS_STATUS_SUCCESS(status))
return (call_abortio(irp,pcb,ucb,status));
...
/* get crctx and set item count*/
crab = adp->adp$l_crab;
status = ioc$alloc_crctx(crab,&crctx,0);
if (! $VMS_STATUS_SUCCESS(status))
return (call_abortio(irp,pcb,ucb,status));
crctx->crctx$l_item_cnt = (buflen >> 13) + 2;
/* get resources */
status = ioc$alloc_cnt_res(crab,crctx,0,0,0);
if (! $VMS_STATUS_SUCCESS(status))
{
status = ioc$dealloc_crctx(crctx);
return (call_abortio(irp,pcb,ucb,status));
}
/* load map registers */
status = ioc$load_map(adp,crctx,irp->irp$l_svapte,
irp->irp$l_boff, (void **)&dma_base);
if (! $VMS_STATUS_SUCCESS(status))
{
status = ioc$dealloc_cnt_res(adp->adp$l_crab, crctx);
status = ioc$dealloc_crctx(crctx);
return (call_abortio(irp,pcb,ucb,status));
}
...
return (call_qiodrvpkt(irp, ucb));
return (call_finishio(irp, ucb, status, 0));
The Answer is : Without a rather more detailed investigation involving a complete source example of the driver and an example of the crash, an answer is difficult. The OpenVMS Wizard would encourage contact with the Compaq Customer Support Center.
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