Back when the bootloader could only mirror higher half memory linearly
to the lower half, the kernel couldn't be loaded at the beginning of
kernel space because it was unlikely to find enough pages there, so it
was loaded at +1MiB in kernel space. Now the bootloader can map any
pages to the necessary locations, the offset can be removed.
Tags: elf linker virtual memory
Look up the global constructor list that the linker outputs, and run
them all. Required creation of the `kutil::no_construct` template for
objects that are constructed before the global constructors are run.
Also split the `memory_initialize` function into two - one for just
those objects that need to happen before the global ctors, and one
after.
Tags: memory c++
The page table code had been copied mostly verbatim from the kernel, and
was a dense mess. I abstraced the `page_table_indices` class and the old
loop behavior of `map_in` into a new `page_entry_iterator` class, making
both `map_pages` and the initial offset mapping code much cleaner.
Tags: vmem paging
* Link host-targeted binaries with lld
* Add peru script for getting prebuilt sysroot
* Add readme for prebuilt sysroots
* Remove non-working build_sysroot_gcc.sh, rename clang version to just
build_sysroot.sh
More work on process page tables, including only mapping the last 2 pml4
entries (the highest 1TiB of the address space, ie, kernel space) into a
new table.
Includes the work of actually moving the kernel there, which I had
apparently done in name only previously. Oops.
Return to having the bootloader re-map the kernel into the higher
half before jumping into the kernel entrypoint, so we don't have
to juggle pointers inside the kernel.
Kernel image now has a header with version, magic number, and a
pointer to its actual entrypoint. Entry point is now _start in
boot.s, and we now generate versions.s in the build tree for the
version macros.
