Retropie 4.x on Odroid C2

BuZz

@roleo you shouldn't need to modify config.mk afterwards - the raspberry pi link libs/video core stuff should only be added if the raspberry pi dev libs are present on the system - which shouldn't be the case.

are you building to run on X or framebuffer ?

roleo

@BuZz
I know but if I don't modify the config.mk the compilation process doesn't complete.
And I didn't find an option to disable videocore from configure.
Similar for OSS: the compilation is ok but the linker search for -lossaudio.
Maybe I missed a parameter?

I'm building on framebuffer, X is stopped.

BuZz

I will look into getting an ODroid-c2 board.

roleo

@BuZz
Is there a donation link?
I think there are a lot of users interested.

BuZz

@roleo https://retropie.org.uk/donate/

I have sent an email to Hardkernel to see if they would be interested in providing any development boards (as it would benefit them too). If not I will buy an ODroid-C2 to start with.

roleo

Update.
I compiled also lr-fbalpha adding the following section to makefile.libretro:

else ifeq ($(platform), armv8)
    TARGET := $(TARGET_NAME)_libretro.so
    fpic := -fPIC
    SHARED := -shared -Wl,-no-undefined -Wl,--version-script=$(LIBRETRO_DIR)
    PLATFORM_DEFINES += -march=armv8-a+crc -mcpu=cortex-a53 -ffast-math
    HAVE_NEON = 1
    ENDIANNESS_DEFINES := -DLSB_FIRST
    CFLAGS += -DARM

However I can not compile lr-imame4all.

roleo

Update.
lr-fceumm ok without problems.
lr-nestopia ok without problems.
lr-snes9x2010 ok adding the following section to Makefile.libretro:

# ARMv8
else ifneq (,$(findstring armv8,$(platform)))
	EXT    ?= so
	TARGET := $(TARGET_NAME)_libretro.$(EXT)
	SHARED := -shared -Wl,--no-undefined
	fpic := -fPIC
	CC   ?= gcc
	CFLAGS += -march=armv8-a+crc -mcpu=cortex-a53 -DARM
	ASFLAGS += -mcpu=cortex-a53

lr-imame4all compiles but doesn't work.
No chances with reicast: too asm parts...

BuZz

@roleo I have been generously offered an ODroid-C2 for free from Hardkernel so I will look into adding official support once it arrives. Thanks for your code feedback etc.

roleo

@BuZz
Good news!
I hope I can help you.

roleo

Update.
Finally I compiled the lr-imame4all. I encountered two problems:
1 - The libco (src/libretro/libretro-common/libco) gives an error at runtime: "longjmp causes uninitialized stack frame", so I had to use the ucontext.c part instead of sjlj.c modifying libco.c (could be a performance issue).
2 - The file src/libretro/osinline.h contains some asm code that I tried to patch (sorry but I'm not an asm programmer :) ).

This is the code I used for the lr-imame4all.sh script:

function sources_lr-imame4all() {
    gitPullOrClone "$md_build" https://github.com/libretro/mame2000-libretro.git
    sed -i 's/#include "sjlj.c"/#include "ucontext.c"/g' src/libretro/libretro-common/libco/libco.c
    sed -i 's/#include <retro_inline.h>/#include <retro_inline.h>\n#include <stdint.h>/g' src/libretro/osinline.h
    sed -i 's/    int res_hi, res_lo;/    int64_t res;/g' src/libretro/osinline.h
    sed -i 's/("smull\\t%1,%0,%2,%3"/("smull\\t%x0,%w1,%w2"/g' src/libretro/osinline.h
    sed -i 's/: "=r"(res_hi), "=r"(res_lo)/: "=r"(res)/g' src/libretro/osinline.h
    sed -i 's/return res_hi;/return res>>32;/g' src/libretro/osinline.h
    sed -i 's/( " mov %2, %2, asr #1 \\n"/( " asr %2, %2, #1 \\n"/g' src/libretro/osinline.h
}

mphil906

Hello,

I was able to compile emulationstation on my C2 successfully, but I get the following error when trying to run it:

lvl0:   Error initializing SDL!
        Failed to connect to the Mir Server
lvl0:   Renderer failed to initialize!
lvl0:   Window failed to intialize!

This error occurs if lightdm is stopped or running. Any ideas? I'm new so go easy on me.

roleo

@mphil906
During the build, the script has also built and installed libsdl mali-2.04?
Which libsdl2 packages are installed? You should have:

odroid@odroid64:~$ dpkg --list | grep sdl2
ii  libsdl2-2.0-0:arm64                   2.0.4+4mali                                   arm64        Simple DirectMedia Layer
hi  libsdl2-dev:arm64                     2.0.4+4mali                                   arm64        Simple DirectMedia Layer development files

from this source:
https://github.com/RetroPie/SDL-mirror/tree/mali-2.0.4
and not the original ones of ubuntu.

mphil906

@roleo
Thank you for the reply, I was able to compile emulationstation succesfully. Indeed, the default Ubuntu sdl was installed. I cloned the original posters repository. I'm not entirely sure if this was the issue, but in the function platform_odroid-c2() {...} __platform_flags did not contain mali. This is what I used:

function platform_odroid-c2() {
    __default_cflags="-O3 -march=armv8-a+crc -mtune=cortex-a53 -funsafe-math-optimizations"
    __default_asflags=""
    __default_makeflags="-j2"
    __platform_flags="armv8 neon mali" #added mali flag
    __qemu_cpu=cortex-a9
    __has_binaries=0
}

Not sure if this was the issue, but it compiles and runs. Thanks! Now attempting to compile retroarch.

BuZz

Just to note - I have a board now and will be looking at adding basic support as free time permits (ES + retroarch etc first).

roleo

@mphil906
I think this was the issue.

@BuZz
Great!
Thank you.

Shakz

@mphil906
See now I was just about to give up on this...dang...lemmie drag the darn thing out and give it another shot!
Thanks for posting!

roleo

With the last changes of the EmulationStation github I have a new problem during the configure phase:

cmake . -DFREETYPE_INCLUDE_DIRS=/usr/include/freetype2/

The cmake didn't find the vlc library.

CMake Error at CMake/Packages/FindVLC.cmake:33 (macro_ensure_version):
  MACRO_ENSURE_VERSION Macro invoked with incorrect arguments for macro
  named: MACRO_ENSURE_VERSION
Call Stack (most recent call first):
  CMakeLists.txt:51 (find_package)

--- EDIT ---

Sorry, my mistake.
The libvlc-dev was missing.

BuZz

I am currently working on odroid-c2 support - not trying to put you off working on it, but in case you don't want to duplicate efforts etc.

roleo

Apart reicast, I compiled everything I needed but I will continue to work on it for personal pleasure.
If I can help ...

Thanks for your support.

BuZz

@roleo Thanks.

Are you using the 16.04 aarch64 Ubuntu ? I was wondering as you are targetting aarch32 right ? Are you using an aarch32 targetted gcc ?

I was planning on targetting aarch64.

[edit] actually maybe I just misread - you will likely want to remove the "neon" platform flag though though if you have it as that's all aarch32 neon stuff which I don't think will work on aarch64 (without changes).