Partition Logic 0.76 CD/DVD/FDD/USB

This maintenance release is focused on improved quality, rather than new features. The EXT (Linux) filesystem driver has been re-engineered, the main Partition Logic program has been fixed in numerous ways, and hardware drivers and subsystems such as USB, APIC, and RTC have been tuned.
- Did a fairly major overhaul of the EXT filesystem driver, adding more adaptive feature support, plus support for EXT4 flexible block groups and basic support for EXT4 extent-based files. Also fixed a little bug in the formatting functionality (setting the EXT_INCOMPAT_FILETYPE flag in the superblock).
- Improved the new APIC driver so that it considers the correct priority order when returning the number of the active interrupt. This fixes failures when using the VirtualBox emulator, and some failures seen with the Qemu emulator.
- Partition Logic is slowly transitioning away from the notion of ‘cylinders’, and towards showing the user units of sectors, megabytes, etc.
- Some modern systems don’t allow manual control the A20 address line, but work anyway. The OS loader will still print an error message, but it will no longer terminate booting with a fatal error in such cases.
- Added a extra support for multi-interface (composite) USB devices.
- Improved the EHCI (USB 2.0) driver and the way it manages queue heads and the periodic schedule. Interrupt queue heads for devices are no longer placed directly into the periodic schedule; instead linked, interval-specific queue heads are used. Linked lists of queue head items are now chained correctly.
- All USB device drivers now check to make sure a device hasn’t already been ‘claimed’ by another driver.
- All USB transaction creators now specify timeout values as appropriate, and all of the USB host controller drivers now pay attention to those.
- Added kernel locking to the XHCI (USB 3.0) driver.
- Added a short delay to the XHCI (USB 3.0) controller driver, after setting the port reset bit, before reading it back to check for the ‘clear’. In some cases it can read clear straight away, but the reset hasn’t completed yet, resulting in device detection failures.
- Fine-tuned the PS2 mouse and keyboard timeouts, and the USB keyboard typematic repeat timing.
- Improved the layout code of the window library dialog boxes.
- Got rid of the checks/warnings about disk geometry errors when performing a partition table check. We want to reduce reliance on legacy disk geometry, and frequent mismatches meant a lot of scary-looking warnings that probably didn’t amount to anything anyway.
- The code for specific disk label types (MS-DOS, GPT) now specifies the first and last available sectors for data, and the starting and ending values for new/moved/resized partitions are adjusted to accommodate these.
- Pasting a partition now requires committing changes, as with format operations, erases, filesystem resizes, etc.
- When disks or partitions are erased, it now checks for mounted filesystems, and the kernel is now told to re-scan the filesystem types, the same as after a format operation.
- Now checks for a mounted filesystem before deleting a partition.
- No longer enables the ‘set active’ button/menu item when working with a GPT partition table. The option is meaningless for this disk label type.
- Fixed: The VirtualBox emulator was not cooperating with the RTC driver, and the boot would fail/crash.
- Fixed: A double-fault would occur if an exception was triggered before multitasking was enabled.
- Fixed: ALT-TAB only worked for activating the top menu bar if at least one window existed (i.e. something in the ‘Windows’ menu). It now tries to activate the first menubar menu that has some menu items in it.
- Fixed: Automounting filesystems (from mount.conf) failed if no mount point was set. The filesystems program doesn’t force the user to specify one. The kernel now attempts to use a default (/).
- Fixed: The data moving threads could calculate incorrect sector numbers when copying/moving data from the start of the disk, toward the end of the disk.
- Fixed: Copying and pasting partitions between MS-DOS disks and GPT disks wasn’t working.
- Fixed: An incorrect partition diagram with certain MS-DOS logical partitions. Empty spaces were being calculated using cylinder values, which aren’t necessarily set for logical partitions, by other software.
- Fixed: Pasting a partition into an empty disk would clobber the first track, disk label, etc. of the empty disk.
- Fixed: MS-DOS extended partitions were not having their logical sizes calculated correctly (Parted would complain about ‘overlapping partitions’).
- Fixed: Corrected the numbers shown when querying the user for partition size, when creating or resizing.
- Fixed: The horizontal sliders used for moving, resizing, and creating partitions didn’t update their associated text fields when moved with keyboard presses.
- Fixed: The VSH cursor menu was corrupting memory by attempting to set the text cursor row to a negative number, when there were too many items to fit in the text area/screen. Also added better parameter checking to the kernelText.c code.
- Fixed: a divide-by-zero error in the window library’s windowNumberDialog code, that would cause it to crash when the minimum and maximum values were the same.
- Fixed: 2 bugs related to GUID generation; The structure was not being defined as ‘packed’, and separately, the kernelGuidGenerate() function was over-writing the end of the structure by 2 bytes when writing the node ID.
- Fixed: The file browser program would crash when passed a relative directory name on the command line.