[PATCH] avr32 architecture

This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.

AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density.  The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.

The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf

The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture.  It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit.  It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.

Full data sheet is available from

http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf

while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf

Information about the AT32STK1000 development board can be found at

http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918

including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.

Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.

This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.

[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/avr32/kernel/switch_to.S b/arch/avr32/kernel/switch_to.S
new file mode 100644
index 000000000000..a48d046723c5
--- /dev/null
+++ b/arch/avr32/kernel/switch_to.S
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <asm/sysreg.h>
+
+        .text
+        .global __switch_to
+        .type   __switch_to, @function
+
+        /* Switch thread context from "prev" to "next", returning "last"
+         *   r12 :      prev
+         *   r11 :      &prev->thread + 1
+         *   r10 :      &next->thread
+         */
+__switch_to:
+        stm     --r11, r0,r1,r2,r3,r4,r5,r6,r7,sp,lr
+        mfsr    r9, SYSREG_SR
+        st.w    --r11, r9
+        ld.w    r8, r10++
+        /*
+         * schedule() may have been called from a mode with a different
+         * set of registers. Make sure we don't lose anything here.
+         */
+        pushm   r10,r12
+        mtsr    SYSREG_SR, r8
+        frs                     /* flush the return stack */
+        sub     pc, -2          /* flush the pipeline */
+        popm    r10,r12
+        ldm     r10++, r0,r1,r2,r3,r4,r5,r6,r7,sp,pc
+        .size   __switch_to, . - __switch_to