Prototyping shorthands

[edubart]

Some people are beginning to use cartesi-machine to prototype and test new software directly. This PR adds new shorthands to make easier to use common prototyping commands:

• -m shorthand for --ram-length
• -k shorthand for --ram-image
• -q shorthand for --quiet --no-init-splash
• -r/--rootfs shorthand for --flash-drive=label:root,filename:<filename>
• -S/--shared-rootfs shorthand for setting rootfs as shared

Use case example

This PR goal is to make the following prototyping use case less boilerplate (smaller commands).

Suppose I installed latest cartesi machine on my system, and I would like to try out new software just to check if it the machine would run it (I don't want to mess with Docker yet! I am not really creating a dapp neither! just a quick test!).

First thing I would do is to copy standard rootfs.ext2 and resize it to be bigger, and I can use resize2fs inside cartesi machine to do this:

$ cp $(cartesi-machine --version-json | jq -r .default_rootfs_image) rootfs.ext2
$ cartesi-machine -q -v=.:/mnt -u=root -- resize2fs -f /mnt/rootfs.ext2 512M

Now I would like to install new software in this custom rootfs, like gcc, I also want the changes to persist:

$ cartesi-machine -q -n -S -r=rootfs.ext2 -u=root -- "apt-get update && apt-get install -y gcc"

Finally I could share host current directory and start compiling GCC and testing programs inside the cartesi machine:

$ echo "int main(){}" > test.c
$ cartesi-machine -q -m=256Mi -v=.:/mnt -w=/mnt -r=rootfs.ext2 -u=root -h=playground -it bash
root@playground:/mnt# gcc test.c -o test && ./test
root@playground:/mnt# 

Lastly I could even make this my rootfs with GCC the default on my machine, with:

$ cp $(cartesi-machine --version-json | jq -r .default_ram_image) linux.bin
$ export CARTESI_IMAGES_PATH=`pwd`
$ cartesi-machine -q -- gcc --version
gcc (Ubuntu 13.2.0-23ubuntu4) 13.2.0