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diff --git a/bsp_howto/ada95_interrupt.rst b/bsp_howto/ada95_interrupt.rst deleted file mode 100644 index f6fc0fc..0000000 --- a/bsp_howto/ada95_interrupt.rst +++ /dev/null @@ -1,75 +0,0 @@ -.. comment SPDX-License-Identifier: CC-BY-SA-4.0 - -.. COMMENT: COPYRIGHT (c) 1988-2008. -.. COMMENT: On-Line Applications Research Corporation (OAR). -.. COMMENT: All rights reserved. - -Ada95 Interrupt Support -####################### - -Introduction -============ - -This chapter describes what is required to enable Ada interrupt and error -exception handling when using GNAT over RTEMS. - -The GNAT Ada95 interrupt support RTEMS was developed by Jiri Gaisler -<jgais@ws.estec.esa.nl> who also wrote this chapter. - -Mapping Interrupts to POSIX Signals -=================================== - -In Ada95, interrupts can be attached with the interrupt_attach pragma. For -most systems, the gnat run-time will use POSIX signal to implement the -interrupt handling, mapping one signal per interrupt. For interrupts to be -propagated to the attached Ada handler, the corresponding signal must be raised -when the interrupt occurs. - -The same mechanism is used to generate Ada error exceptions. Three error -exceptions are defined: program, constraint and storage error. These are -generated by raising the predefined signals: SIGILL, SIGFPE and SIGSEGV. These -signals should be raised when a spurious or erroneous trap occurs. - -To enable gnat interrupt and error exception support for a particular BSP, the -following has to be done: - -- Write an interrupt/trap handler that will raise the corresponding signal - depending on the interrupt/trap number. - -- Install the interrupt handler for all interrupts/traps that will be handled - by gnat (including spurious). - -- At startup, gnat calls ``__gnat_install_handler()``. The BSP must provide - this function which installs the interrupt/trap handlers. - -Which CPU-interrupt will generate which signal is implementation defined. There -are 32 POSIX signals (1 - 32), and all except the three error signals (SIGILL, -SIGFPE and SIGSEGV) can be used. I would suggest to use the upper 16 (17 - 32) -which do not have an assigned POSIX name. - -Note that the pragma interrupt_attach will only bind a signal to a particular -Ada handler - it will not unmask the interrupt or do any other things to enable -it. This have to be done separately, typically by writing various device -register. - -Example Ada95 Interrupt Program -=============================== - -An example program (``irq_test``) is included in the Ada examples package to -show how interrupts can be handled in Ada95. Note that generation of the test -interrupt (``irqforce.c``) is BSP specific and must be edited. - -.. note:: - - The ``irq_test`` example was written for the SPARC/ERC32 BSP. - -Version Requirements -==================== - -With RTEMS 4.0, a patch was required to psignal.c in RTEMS sources (to correct -a bug associated to the default action of signals 15-32). The SPARC/ERC32 -RTEMS BSP includes the``gnatsupp`` subdirectory that can be used as an example -for other BSPs. - -With GNAT 3.11p, a patch is required for ``a-init.c`` to invoke the BSP -specific routine that installs the exception handlers. |