Make runqemu knows nothing about machine

Hello,

The qemu-native can boot a lot of machines, but oe-core's runqemu can only
boot a few of them which are hardcoded into runqemu. I'd like to change
it little to make it drop the hardcode and can boot more machines. Here
are some basic thoughts, please feel free to give your comments.

runqemu is a helpful script which can help us boot images easily, but it
has a lot of hard code for machine + args. I'd like to remove these from
runqemu, and make it as a frame. The logical is that, who knows clearly
about whether qemu can boot the machine and how to boot it (args), the
answer is the machine/bsp developer, so we can:

* Add a var like QEMU_SUPPORTED = "yes/no" in the bsp conf file (default to no)
* Add a var like QEMU_BOOT_ARGS = "foo" if there are special args.
* Let do_rootfs or do_image_foo write data such as QEMU_BOOT_ARGS to DEPLOY_DIR_IMAGE/runqemu/ or tmp/deploy/images/runqemu/, we can
treat
the "runqemu/" dir as a database, and anything we need there, for
example,
efi/pcbios, root args, and so on. We won't miss anything since all
the
images which can be boot by runqemu are built by oe-core.
* Then we can easily add supported machine to runqemu from the bsp itself
without change runqemu.

I will start working on it if there is no objections, and make sure it won't
break any current supported machines.

Quoted 35 lines · Robert Yang

Hello,

The qemu-native can boot a lot of machines, but oe-core's runqemu can only
boot a few of them which are hardcoded into runqemu. I'd like to change
it little to make it drop the hardcode and can boot more machines. Here
are some basic thoughts, please feel free to give your comments.

runqemu is a helpful script which can help us boot images easily, but it
has a lot of hard code for machine + args. I'd like to remove these from
runqemu, and make it as a frame. The logical is that, who knows clearly
about whether qemu can boot the machine and how to boot it (args), the
answer is the machine/bsp developer, so we can:

* Add a var like QEMU_SUPPORTED = "yes/no" in the bsp conf file (default to no)
* Add a var like QEMU_BOOT_ARGS = "foo" if there are special args.
* Let do_rootfs or do_image_foo write data such as QEMU_BOOT_ARGS to DEPLOY_DIR_IMAGE/runqemu/ or tmp/deploy/images/runqemu/, we can
treat
the "runqemu/" dir as a database, and anything we need there, for
example,
efi/pcbios, root args, and so on. We won't miss anything since all
the
images which can be boot by runqemu are built by oe-core.
* Then we can easily add supported machine to runqemu from the bsp itself
without change runqemu.

Quoted 3 lines

I will start working on it if there is no objections, and make sure it won't
break any current supported machines.

I guess we have some decisions to make. Firstly, is that script better in shell or python at this point? Originally, shell made sense but I'm starting to wonder if it would be clearer in python.

If we left it as shell, I'd envisaged it going through something like BBPATH and sourcing files from each of the layers to build up its own list of supported machines. The trouble is we can't easily get BBPATH in the shell environment since we can't assume bitbake and we ideally want it to work outside of our build environment.

With the development of devtool, I'm wondering if runqemu should become another such "command", written in python and working in any of the environments we'd expect devtool to work (eSDK, main build). If we did that, we'd have the layers and could easily access BBPATH and search for additional modules to add support for additional machines.

Thoughts?

Cheers,

Richard

Quoted 44 lines · Richard Purdie

Quoted 35 lines · Robert Yang

Hello,

The qemu-native can boot a lot of machines, but oe-core's runqemu can only
boot a few of them which are hardcoded into runqemu. I'd like to change
it little to make it drop the hardcode and can boot more machines. Here
are some basic thoughts, please feel free to give your comments.

runqemu is a helpful script which can help us boot images easily, but it
has a lot of hard code for machine + args. I'd like to remove these from
runqemu, and make it as a frame. The logical is that, who knows clearly
about whether qemu can boot the machine and how to boot it (args), the
answer is the machine/bsp developer, so we can:

* Add a var like QEMU_SUPPORTED = "yes/no" in the bsp conf file (default to no)
* Add a var like QEMU_BOOT_ARGS = "foo" if there are special args.
* Let do_rootfs or do_image_foo write data such as QEMU_BOOT_ARGS to DEPLOY_DIR_IMAGE/runqemu/ or tmp/deploy/images/runqemu/, we can
treat
the "runqemu/" dir as a database, and anything we need there, for
example,
efi/pcbios, root args, and so on. We won't miss anything since all
the
images which can be boot by runqemu are built by oe-core.
* Then we can easily add supported machine to runqemu from the bsp itself
without change runqemu.

Quoted 3 lines

I will start working on it if there is no objections, and make sure it won't
break any current supported machines.

I guess we have some decisions to make. Firstly, is that script better in shell or python at this point? Originally, shell made sense but I'm starting to wonder if it would be clearer in python.

Quoted 5 lines

If we left it as shell, I'd envisaged it going through something like BBPATH and sourcing files from each of the layers to build up its own list of supported machines. The trouble is we can't easily get BBPATH in the shell environment since we can't assume bitbake and we ideally want it to work outside of our build environment.

Thanks for the reply, my thought is that move part of the implementation into a class called runqemu.bbclass (or other names), and leave the runqemu as a shell script, when QEMU_BOOT_SUPPORTED = "1", runqemu.bbclass will create a:
tmp/deploy/images/<machine>/runqemu

And the content in runqemu can be: (for example, arm) QEMU="/path/to/sysroots/x86_64-linux/usr/bin/qemu-system-arm -m 128 -machine versatilepb "
TUNE_ARCH="arm"
QEMU_DEFAULT_KERNEL="zImage-qemuarm.bin" QEMU_DEFAULT_FSTYPE="ext4"
QEMU_MEM="-m 128"
[maybe more]

All of these variables can be defined in bsp layer or conf files. I will add some default values there according to TUNE_ARCH, so that the bsp may not need do anything to boot from qemu when QEMU_BOOT_SUPPORTED = "1".

// Robert

Quoted 15 lines

With the development of devtool, I'm wondering if runqemu should become another such "command", written in python and working in any of the environments we'd expect devtool to work (eSDK, main build). If we did that, we'd have the layers and could easily access BBPATH and search for additional modules to add support for additional machines.

Thoughts?

Cheers,

Richard

Quoted 59 lines · Robert Yang

Quoted 44 lines · Richard Purdie

Quoted 35 lines · Robert Yang

Hello,

The qemu-native can boot a lot of machines, but oe-core's runqemu can only
boot a few of them which are hardcoded into runqemu. I'd like to change
it little to make it drop the hardcode and can boot more machines. Here
are some basic thoughts, please feel free to give your comments.

runqemu is a helpful script which can help us boot images easily, but it
has a lot of hard code for machine + args. I'd like to remove these from
runqemu, and make it as a frame. The logical is that, who knows clearly
about whether qemu can boot the machine and how to boot it (args), the
answer is the machine/bsp developer, so we can:

* Add a var like QEMU_SUPPORTED = "yes/no" in the bsp conf file (default to no)
* Add a var like QEMU_BOOT_ARGS = "foo" if there are special args.
* Let do_rootfs or do_image_foo write data such as QEMU_BOOT_ARGS to DEPLOY_DIR_IMAGE/runqemu/ or tmp/deploy/images/runqemu/, we can
treat
the "runqemu/" dir as a database, and anything we need there, for
example,
efi/pcbios, root args, and so on. We won't miss anything since all
the
images which can be boot by runqemu are built by oe-core.
* Then we can easily add supported machine to runqemu from the bsp itself
without change runqemu.

Quoted 3 lines

I will start working on it if there is no objections, and make sure it won't
break any current supported machines.

I guess we have some decisions to make. Firstly, is that script better in shell or python at this point? Originally, shell made sense but I'm starting to wonder if it would be clearer in python.

Quoted 5 lines

If we left it as shell, I'd envisaged it going through something like BBPATH and sourcing files from each of the layers to build up its own list of supported machines. The trouble is we can't easily get BBPATH in the shell environment since we can't assume bitbake and we ideally want it to work outside of our build environment.

Thanks for the reply, my thought is that move part of the implementation into a class called runqemu.bbclass (or other names), and leave the runqemu as a shell script, when QEMU_BOOT_SUPPORTED = "1", runqemu.bbclass will create a:
tmp/deploy/images/<machine>/runqemu

Quoted 8 lines

And the content in runqemu can be: (for example, arm) QEMU="/path/to/sysroots/x86_64-linux/usr/bin/qemu-system-arm -m 128 -machine versatilepb "
TUNE_ARCH="arm"
QEMU_DEFAULT_KERNEL="zImage-qemuarm.bin" QEMU_DEFAULT_FSTYPE="ext4"
QEMU_MEM="-m 128"
[maybe more]

Would it be better to just have a meta-qemu-config-[whateverarch]-native that

publishes the config file? Then it could also publish the config in different forms such as json/yaml/ini for users who don't want to use runqemu, but still

need to know the *required* args. They might want to ignore the rest.

Quoted 21 lines

All of these variables can be defined in bsp layer or conf files. I will add some default values there according to TUNE_ARCH, so that the bsp may not need do anything to boot from qemu when QEMU_BOOT_SUPPORTED = "1".

// Robert

Quoted 15 lines

With the development of devtool, I'm wondering if runqemu should become another such "command", written in python and working in any of the environments we'd expect devtool to work (eSDK, main build). If we did that, we'd have the layers and could easily access BBPATH and search for additional modules to add support for additional machines.

Thoughts?

Cheers,

Richard