OpenRISC: Miscellaneous

OpenRISC Linux

==============

This is a port of Linux to the OpenRISC class of microprocessors; the initial

target architecture, specifically, is the 32-bit OpenRISC 1000 family (or1k).

For information about OpenRISC processors and ongoing development:

	website		http://openrisc.net

For more information about Linux on OpenRISC, please contact South Pole AB.

	email:		info@southpole.se

	website:	http://southpole.se

			http://southpoleconsulting.com

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Build instructions for OpenRISC toolchain and Linux

===================================================

In order to build and run Linux for OpenRISC, you'll need at least a basic

toolchain and, perhaps, the architectural simulator.  Steps to get these bits

in place are outlined here.

1)  The toolchain can be obtained from openrisc.net.  Instructions for building

a toolchain can be found at:

http://openrisc.net/toolchain-build.html

2) or1ksim (optional)

or1ksim is the architectural simulator which will allow you to actually run

your OpenRISC Linux kernel if you don't have an OpenRISC processor at hand.

	git clone git://openrisc.net/jonas/or1ksim-svn

	cd or1ksim

	./configure --prefix=$OPENRISC_PREFIX

	make

	make install

3)  Linux kernel

Build the kernel as usual

	make ARCH=openrisc defconfig

	make ARCH=openrisc

4)  Run in architectural simulator

Grab the or1ksim platform configuration file (from the or1ksim source) and

together with your freshly built vmlinux, run your kernel with the following

incantation:

	sim -f arch/openrisc/or1ksim.cfg vmlinux

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Terminology

===========

In the code, the following particles are used on symbols to limit the scope

to more or less specific processor implementations:

openrisc: the OpenRISC class of processors

or1k:     the OpenRISC 1000 family of processors

or1200:   the OpenRISC 1200 processor

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History

========

18. 11. 2003	Matjaz Breskvar (phoenix@bsemi.com)

	initial port of linux to OpenRISC/or32 architecture.

        all the core stuff is implemented and seams usable.

08. 12. 2003	Matjaz Breskvar (phoenix@bsemi.com)

	complete change of TLB miss handling.

	rewrite of exceptions handling.

	fully functional sash-3.6 in default initrd.

	a much improved version with changes all around.

10. 04. 2004	Matjaz Breskvar (phoenix@bsemi.com)

	alot of bugfixes all over.

	ethernet support, functional http and telnet servers.

	running many standard linux apps.

26. 06. 2004	Matjaz Breskvar (phoenix@bsemi.com)

	port to 2.6.x

30. 11. 2004	Matjaz Breskvar (phoenix@bsemi.com)

	lots of bugfixes and enhancments.

	added opencores framebuffer driver.

09. 10. 2010    Jonas Bonn (jonas@southpole.se)

	major rewrite to bring up to par with upstream Linux 2.6.36

The OpenRISC Linux port is fully functional and has been tracking upstream

since 2.6.35.  There are, however, remaining items to be completed within

the coming months.  Here's a list of known-to-be-less-than-stellar items

that are due for investigation shortly, i.e. our TODO list:

-- Implement the rest of the DMA API... dma_map_sg, etc.

-- Consolidate usage of memblock and bootmem... move everything over to

   memblock.

-- Finish the renaming cleanup... there are references to or32 in the code

   which was an older name for the architecture.  The name we've settled on is

   or1k and this change is slowly trickling through the stack.  For the time

   being, or32 is equivalent to or1k.

-- Implement optimized version of memcpy and memset

/*

 * OpenRISC asm-offsets.c

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * Modifications for the OpenRISC architecture:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 *

 * This program is used to generate definitions needed by

 * assembly language modules.

 *

 * We use the technique used in the OSF Mach kernel code:

 * generate asm statements containing #defines,

 * compile this file to assembler, and then extract the

 * #defines from the assembly-language output.

 */

#include <linux/signal.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/ptrace.h>

#include <linux/mman.h>

#include <linux/mm.h>

#include <linux/io.h>

#include <linux/thread_info.h>

#include <asm/page.h>

#include <asm/pgtable.h>

#include <asm/processor.h>

#define DEFINE(sym, val) \

		asm volatile("\n->" #sym " %0 " #val : : "i" (val))

#define BLANK() asm volatile("\n->" : : )

int main(void)

{

	/* offsets into the task_struct */

	DEFINE(TASK_STATE, offsetof(struct task_struct, state));

	DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));

	DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));

	DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));

	DEFINE(TASK_MM, offsetof(struct task_struct, mm));

	DEFINE(TASK_ACTIVE_MM, offsetof(struct task_struct, active_mm));

	/* offsets into thread_info */

	DEFINE(TI_TASK, offsetof(struct thread_info, task));

	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));

	DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));

	DEFINE(TI_KSP, offsetof(struct thread_info, ksp));

	DEFINE(PT_SIZE, sizeof(struct pt_regs));

	/* Interrupt register frame */

	DEFINE(STACK_FRAME_OVERHEAD, STACK_FRAME_OVERHEAD);

	DEFINE(INT_FRAME_SIZE, STACK_FRAME_OVERHEAD + sizeof(struct pt_regs));

	DEFINE(NUM_USER_SEGMENTS, TASK_SIZE >> 28);

	return 0;

}

/*

 * OpenRISC or32_ksyms.c

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * Modifications for the OpenRISC architecture:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 */

#include <linux/module.h>

#include <linux/elfcore.h>

#include <linux/sched.h>

#include <linux/in6.h>

#include <linux/interrupt.h>

#include <linux/vmalloc.h>

#include <linux/semaphore.h>

#include <asm/processor.h>

#include <asm/uaccess.h>

#include <asm/checksum.h>

#include <asm/io.h>

#include <asm/hardirq.h>

#include <asm/delay.h>

#include <asm/pgalloc.h>

#define DECLARE_EXPORT(name) extern void name(void); EXPORT_SYMBOL(name)

/* compiler generated symbols */

DECLARE_EXPORT(__udivsi3);

DECLARE_EXPORT(__divsi3);

DECLARE_EXPORT(__umodsi3);

DECLARE_EXPORT(__modsi3);

DECLARE_EXPORT(__muldi3);

DECLARE_EXPORT(__ashrdi3);

DECLARE_EXPORT(__ashldi3);

DECLARE_EXPORT(__lshrdi3);

EXPORT_SYMBOL(__copy_tofrom_user);