Hi,all.
I'm developping directdraw driver in wince6.
I has alloced some system memory as video memory in config.bib
Normally, the video memory is alloced in AllocSurface function whe
create new surface. And the HalLock function write the video memor
virtual address (it is 0xAxxxxxxx) to corresponding parameter.In app
the Lock function can get the virtual address in user space (it mayb
0x0001xxxx). The OS convert the video memory virtual address to th
user space virtual address automatically . App can access the surfac
through the user space virtual address.
During lacking video memory, I want to alloc the system memory as vide
memory dynamic through the AllocPhysMem function . The function retur
the kernel space virtual address(0xDxxxxxxx).And the HalLock functio
write the addressto corresponding parameter.The Lock app function jus
get the kernel space virtual address(0xDxxxxxxx). The OS doesn'
convert the kernel space virtual address to the user space virtua
address automatically. Why