GIET-VM / Physical addressing functions

The utils.c​ and util.h​ files define the functions supporting physical addressing, using the CP2_PADDR_EXT register. Physical addresses can have up to 64 bits.

They are prefixed by "_" to remind that they can only be executed by a processor in kernel mode.

unsigned int _physical_read( unsigned long long paddr )

Returns the 32 bits word stored at physical address paddr, after a temporary DTLB deactivation. It uses the CP2_PADDR_EXT register.

void _physical_write( unsigned long long paddr, unsigned int value )

Writes the 32 bits word value at physical address paddr, after a temporary DTLB deactivation. It uses the CP2_PADDR_EXT register.

unsigned long long _physical_read_ull( unsigned long long paddr )

Returns the 64 bits word stored at physical address paddr, after a temporary DTLB deactivation. It uses the CP2_PADDR_EXT register.

void _physical_write_ull( unsigned long long paddr, unsigned long long value )

Writes the 64 bits word value at physical address paddr, after a temporary DTLB deactivation. It uses the CP2_PADDR_EXT register.

void _physical_memcpy( unsigned long long dst_paddr, unsigned long long src paddr, unsigned int size )

This function makes a memcpy from a source buffer to a destination buffer, using physical addresses, after a temporary DTLB de-activation. The src_paddr, dst_paddr and size arguments must be multiple of 4 bytes.

unsigned int _io_extended_read( unsigned int* vaddr )

This function is used by the GIET-VM drivers to read a 32 bits word in a peripheral register. If the MMU is not activated, the virtual address is extended using X_IO and Y_IO (defined in the hard-config.h file) to reach the cluster_io.

void _io_extended_write( unsigned int* vaddr, unsigned int value )

This function is used by the GIET-VM drivers to write a 32 bits word in a peripheral register. If the MMU is not activated, the virtual address is extended using X_IO and Y_IO (defined in the hard-config.h file) to reach the cluster_io.