KasperskyOS Community Edition 1.1
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KnIoDmaMap()
This function is declared in the coresrv/io/dma.h file.
Retcode KnIoDmaMap(Handle rid, rtl_size_t offset, rtl_size_t length, void *hint,
int vmflags, void **addr, Handle *handle);
This function maps a DMA buffer area to the address space of a process.
Input parameters:
ridis the handle of the DMA buffer allocated usingKnIoDmaCreate().offsetrefers to the page-aligned offset of the start of the area from the start of the buffer, indicated in bytes.lengthrefers to the size of the area; it must be a multiple of the page size and must not exceed <buffer size -offset>.hintis the virtual address of the start of mapping; if it is equal to 0, the address is selected by the kernel.vmflagsrefers to allocation flags.
In the vmflags parameter, you can use the following allocation flags (vmm/flags.h):
- VMM_FLAG_READ and VMM_FLAG_WRITE are memory protection attributes.
- VMM_FLAG_LOW_GUARD and VMM_FLAG_HIGH_GUARD add a protective page before and after the allocated memory, respectively.
Permissible combinations of memory protection attributes:
- VMM_FLAG_READ allows reading page contents.
- VMM_FLAG_WRITE allows modification of page contents.
- VMM_FLAG_READ | VMM_FLAG_WRITE allows reading and modifying page contents.
Output parameters:
addris the pointer to the virtual address of the start of the mapped area.handlerefers to the handle of the created mapping.
If successful, the function returns rcOk.
For a usage example, see KnIoDmaCreate().
To delete a created mapping, you must call the KnIoClose() function and pass the specified mapping handle in this function.