[LinuxBIOS] RFC Winflashrom Architecture -- Current device driver (testbed)

[Darmawan Salihun]

Peter Stuge wrote:
> On Wed, Jun 06, 2007 at 11:16:03PM +0700, Darmawan Salihun wrote:
>   
>>> 1. Kernel driver allowing unrestricted reads and writes to top 16MB.
>>>       
>> The current version of the driver code is capable of mapping
>> *anywhere* within the 4GB physical address space. It shouldn't be a
>> problem to restrict it to the top 16MB.
>>     
>
> We should make that 2MB until we actually support larger flash parts
> btw.
>
>   
ok, no problem.

>> The logic of the mapping process is as follows:
>>  a. The physical memory address range is mapped into the kernel's
>> virtual memory address range
>> b. The kernel's virtual memory address range is then mapped to the
>> "requesting" user mode virtual memory address range.
>>     
>
> Sounds good.
>
>   
For those interested in the driver code attached previously.
The bulk of the work is carried out in two functions, i.e. 

NTSTATUS MapMmio(PDEVICE_OBJECT pDO, PIRP pIrp)
/*++
Routine Description:
    Process the IRPs with IOCTL_MAP_MMIO code. 
    This routine maps a physical address range 
    to the usermode application address space. 
    
Arguments:
    pDO - pointer to the device object of this driver.
    pIrp - pointer to an I/O Request Packet.

Return Value:
    NT Status code

Notes:
    This function can only map the area 
    below the 4-GB limit.
--*/



and


NTSTATUS CleanupMmioMapping(PDEVICE_EXTENSION pDevExt, ULONG i)
/*++
Routine Description:
    This routine cleanup the mapping of a MMIO range 
    and resources it consumes.
    
Arguments:
    pDevExt - pointer to the device extension of the driver
    i - index of the mapZone to cleanup

Return Value:
    NT Status code
--*/


That's all for now.

--Darmawan Salihun