The bootloader relied on the kernel to know which parts of memory to not
allocate over. For the future shift of having the init process load
other processes instead of the kernel, the bootloader needs a mechanism
to just hand the kernel a list of allocations. This is now done through
the new bootloader allocator, which all allocation goes through. Pool
memory will not be tracked, and so can be overwritten - this means the
args structure and its other structures like programs need to be handled
right away, or copied by the kernel.
- Add bootloader allocator
- Implement a new linked-list based set of pages that act as allocation
registers
- Allow for operator new in the bootloader, which goes through the
global allocator for pool memory
- Split memory map and frame accouting code in the bootloader into
separate memory_map.* files
- Remove many includes that could be replaced by forward declaration in
the bootloader
- Add a new global template type, `counted`, which replaces the
bootloader's `buffer` type, and updated kernel args structure to use it.
- Move bootloader's pointer_manipulation.h to the global include dir
- Make offset_iterator try to return references instead of pointers to
make it more consistent with static array iteration
- Implement a stub atexit() in the bootloader to satisfy clang
The kernel::args namespace is really the protocol for initializing the
kernel from the bootloader. Also, the header struct in that namespace
isn't actually a header, but a collection of parameters. This change
renames the namespace to kernel::init and the struct to args.
The previous frame allocator involved a lot of splitting and merging
linked lists and lost all information about frames while they were
allocated. The new allocator is based on an array of descriptor
structures and a bitmap. Each memory map region of allocatable memory
becomes one or more descriptors, each mapping up to 1GiB of physical
memory. The descriptors implement two levels of a bitmap tree, and have
a pointer into the large contiguous bitmap to track individual pages.
Scanline size can differ from horizontal resolution in some
framebuffers. This isn't currently handled, but at least log it so
it's visible if this lack of handling is a potential error.
After exiting UEFI, the bootloader had no way of displaying status to
the user. Now it will display a series of small boxes as a progress bar
along the bottom of the screen if a framebuffer exists. Errors or
warnings during a step will cause that step's box to turn red or orange,
and display bars above it to signal the error code.
This caused the simplification of the error handling system (which was
mostly just calling status_line::fail) and added different types of
status objects.
If there's no video, do as we did before, otherwise route logs to the fb
driver instead. (Need to clean this up to just have a log consumer
general interface?) Also added a "scrollback" class to fb driver and
updated the system_get_log syscall.
Moved old PSF parsing code from kernel, and switched to embedding whole
PSF instead of just glyph data to make font class the same code paths
for both cases.
Create a new framebuffer driver. Also hackily passing frame buffer size
in the list of init handles to all processes and mapping the framebuffer
into all processes. Changed bootloader passing frame buffer as a module
to its own struct.
