Documentation/Platforms/OpenRISC: Difference between revisions

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[[File:openrisc-system-boot-screenshot.png|400px|Linux booting up]]<span style="margin:20px;"></span>
[[File:openrisc-system-boot-screenshot.png|400px|Linux booting up]]<span style="margin:20px;"></span>
[[File:openrisc-system-commands-screenshot.png|400px|Linux command line execution]]<br><br>
[[File:openrisc-system-commands-screenshot.png|400px|Linux command line execution]]<br><br>
[[File:openrisc-user-screenshot.png|400px|Use more]]<br>
[[File:openrisc-user-screenshot.png|400px|User mode]]<br>


== Links ==
== Links ==
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== Contacts ==
== Contacts ==
Maintainer: [mailto:proljc@gmail.com Jia Liu]
Maintainer: [mailto:shorne@gmail.com Stafford Horne]

Revision as of 06:06, 25 February 2017

Description

OpenRISC is an open source processor architecture. While instruction sets like x86 are proprietary and owned by a single company, OpenRISC is free. Its main use is as a processor on an embedded system.

Full system emulation

To boot linux you can run the following. If you are starting out you can download the OpenRISC test image from Testing/System_Images.

 qemu-system-or1k -cpu or1200 -M or1k-sim -kernel $LINUX/vmlinux -serial stdio -nographic -monitor none

For networking support you can add the following options, note the open_eth option requires an out of tree driver from openrisc/linux.

 -device open_eth -netdev tap,id=or1k

User mode emulation

Using QEMU user mode emulation we can run and debug OpenRISC binaries on your host linux.

 $ cat main.c
 #include <stdio.h>
 int main() {
    printf ("hello\n");
    return 0;
 }
 $ or1k-linux-musl-gcc main.c
 # Here $LDPATH/lib/ld-musl-or1k.so.1 is linked to or1k-linux-musl/lib/libc.so
 $ qemu-or1k -L $LDPATH ./a.out 
 hello

Debugging Tips

For debugging openrisc can listen on a gdb stub port with the following options

 -gdb tcp::10001

To get good traces you can also add the following, this will output trace info to the file trace.txt

 -D trace.txt -d in_asm,exec,int,op_opt

Pictures

Linux booting up Linux command line execution

User mode

Links

Contacts

Maintainer: Stafford Horne