We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This utility essentially creates a filesystem sandbox for a specified
command, so it can be tested with only the unveiled paths the user
specifies beforehand.
The Core::System::create_jail function already provided the new jail
index as a result, so it was just a matter of using it when calling the
LibCore join_jail function to use the new jail.
This happens in two ways:
1. LibCore now has two new methods for creating Jails and attaching
processes to a Jail.
2. We introduce 3 new utilities - lsjails, jail-create and jails-attach,
which list jails, create jails and attach processes to a Jail,
respectively.
Let's put the power_state global node into the /sys/kernel directory,
because that directory represents all global nodes and variables being
related to the Kernel. It's also a mutable node, that is more acceptable
being in the mentioned directory due to the fact that all other files in
the /sys/firmware directory are just firmware blobs and are not mutable
at all.
This flag doesn't conform to any POSIX standard nor is found in any OS
out there. The idea behind this mount flag is to ensure that only
non-regular files will be placed in a filesystem, which includes device
nodes, symbolic links, directories, FIFOs and sockets. Currently, the
only valid case for using this mount flag is for TmpFS instances, where
we want to mount a TmpFS but disallow any kind of regular file and only
allow other types of files on the filesystem.
This option, often used with only a lonely dash, allows to "simulate a
login". For now, it just changes the current directory to the home of
the new user.
Before of this patch, we supported two methods to address a boot device:
1. Specifying root=/dev/hdXY, where X is a-z letter which corresponds to
a boot device, and Y as number from 1 to 16, to indicate the partition
number, which can be omitted to instruct the kernel to use a raw device
rather than a partition on a raw device.
2. Specifying root=PARTUUID: with a GUID string of a GUID partition. In
case of existing storage device with GPT partitions, this is most likely
the safest option to ensure booting from persistent storage.
While option 2 is more advanced and reliable, the first option has 2
caveats:
1. The string prefix "/dev/hd" doesn't mean anything beside a convention
on Linux installations, that was taken into use in Serenity. In Serenity
we don't mount DevTmpFS before we mount the boot device on /, so the
kernel doesn't really access /dev anyway, so this convention is only a
big misleading relic that can easily make the user to assume we access
/dev early on boot.
2. This convention although resemble the simple linux convention, is
quite limited in specifying a correct boot device across hardware setup
changes, so option 2 was recommended to ensure the system is always
bootable.
With these caveats in mind, this commit tries to fix the problem with
adding more addressing options as well as to remove the first option
being mentioned above of addressing.
To sum it up, there are 4 addressing options:
1. Hardware relative address - Each instance of StorageController is
assigned with a index number relative to the type of hardware it handles
which makes it possible to address storage devices with a prefix of the
commandset ("ata" for ATA, "nvme" for NVMe, "ramdisk" for Plain memory),
and then the number for the parent controller relative hardware index,
another number LUN target_id, and a third number for LUN disk_id.
2. LUN address - Similar to the previous option, but instead we rely on
the parent controller absolute index for the first number.
3. Block device major and minor numbers - by specifying the major and
minor numbers, the kernel can simply try to get the corresponding block
device and use it as the boot device.
4. GUID string, in the same fashion like before, so the user use the
"PARTUUID:" string prefix and add the GUID of the GPT partition.
For the new address modes 1 and 2, the user can choose to also specify a
partition out of the selected boot device. To do that, the user needs to
append the semicolon character and then add the string "partX" where X
is to be changed for the partition number. We start counting from 0, and
therefore the first partition number is 0 and not 1 in the kernel boot
argument.
