This command line flag can be used to disable VirtIO support on
certain configurations (native windows) where interfacing with
virtio devices can cause qemu to freeze.
Helps with bare metal debugging, as we can't be sure our implementation
will work with a given machine.
As reported by someone on Discord, their machine hangs when we attempt
the dummy transfer.
The first one is for disabling the PS2 controller, the other one is for
disabling physical storage enumeration.
We can't be sure any machine will work with our implementation,
therefore this will help us to test more machines.
Now the kernel supports 2 ECAM access methods.
MMIOAccess was renamed to WindowedMMIOAccess and is what we had until
now - each device that is detected on boot is assigned to a
memory-mapped window, so IO operations on multiple devices can occur
simultaneously due to creating multiple virtual mappings, hence the name
is a memory-mapped window.
This commit adds a new class called MMIOAccess (not to be confused with
the old MMIOAccess class). This class creates one memory-mapped window.
On each IO operation on a configuration space of a device, it maps the
requested PCI bus region to that window. Therefore it holds a SpinLock
during the operation to ensure that no other PCI bus region was mapped
during the call.
A user can choose to either use PCI ECAM with memory-mapped window
for each device, or for an entire bus. By default, the kernel prefers to
map the entire PCI bus region.
Apparently we don't enable PCI ECAM (MMIO access to the PCI
configuration space) even if we can. This is a regression, as it was
enabled in the past and in unknown time it was regressed.
The CommandLine::is_mmio_enabled method was renamed to
CommandLine::is_pci_ecam_enabled to better represent the meaning
of this method and what it determines.
Also, an UNMAP_AFTER_INIT macro was removed from a method
in the MMIOAccess class as it halted the system when the kernel
tried to access devices after the boot process.
This reverts commit cfc2f33dcb.
We can't actually change the IRQ line value and expect the device
to work with it (this was my mistake).
That register is R/W so the firmware can figure out IRQ routing and put
the correct value and write it to the Interrupt line register.
As a compromise, if the fimrware decided to set the IRQ line to be 7,
or something else we can't deal with, the user can simply force the code
to work with IRQ 11, with the boot argument "force_ahci_irq_11" being
set to "on".
Instead of blindly resetting every AHCI port, let's just reset only the
controller by default. The user can still request to reset everything
with a new kernel boot argument called ahci_reset_mode which is set
by default to "controller", so the code will only invoke an HBA reset.
This kernel boot argument can be set to 3 different values:
1. "controller" - reset the HBA and skip resetting AHCI ports
2. "none" - don't reset anything, so we rely on the firmware to
initialize the AHCI HBA and ports for us.
3. "complete" - reset the AHCI HBA and ports.
The full system profiling functionality is useful for profiling the
boot performance of the system. Add a new kernel boot option to start
the system with profiling enabled. This lets you disable and view a
profile once the system is booted.
You can use it by running:
```
$ run.sh qcmd boot_prof
```
Previously all of the CommandLine parsing was spread out around the
Kernel. Instead move it all into the Kernel CommandLine class, and
expose a strongly typed API for querying the state of options.
- If there is no VMWare backdoor, don't allocate memory for it.
- Remove the "unsupported" state, instead just don't instantiate.
- Move the command-line parsing from init to the driver.
- Move mouse packet reception from PS2MouseDevice to VMWareBackdoor.
