Module Rpi.Mbox

module Mbox: sig .. end

Mailboxes.

Mailbox allow to connect with the RPi's GPU which is in charge of a lot the bookkeeping.

This is not very well documented, a bit of documentation can be found here. Using the property interface should be enough.

Property interface

module Prop: sig .. end

Property interface

Channels

type channel =

`\|`	`Power_management`
`\|`	`Framebuffer`
`\|`	`Virtual_UART`
`\|`	`VCHIQ`
`\|`	`LEDs`
`\|`	`Buttons`
`\|`	`Touchscreen`
`\|`	`Unused`
`\|`	`Tags_ARM_to_VC`
`\|`	`Tags_VC_to_ARM`

The type for mailbox channels

Communicating addresses

Warning The lowest 4-bits of sent addresses can't be read by the GPU as they are used to transmit the channel. used. As such addresses must be aligned on 16 bytes.

val read : channel -> Rpi.Mem.addr

read c reads the address of channel c.

val write : channel -> Rpi.Mem.addr -> unit

write c a writes the v to the channel c.