Module Rpi.Mem

module Mem: sig .. end

Memory.

Note. All multi-bytes memory accesses are done in little endian order.

Addresses

type addr = nativeint

The type for byte addresses.

val (+) : addr -> addr -> addr

a + off adds off to a.

val (-) : addr -> addr -> addr

a - off subracts off to a.

val offset : addr -> int -> addr

offset addr n is add + Nativeint.of_int n.

val of_int32 : int32 -> addr

of_int32 i is the address corresponding to i.

val pp_addr : Format.formatter -> addr -> unit

pp_addr ppf a prints and unspecified reprsentation of a on ppf.

Memory barriers

val wait : int -> unit

wait n waits at least n CPU cycles.

val dsb : unit -> unit

dsb () performs a data synchronization barrier. Returns when all instructions before the call are complete.

val dmb : unit -> unit

dmb () performs a data memory barrier. Ensures that all explicit memory access before the call complete before any new explicit access made after the call.

val isb : unit -> unit

isb () performs an instruction synchronization barrier. Flushes the pipeline in the processor so that all instruction following the call are fetched from cache or memory.

Reads

val get : addr -> int

get a gets the byte at address a.

val get_int : addr -> int

get_int a gets the 4 bytes starting at address a.

Warning. Truncates the value of the 32nd bit.

val get_int32 : addr -> int32

get_int32 a gets the 4 bytes starting at address a.

val get_int64 : addr -> int64

get_int64 a gets the 8 bytes starting at address a.

Writes

val set : addr -> int -> unit

set a v sets the byte at address a to v.

val set_int : addr -> int -> unit

set a v sets the 4 bytes starting at address a to v.

val set_int32 : addr -> int32 -> unit

set a v sets the 4 bytes starting at address a to v.

val set_int64 : addr -> int64 -> unit

set a v sets the 8 bytes starting at address a to v.

Masked writes

val set_bits : addr -> bits:int -> int -> unit

set_bits is like Rpi.Mem.set but only affects the bits set in bits.

val set_int_bits : addr -> bits:int -> int -> unit

masked_set_int is like Rpi.Mem.set_int but only affects the bits set in bits.

val set_int32_bits : addr -> bits:int32 -> int32 -> unit

set_int32_bits is like Rpi.Mem.set_int32 but only affects the bits set in bits.

val set_int64_bits : addr -> bits:int64 -> int64 -> unit

set_int64_bits is like Rpi.Mem.set_int64 but only affects the bits set in bits.

Mapping

module Map: sig .. end

Memory maps