The moving of kernel-only code out of kutil continues. (See 042f061)
This commit moves the following:
- The heap allocator code
- memory.cpp/h which means:
- letting string.h be the right header for memset and memcpy, still
including an implementation of it for the kernel though, since
we're not linking libc to the kernel
- Changing calls to kalloc/kfree to new/delete in kutil containers
that aren't going to be merged into the kernel
- Fixing a problem with stdalign.h from libc, which was causing issues
for type_traits.
Part two of rearranging kutil code. (See 042f061) Removing unused kutil
headers:
I can imagine that avl_tree or slab_allocated may want to be returned to
at some point, but for now they're just clutter.
Part one of a series of code moves. The kutil library is not very
useful, as most of its code is kernel-specific. This was originally for
testing purposes, but that can be achieved in other ways with the
current build system. I find this mostly creates a strange division in
the kernel code.
Instead, I'm going to move everything kernel-specific to actually be in
the kernel, and replace kutil with just 'util' for generic utility code
I want to share.
This commit:
- Moves the logger into the kernel.
- Updates the 'printf' library used from mpaland/printf to
eyalroz/printf and moved it into the kernel, as it's only used by the
logger in kutil.
- Removes some other unused kutil headers from some files, to help
future code rearrangement.
Note that the (now redundant-seeming) log.cpp/h in kernel is currently
still there - these files are more about log output than the logging
system, and will get replaced once I add user-space log output.
Fixing two page allocation issues I came across while debugging:
- Added a spinlock to the page_table static page cache, to avoid
multiple CPUs grabbing the same page. This cache should probably
just be made into per-CPU caches.
- Fixed a bitwise math issue ("1" instead of "1ull" when working with
64-bit numbers) that made it so that pages were never marked as
allocated when allocating 32 or more.
Updated kassert to be an actual function, and used the __builtin_*
functions for location data. Updated the panic handler protocol to
include sending location data as three more parameters. Updated the
serial panic handler to display that data along with the (optional)
message.
Add a simple ELF loader to srv.init to load and start any module_program
parameters passed from the bootloader. Also creates stacks for newly
created threads.
Also update thread creation in testapp to create stacks.
Stop creating stacks in user space for user threads, that should be done
by the thread's creator. This change adds process and stack_top
arguments to the thread_create syscall, so that threads can be created
in other processes, and given a stack address.
Also included is a fix in add_thunk_user due to the r11/flags change.
THIS COMMIT BREAKS USERSPACE. See subsequent commits for the user side
changes related to this change.
The vm_area objects had a number of issues I have been running into when
working on srv.init:
- It was impossible to map a VMA, fill it, unmap it, and hand it to
another process. Unmapping the VMA in this process would cause all the
pages to be freed, since it was removed from its last mapping.
- If a VMA was marked with vm_flag::zero, it would be zeroed out _every
time_ it was mapped into a vm_space.
- The vm_area_open class was leaking its page_tree nodes.
In order to fix these issues, the different VMA types all work slightly
differently now:
- Physical pages allocated for a VMA are now freed when the VMA is
deleted, not when it is unmapped.
- A knock-on effect from the first point is that vm_area_guarded is now
based on vm_area_open, instead of vm_area_untracked. An untracked area
cannot free its pages, since it does not track them.
- The vm_area_open type now deletes its root page_tree node. And
page_tree nodes will delete child nodes or free physical pages in
their dtors.
- vm_flag::zero has been removed; pages will need to be zeroed out
further at a higher level.
- vm_area also no longer deletes itself only on losing its last handle -
it will only self-delete when all handles _and_ mappings are gone.
The page_tree struct was doing a lot of bit manipulation to keep its
base, level, and flags in a single uint64_t. But since this is such a
large structure anyway, another word doesn't change it much and greatly
simplifies both the code and reasoning about it.
This change adds a new interface DSL for specifying objects (with
methods) and interfaces (that expose objects, and optionally have their
own methods).
Significant changes:
- Add the new scripts/definitions Python module to parse the DSL
- Add the new definitions directory containing DSL definition files
- Use cog to generate syscall-related code in kernel and libj6
- Unify ordering of pointer + length pairs in interfaces
This change moves Bonnibel from a separate project into the jsix tree,
and alters the project configuration to be jsix-specific. (I stopped
using bonnibel for any other projects, so it's far easier to make it a
custom generator for jsix.) The build system now also uses actual python
code in `*.module` files to configure modules instead of TOML files.
Target configs (boot, kernel-mode, user-mode) now moved to separate TOML
files under `configs/` and can inherit from one another.
I'm a tabs guy. I like tabs, it's an elegant way to represent
indentation instead of brute-forcing it. But I have to admit that the
world seems to be going towards spaces, and tooling tends not to play
nice with tabs. So here we go, changing the whole repo to spaces since
I'm getting tired of all the inconsistent formatting.
I was seeing more ignored interrupts when debugging, trying to shorten
their path more. Adding a separate ISR for ignored interrupts was the
shortest path, but that caused some strange instability that I'm not in
the mood to track down.
Created the framework for using different loadable panic handlers,
loaded by the bootloader. Initial panic handler is panic.serial, which
contains its own serial driver and stacktrace code.
Other related changes:
- Asserts are now based on the NMI handler - panic handlers get
installed as the NMI interrupt handler
- Changed symbol table generation: now use nm's own demangling and
sorting, and include symbol size in the table
- Move the linker script argument out of the kernel target, and into the
kernel's specific module, so that other programs (ie, panic handlers)
can use the kernel target as well
- Some asm changes to boot.s to help GDB see stack frames - but this
might not actually be all that useful
- Renamed user_rsp to just rsp in cpu_state - everything in there is
describing the 'user' state
Resurrect the existing but unused ELF library in libraries/elf, and use
it instead of boot/elf.h for parsing ELF files in the bootloader.
Also adds a const version of offset_iterator called
const_offset_iterator.
Pull this widely-useful header out of kutil, so more things can use it.
Also replace its dependency on <type_traits> by defining our own custom
basic_types.h which contains a subset of the standard's types.
Create a new usermode program, srv.init, and have it read the initial
module_page args sent to it by the bootloader. Doesn't yet do anything
useful but sets up the way for loading the rest of the programs from
srv.init.
Other (mostly) related changes:
- bootloader: The allocator now has a function for allocating init
modules out of a modules_page slab. Also changed how the allocator is
initialized and passes the allocation register and modules_page list
to efi_main().
- bootloader: Expose the simple wstrlen() to the rest of the program
- bootloader: Move check_cpu_supported() to hardware.cpp
- bootloader: Moved program_desc to loader.h and made the loader
functions take it as an argument instead of paths.
- kernel: Rename the system_map_mmio syscall to system_map_phys, and
stop having it default those VMAs to having the vm_flags::mmio flag.
Added a new flag mask, vm_flags::driver_mask, so that drivers can be
allowed to ask for the MMIO flag.
- kernel: Rename load_simple_process() to load_init_server() and got rid
of all the stack setup routines in memory_bootstrap.cpp and task.s
- Fixed formatting in config/debug.toml, undefined __linux and other
linux-specific defines, and got rid of _LIBCPP_HAS_THREAD_API_EXTERNAL
because that's just not true.
Separate the video mode setting out from the console code into video.*,
and remove the framebuffer from the kernel args, moving it to the new
init args format.
A long overdue cleanup of the src/ tree.
- Moved src/drivers to src/user because it contains more than drivers
- Removed src/drivers/ahci because it's unused - will restore it when I
make a real AHCI driver
- Removed unused src/tools
- Moved kernel.ld (the only used file under src/arch) to src/kernel for
now, if/when there's a multi-platform effort that should be figured
out as part of it
- Removed the rest of the unused src/arch
- Renamed 'fb' to 'drv.uefi_fb' and 'nulldrv' to 'testapp'
The bootloader's load_program was reproducing all loadable program
header sections into new pages. Now only do that for sections containing
BSS sections (eg, where file size and mem size do not match).
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 scheduler queue locks could deadlock if the timer fired before the
scoped lock destructor ran. Also, reduce lock contention by letting only
one CPU steal work at a time.
Spinlock release uses __atomic_compare_exchange_n, which overwrites the
`desired` parameter with the actual value when the compare fails. This
was causing releases to always spin when there was lock contention.
Add the object_wait_many syscall to allow programs to wait for signals
on multiple objects at once. Also removed the object argument to
thread::wait_on_signals, which does nothing with it. That information is
saved in the thread being in the object's blocked threads list.
The kernel's file header has not been verified for a long time. This
change returns file verification to the bootloader to make sure the ELF
loaded in position 0 is actually the kernel.
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.
Update the cpu data to point to the fake kernel process in
cpu_early_init so there can never be a race condition where the current
process may not be set.
The idle threads for the APs have intentionally tiny stacks. Logging is
currently an absolute hog of stack space, so avoid logging on the idle
stacks as much as possible.
Eventually we should instead just reclaim the physical pages used by
most of the stack instead of making them tiny.
