From d755cbd36f5b4410994bcd468aee983471ab7167 Mon Sep 17 00:00:00 2001 From: Amar Takhar Date: Sat, 16 Jan 2016 20:13:02 -0500 Subject: Split document into seperate files by section. --- cpu_supplement/ephiphany.rst | 91 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 cpu_supplement/ephiphany.rst (limited to 'cpu_supplement/ephiphany.rst') diff --git a/cpu_supplement/ephiphany.rst b/cpu_supplement/ephiphany.rst new file mode 100644 index 0000000..519c3e5 --- /dev/null +++ b/cpu_supplement/ephiphany.rst @@ -0,0 +1,91 @@ +Epiphany Specific Information +############################# + +This chapter discusses the`Epiphany Architecture `_ +dependencies in this port of RTEMS. Epiphany is a chip that can come with 16 and +64 cores, each of which can run RTEMS separately or they can work together to +run a SMP RTEMS application. + +**Architecture Documents** + +For information on the Epiphany architecture refer to the`Epiphany Architecture Reference `_. + +Calling Conventions +=================== + +Please refer to the`Epiphany SDK `_ +Appendix A: Application Binary Interface + +Floating Point Unit +------------------- + +A floating point unit is currently not supported. + +Memory Model +============ + +A flat 32-bit memory model is supported, no caches. Each core has its own 32 KiB +strictly ordered local memory along with an access to a shared 32 MiB external +DRAM. + +Interrupt Processing +==================== + +Every Epiphany core has 10 exception types: + +- Reset + +- Software Exception + +- Data Page Fault + +- Timer 0 + +- Timer 1 + +- Message Interrupt + +- DMA0 Interrupt + +- DMA1 Interrupt + +- WANT Interrupt + +- User Interrupt + +Interrupt Levels +---------------- + +There are only two levels: interrupts enabled and interrupts disabled. + +Interrupt Stack +--------------- + +The Epiphany RTEMS port uses a dedicated software interrupt stack. +The stack for interrupts is allocated during interrupt driver initialization. +When an interrupt is entered, the _ISR_Handler routine is responsible for +switching from the interrupted task stack to RTEMS software interrupt stack. + +Default Fatal Error Processing +============================== + +The default fatal error handler for this architecture performs the +following actions: + +- disables operating system supported interrupts (IRQ), + +- places the error code in ``r0``, and + +- executes an infinite loop to simulate a halt processor instruction. + +Symmetric Multiprocessing +========================= + +SMP is not supported. + +.. COMMENT: COPYRIGHT (c) 1988-2002. + +.. COMMENT: On-Line Applications Research Corporation (OAR). + +.. COMMENT: All rights reserved. + -- cgit v1.2.3