No major changes to the kernel: just compiled in arch_smp.cpp and fixed the
IDT load in arch_cpu_init_percpu to use the correct limit for x86_64 (uses
sizeof(interrupt_descriptor)). In the boot loader, changed smp_boot_other_cpus
to construct a temporary GDT and get the page directory address from CR3, as
what's in kernel_args will be 64-bit stuff and will not work to switch the
CPUs into 32-bit mode in the trampoline code. Refactored 64-bit kernel entry
code to not use the stack after disabling paging, as the secondary CPUs are
given a 32-bit virtual stack address by the SMP trampoline code which will
no longer work.
- The buffer that the debugger used to retrieve messages from
the debug port was slightly too small for the largest of the message
data structs (currently 1100 bytes), causing some types of debug events
to get truncated. This resulted in image creation/deletion events being
received with a truncated image_info struct, which would result in several
fields being returned with random values, most notably the text/data base
and size fields. Consequently, searching those images for an address within
them would fail, leading to #8709. It's possible but not yet confirmed
that this bug is also responsible for #8710, need to test further.
- The version of instantiate_object() that returns the image id from which
the object was reinstantiated was not correctly returning it in all
circumstances, only if it had to find/load the add-on itself. This caused
problems for BShelf since the latter relies on that image id in order to
determine what image to unload when replicants are removed. To remedy this,
introduce an additional version of find_instantiation_func() that returns
the image id in which the instantiation function was found, and make use
of it in instantiate_object() in order to also be able to return the image
id in that case.
* Use gcc and g++ rather than cc and c++, as the latter now point to
clang with recent Xcode versions and compilation of the host tools
fail for various reasons with it.
* Replace the case-sensitive filesystem check with a more basic one,
as diskutil no longer supports the behaviour of getting info for the
volume that any path is on.
* Updated ReadMe with a correct list of prerequisites for OS X.
* GCC 2 builds are still broken due to a strange error that only
occurs with a GCC 2 built on OS X 10.7
Several build features (including a future patch for WebKit)
are enabled only if a respective optional package is added.
Prior to this, none of those build features could be activated
in a sub-jam process.
A proper page fault handler was required for areas that were not locked
into the kernel address space. This enables the boot process to get
up to the point of trying to find the boot volume.
* Thread creation and switching is working fine, however threads do not yet
get interrupted because I've not implemented hardware interrupt handling
yet (I'll do that next).
* I've made some changes to struct iframe: I've removed the e/r prefixes
from the member names for both 32/64, so now they're just named ip, ax,
bp, etc. This makes it easier to write code that works with both 32/64
without having to deal with different iframe member names.
This has been done by adding typedefs in elf_common.h to the correct ELF
structures for the architecture, and changing all Elf32_* uses to those
types. I don't know whether image loading works as I cannot test it yet,
there may be some 64-bit safety issues around. However, symbol lookup for
the kernel is working correctly.
This was an interesting bug to find. Was getting spurious triple faults
in the slab allocator. The problem was that the boot paging setup code
was mapping all page tables it created into the virtual address space,
but in the kernel no areas were being created to cover them, so during
arch_vm_init_end() the pages for them ended up being freed and then
overwritten later on. Fixed by unmapping page tables after populating
them in long_mmu_init().
* mmu_get_virtual_mapping() should check that the page directory entry is
present rather than assuming there's a page table there. This was resulting
in some invalid mappings being created in the 64-bit virtual address space.
* arch_vm_init_end() should clear from KERNEL_LOAD_BASE to virtual_end, not
from KERNEL_BASE. On x86_64 this was causing it to loop through ~512GB of
address space, which obviously was taking quite a while.
* Uses 64-bit multiplication, special handling for CPUs clocked < 1 GHz
in system_time_nsecs() not required like on x86.
* Tested against a straight conversion of the x86 version, noticably
faster with a large number of system_time() calls.
* vm_init now runs up until create_preloaded_image_areas(), which needs
fixing to handle ELF64.
* Not completely tested. I know Map(), Unmap() and Query() work fine, the
other methods have not been tested as the kernel doesn't boot far enough
for any of them to be called yet. As far as I know they're correct, though.
* Not yet implemented the destructor for X86VMTranslationMap64Bit or Init()
for a user address space.
Will be merged with the x86 one later on. Requires -fno-omit-frame-pointer on
the kernel build flags, GCC defaults to not generating stack frames on x86_64.
* Wasn't storing the fixed virtual address of the PML4 in kernel_args.
* After switching to long mode, reload GDTR with the virtual address of
the GDT. This was working fine until now because the physical address
was identity mapped, but broke as soon as I removed the identity
mapping.
* typedef for jmp_buf was using int where it should be long.
* setjmp was clearing the buffer pointer rather than the signal mask before
calling sigsetjmp.
* KDL now works without crashing on x86_64.
Since x86_64 has such a large virtual address space all available physical
memory can be mapped in to it. The physical page mapper implementation for
x86_64 will use this mapping. Also changed the mapping code to map kernel
pages with the global flag.
* Added empty source files for all the 64-bit paging method code, and a
stub implementation of X86PagingMethod64Bit.
* arch_vm_translation_map.cpp has been modified to use X86PagingMethod64Bit
on x86_64.
* Some things are currently ifndef'd out completely for x86_64 because
they aren't implemented, there's a few other ifdef's to handle x86_64
differences but most of the code works unchanged.
* Renamed some i386_* functions to x86_*.
* Added a temporary method for setting the current thread on x86_64
(a global variable, not SMP safe). This will be changed to be done
via the GS segment but I've not implemented that yet.
Since the button was renamed from "Do it!" to the specific action,
an additional explanation in case of special user folders isn't
needed any more.
Split text into paragraphs for better readability.
