I'm interested, too. A Docker Image with everything setup would be the best in my opinion.

At work we have a little CoffeClock, which measures the weight of the coffee machine and show, how much is Coffee is left and how old the coffee is (little arduino project). I wanted to update it and add a website using my omega and python. For this I have to communicate with an HX711. I found a Python Class (https://gist.github.com/underdoeg/98a38b54f889fce2b237) which I modified. The problem is, that with onionGpio I need about 1ms to switch an output high and low.
The HX711 goes into power down state when the signal is high for more then 60µs ....
The question:

• is there an faster python module?
• are system calls to fastGPIO faster?
• should I forget about wasting time with Python and do it in C++?

Thanks Guys for your help!

@Boken-Lin I try to compile the new version and will play around with the toolchain a bit. If nothing helps I will go back. Thank's alot for your help. The Onion Omega is a great product and I really like to play around with it alot!

Sry I updated my post... so yes uClibc was kicked and uClibc-ng is in but only as broken package

@Boken-Lin

https://github.com/OnionIoT/OpenWRT-Packages/wiki/Setting-Up-the-Cross-Compile-Environment#step-2-get-openwrt-source

I believe I found the problem, in the current version of openWRT uClibc is available if broken packages are allowed. RIght now I compile the toolchain: toolchain-mips_34kc_gcc-5.2.0_uClibc-1.0.9
They switched to uClibc-ng-1.0.9

8e493a4b7c0749bf65cfd545ca18b384bc1d4f32    12/03/2015 03:47 PM
uClibc-ng: update to 1.0.9

Update to 1.0.9, switch to XZ tarball.

Signed-off-by: Waldemar Brodkorb <wbx@uclibc-ng.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47715 3c298f89-4303-0410-b956-a3cf2f4a3e73

b70a36d1d969f5aa9ad081c9a395633793582a5a  11/02/2015 07:12 PM

uclibc: remove version 0.9.33

Latest uClibc-ng is now the only supported option

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47357 3c298f89-4303-0410-b956-a3cf2f4a3e73

@Boken-Lin

Yeah I tried this before, too. But there is no option for uClibc....
May it be possible to poste a .conf with the right kernel settings?

Because the dependency for uClibc contains : .... && !mips [=y] && ....
and mips is set by: .... || TARGET_ar71xx_generic [=y] && <choice> && TARGET_ar71xx [=y] || ....

Thank you for your suggestion,

I know that a lot of people just use the SDK to compile programs, but I want to get the openWRT package CrossCompile environment to work. I want to create packages that I can install on the onion (.ipk packages if I'm remember correctly). I don't know how to get the toolchain you suggested into the openWRT environment, so if you have an Idea how to do that, it would be perfect

I mean someone compiles their packages with the correct toolchain/setup and provide this packages to us, don't they?

Hiho,
I want to compile a "helloWorld"-package with the openwrt standart setup found on: https://github.com/OnionIoT/OpenWRT-Packages/wiki/Setting-Up-the-Cross-Compile-Environment

The problem is, that with this setup a normal program links dynamically against: "ld-musl-mips-sf.so.1" but the onion has "ld-uClibc.so.0" installed. I know that a static linked program works, but in the end I don't want to get hello World to work

$ readelf -l helloWorld

Elf file type is EXEC (Executable file)
Entry point 0x400600
There are 9 program headers, starting at offset 52

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  PHDR           0x000034 0x00400034 0x00400034 0x00120 0x00120 R E 0x4
  INTERP         0x000154 0x00400154 0x00400154 0x0001a 0x0001a R   0x1
      [Requesting program interpreter: /lib/ld-musl-mips-sf.so.1]
  REGINFO        0x000170 0x00400170 0x00400170 0x00018 0x00018 R   0x4
  LOAD           0x000000 0x00400000 0x00400000 0x008f0 0x008f0 R E 0x10000
  LOAD           0x000fdc 0x00410fdc 0x00410fdc 0x00050 0x00074 RW  0x10000
  DYNAMIC        0x000188 0x00400188 0x00400188 0x00110 0x00110 RWE 0x4
  GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RW  0x10
  GNU_RELRO      0x000fdc 0x00410fdc 0x00410fdc 0x00024 0x00024 R   0x1
  NULL           0x000000 0x00000000 0x00000000 0x00000 0x00000     0x4

 Section to Segment mapping:
  Segment Sections...
   00     
   01     .interp 
   02     .reginfo 
   03     .interp .reginfo .dynamic .hash .dynsym .dynstr .gnu.version .gnu.version_r .rel.plt .init .text .MIPS.stubs .fini .rodata .eh_frame .plt 
   04     .ctors .dtors .got.plt .rld_map .got .sdata .bss 
   05     .dynamic 
   06     
   07     .ctors .dtors .got.plt 
   08     

After reading "https://community.onion.io/topic/9/how-to-install-gcc" I believe that this dynamic link is what caused the problem for Kit Bishop:

root@Omega:~# ls -l
-rwxrwxrwx    1 root     root          8994 Nov 18 12:26 testc
root@Omega:~# ./testc
-ash: ./testc: not found
root@Omega:~#

(Sry but I can't find a link to his post option :-()

I see that the tool chain uses the wrong stdLib, that path name of the tool chain looks like: "...toolchain-mips_34kc_gcc-5.2.0_musl-1.1.11/

I have the kernel settings on "Preferred standard C++ library (uClibc++) --->" but the other uClibc settings I can't activate because mips is set and I don't know where openwrt configures the tool chain std lib.

So the question is: How to configure the openwrt setup to compile programs for the existing onion os? How to use uClibc instead of musl?

Just for completness here are my helloWorld Makefile:

# build helloworld executable when user executes "make"

helloWorld: helloWorld.o
	@echo "\n\n----------------------\n\n"
	@echo "CXX: $(CXX)"
	@echo "CFLAGS: $(CFLAGS)"
	@echo "LDFLAGS: $(LDFLAGS)"
	@echo "LIB: $(LIB)"
	$(CXX) $(LDFLAGS) helloWorld.o -o helloWorld
helloWorld.o: helloWorld.c
	$(CXX) $(CXXFLAGS) -c helloWorld.c

all: helloWorld
clean:
	rm *.o helloWorld
	

and the openWRT project Makefile:

include $(TOPDIR)/rules.mk

PKG_NAME:=helloWorld
PKG_VERSION:=1
PKG_RELEASE:=1

# This specifies the directory where we're going to build the program.  
# The root build directory, $(BUILD_DIR), is by default the build_mipsel 
# directory in your OpenWrt SDK directory
PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)

include $(INCLUDE_DIR)/package.mk 

define Package/helloWorld
	SECTION:=alex
	CATEGORY:=alex
	TITLE:=HalloWorld
endef

define Package/helloWorld/description
	Hello World
endef

# Specify what needs to be done to prepare for building the package.
# In our case, we need to copy the source files to the build directory.
# This is NOT the default.  The default uses the PKG_SOURCE_URL and the
# PKG_SOURCE which is not defined here to download the source from the web.
# In order to just build a simple program that we have just written, it is
# much easier to do it this way.
define Build/Prepare
	mkdir -p $(PKG_BUILD_DIR)
	$(CP) /home/apit/projects/openwrt/helloWorld/* $(PKG_BUILD_DIR)/
endef

MAKE_OPTS:= \
    ARCH="$(LINUX_KARCH)" \
    CROSS_COMPILE="$(TARGET_CROSS)" \
    SUBDIRS="$(PKG_BUILD_DIR)"

define Package/helloWorld/Compile
	cd $(PKG_BUILD_DIR)

	#$(MAKE) -C $(PKG_BUILD_DIR) \
	#	LDFLAGS="$(EXTRA_LDFLAGS)" \
	#	CXXFLAGS="$(TARGET_CFLAGS) $(EXTRA_CPPFLAGS) -nostdinc++" \
	#	$(TARGET_CONFIGURE_OPTS) \
	#	CROSS="$(TARGET_CROSS)" \
	#	ARCH="$(ARCH)" \
	#	$(1);
	$(MAKE) -C $(PKG_BUILD_DIR) $(MAKE_OPTS)
	
endef

define Package/helloWorld/install
	$(INSTALL_DIR) $(1)/bin/
	$(INSTALL_BIN) $(PKG_BUILD_DIR)/helloWorld $(1)/bin/helloWorld
endef
$(eval $(call BuildPackage,helloWorld)) 

Of course alot of that lines are from openwrt hello world tutorials or from onion omega projects. I also remove some lines, so if it not compile its because I erased to much ... I tried to keep it clean here... sry.

PS: thanks alot for your help!

PSS: I found this statistic: http://www.etalabs.net/compare_libcs.html
Is it possible that compiling the os with musl is faster and smaller then with uClibc?