meta-curios usage

This is used for generating SDK or Linux image for the Xiphos Q7S board for the CuRIOS project. Q7S is the space-qualified version of Q7, but note that Q7 is revc1 whereas Q7S is revb. The lab Xiphos is Q7. The flight Xiphos is Q7S. Generally, the recipes in this layer can also be used for other yocto projects, which requires these software packages to be pre-installed.

Generate SDK

1. clone the Xiphos's yocto repo

git clone --depth 1 -b xiphos-v2021.2 git@trac.xiphos.com:xiphos/yocto.git yocto-xiphos

Note: You have to add your ssh public to the Xiphos git system, or you won't be able to clone the repo in this way.

2. clone this repo to the yocto-xiphos/yocto

cd yocto-xiphos/yocto
git clone https://github.com/liuweiseu/meta-curios.git

3. create the q7s-build dir

. setup-environment q7s-build

If everything goes well, the q7s-build dir should be create automaticlly, and you should be in the q7s-build dir now.

4. edit the conf file

cd q7s-build
vim conf/local.conf

# (1) add `PREMIRRORS`
PREMIRRORS = " \
  git://.*/.* file://${ABSOLUTE_PATH_TO_DOWNLOADS} \ 
  gitsm://.*/.* file://${ABSOLUTE_PATH_TO_DOWNLOADS} \ 
  http://.*/.* file://${ABSOLUTE_PATH_TO_DOWNLOADS} \ 
  "
# (1) add the following line
IMAGE_INSTALL_append = "cfitsio"

Note: You need to modify ${ABSOLUTE_PATH_TO_DOWNLOADS} to the absolute path of the xsc-downloads folder on your machine.
Here is an example of the conf/local.conf on my machine:

MACHINE ?= "q7s-revb"
...
PREMIRRORS = " \
  git://.*/.* file:///home/wei/yocto-xiphos/xsc-downloads \ 
  gitsm://.*/.* file:///home/wei/yocto-xiphos/xsc-downloads \ 
  http://.*/.* file:///home/wei/yocto-xiphos/xsc-downloads \ 
  "
IMAGE_INSTALL_append = "cfitsio"

Note:
(1) To build the image/SDK for "q7s-revc" board (lab Xiphos), you need to set MACHINE ?= "q7s-revc". Use q7s-revb for the flight model;
(2) To install the SDK on a ARM64 platform, you need to add SDKMACHINE = "aarch64" to the conf/local.conf; if the SDK is for a x86-64 platform, you need to add SDKMACHINE = "x86_64";
(3) There is a bug in yocto-xiphos-v2021.1(v3.3.0 or earlier), which pops up error messages during SDK generation. To fix the error, you need to add the following lines to the conf/local/conf:

    TOOLCHAIN_TARGET_TASK_remove = "xsc-rmap-dev"
    TOOLCHAIN_TARGET_TASK_remove += "xsc-rmap-staticdev"
    TOOLCHAIN_TARGET_TASK_remove += "libhrestime-staticdev"

5. add meta-curios layer to the project

bitbake-layers add-layer ../meta-curios

6. generate SDK

bitbake xsc-image-minimal -c populate_sdk

If the SDK is generated successfully, you will see this file: tmp-glibc/deploys/sdk/xxx.sh.
The xxx.sh file is the sdk installer.
In this project, the sdk installer file is ark-glibc-x86_64-xsc-image-minimal-cortexa9hf-neon-toolchain-nodistro.0.sh.
The pre-generated SDK installer is here.

Use the SDK

1. install SDK

sudo sh ./ark-glibc-x86_64-xsc-image-minimal-cortexa9hf-neon-toolchain-nodistro.0.sh

# You will see the following messages:
ark (Xiphos Systems Reference Distribution) SDK installer version nodistro.0
============================================================================
Enter target directory for SDK (default: /opt/xiphos/sdk/ark):
You are about to install the SDK to "/opt/xiphos/sdk/ark". Proceed[Y/n]? Y
Extracting SDK...............................done
Setting it up...done
SDK has been successfully set up and is ready to be used.
Each time you wish to use the SDK in a new shell session, you need to source the environment setup script e.g.
$ . /opt/xiphos/sdk/ark/environment-setup-cortexa9hf-neon-xiphos-linux-gnueabi

The default installation path is /opt/xiphos/sdk/ark. You could install the SDK to anywhere you want.
Note: The SDK installer has to be copied to your host machine.

2. source the environment setup script

. /opt/xiphos/sdk/ark/environment-setup-cortexa9hf-neon-xiphos-linux-gnueabi

If everything goes well, you should see $CC is setup:

echo $CC

arm-xiphos-linux-gnueabi-gcc -march=armv7-a -marm -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9 --sysroot=/opt/xiphos/sdk/ark/sysroots/cortexa9hf-neon-xiphos-linux-gnueabi

3. cross compile your code with the SDK
   Let's assume you want to cross compile test.c, so you just need to do:

$CC test.c -o test

Now, you should get the cross-compiled exectuble file: test.