= GIET-VM / IOB Driver = 

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The [source:soft/giet_vm/giet_drivers/iob_driver.c iob_driver.c] and [source:soft/giet_vm/giet_drivers/iob_driver.h iob_driver.h] files define the IO driver. 

This ''vci_io_bridge'' component is a bridge allowing software to send configuration requests to external peripherals, and allowing external peripherals with a DMA capability to directly access the L3 cache (or external memory without passing through the L2 caches. This ''vci_io_bridge'' implement an IOMMU using a dedicated IOMMU page table.

This component should be implemented in the cluster specified by the (X_IO / Y_IO) variables in the hard_config.h file, and
the physical base address is (cluster_io << 32) | SEG_IOB_BASE. The SEG_IOB_BASE virtual addresses must be defined in hard_config.h file.

The addressables registers map, and the error codes are defined [source:soft/giet_vm/giet_drivers/iob_driver.h here].

 === void '''_iob_inval_tlb_entry'''( unsigned int cluster_xy,  unsigned int vaddr ) ===
This function invalidates a TLB entry identified by a virtual address, in the IOMMU.

 === void '''_iob_set_iommu_ptpr'''(  unsigned int cluster_xy,  unsigned int value ) ===
This function sets a new value in IOB_IOMMU_PTPR register.