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.
* 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.
* 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.
For now I've just put all the stub functions that are needed to link the
kernel into a file called stubs.cpp. I've not yet moved across the interrupt
handling code or the ELF64 relocation code to the x86 directory. Once those
have been moved I can get rid of the x86_64 headers/source directories.
Not many changes seeing as there's not much x86_64 stuff done yet. Small
differences are handled with ifdefs, large differences (descriptors.h,
struct iframe) have separate headers under arch/x86/32 and arch/x86/64.
The setup procedure is fairly simple: create a 64-bit GDT and 64-bit page
tables that include all kernel mappings from the 32-bit address space, but at
the correct 64-bit address, then go through kernel_args and changes all virtual
addresses to 64-bit addresses, and finally switch to long mode and jump to the
kernel.
Introduce a function to generate the string representation of a bitrate
(kbps, mbps, gbps, etc..)
* Factor out the code from MediaPlayer InfoWindow
* Allow different bases (/1000 or /1024)
* platform_allocate_elf_region() is removed, it is implemented in platform-
independent code now (ELF*Class::AllocateRegion). For ELF64 it is now
assumed that 64-bit addresses are mapped in the loader's 32-bit address space
as (address - KERNEL_BASE_64BIT + KERNEL_BASE).
* mapped_delta field from preloaded_*_image removed, now handled compile-time
using the ELF*Class::Map method.
* Also link the kernel with -z max-page-size=0x1000, removes the need for
2MB alignment on the data segment (not going to map the kernel with large
pages for the time being).
The ELF loader now uses a new platform function, platform_allocate_elf_region,
which returns 2 addresses: the real load address and an address where the
region is mapped in the loader's address space. All of the ELF loading code
has been changed to access the load region through the mapped address rather
than the addresses contained in the ELF image. The ELF64 version of
platform_allocate_elf_region on x86 uses the existing MMU code, which maps
everything at 0x80000000, but returns the correct 64-bit address. The long
mode switch code will just set up the 64-bit address space with everything
remapped at the correct address.
* FixedWidthPointer:
- operators ==/!=: Change second operand type from void* to const
Type*. Also add non-const version to resolve ambiguity warning when
comparing with non-const pointer.
- Add Pointer() getter.
- Remove templatized cast operators. They are nice for casting the
pointer directly to another pointer type, but result in ambiguity.
* Make preloaded_image::debug_string_table non-const. Avoids clashes of
the const and non-coast FixedWidthPointer comparison operators. A
cleaner (but more verbose) solution would be to spezialize
FixedWidthPointer for const types.
The actual implementation of the ELF loading methods have been put into
an ELFLoader template class that takes a single template parameter, which
is a structure containing all the necessary ELF typedefs. It's a bit
verbose, but I thought it was a neater solution than using a bunch of
standalone functions with a huge number of template parameters. There is
no change to code outside of elf.cpp, the ELF32/ELF64 differences are
handled internally.
* There is now 2 structures, preloaded_elf32_image and preloaded_elf64_image,
which both inherit from preloaded_image.
* For now I've just hardcoded in use of preloaded_elf32_image, but the
bootloader ELF code will shortly be converted to use templates which use
the appropriate structure. The kernel will be changed later when I add
ELF64 support to it.
* All kernel_args data is now compatible between 32-bit and 64-bit kernels.
* Added a FixedWidthPointer template class which uses 64-bit storage to hold
a pointer. This is used in place of raw pointers in kernel_args.
* Added __attribute__((packed)) to kernel_args and all structures contained
within it. This is necessary due to different alignment behaviour for
32-bit and 64-bit compilation with GCC.
* With these changes, kernel_args will now come out the same size for both
the x86_64 kernel and the loader, excluding the preloaded_image structure
which has not yet been changed.
* Tested both an x86 GCC2 and GCC4 build, no problems caused by these changes.
I've tested this change on x86, causing no issues. I've checked over the code
for all other platforms and made the necessary changes and to the best of my
knowledge they should also still work, but I haven't actually built and
tested them. Once I've completed the kernel_args changes the other platforms
will need testing.
Pointers in kernel_args are going to be changed to unconditionally use 64-bit
storage (to make kernel_args compatible with both the x86 and x86_64 kernels).
KMessage stores a pointer to its buffer, however since KMessage is used
outside of the boot code it is undesirable to change it to use 64-bit storage
for the pointer as it may add additional overhead on 32-bit builds. Therefore,
only store the buffer address and size and then construct a KMessage from
those in the kernel.
The whole kernel now builds and there are no undefined references when
linking, I just need to fix some strange relocation errors I'm getting
(probably a problem with the linker script) and then I'll have a kernel
image.
Since ICI arguments are used to send addresses in some places, uint32 is
not sufficient on x86_64. addr_t still refers to the same type as uint32
(unsigned long) on other platforms, so this change only really affects
x86_64.
