android_kernel_motorola_sm6225/arch/avr32/lib/clear_user.S
Haavard Skinnemoen 5f97f7f940 [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>
2006-09-26 08:48:54 -07:00

76 lines
1.2 KiB
ArmAsm

/*
* Copyright 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/page.h>
#include <asm/thread_info.h>
#include <asm/asm.h>
.text
.align 1
.global clear_user
.type clear_user, "function"
clear_user:
branch_if_kernel r8, __clear_user
ret_if_privileged r8, r12, r11, r11
.global __clear_user
.type __clear_user, "function"
__clear_user:
mov r9, r12
mov r8, 0
andl r9, 3, COH
brne 5f
1: sub r11, 4
brlt 2f
10: st.w r12++, r8
sub r11, 4
brge 10b
2: sub r11, -4
reteq 0
/* Unaligned count or address */
bld r11, 1
brcc 12f
11: st.h r12++, r8
sub r11, 2
reteq 0
12: st.b r12++, r8
retal 0
/* Unaligned address */
5: cp.w r11, 4
brlt 2b
lsl r9, 2
add pc, pc, r9
13: st.b r12++, r8
sub r11, 1
14: st.b r12++, r8
sub r11, 1
15: st.b r12++, r8
sub r11, 1
rjmp 1b
.size clear_user, . - clear_user
.size __clear_user, . - __clear_user
.section .fixup, "ax"
.align 1
18: sub r11, -4
19: retal r11
.section __ex_table, "a"
.align 2
.long 10b, 18b
.long 11b, 19b
.long 12b, 19b
.long 13b, 19b
.long 14b, 19b
.long 15b, 19b