x86[_64]: Separate bootloader and kernel GDT and IDT logic

From now on bootloader sets up its own minimal valid GDT and IDT. Then
the kernel replaces them with its own tables.

x86: Let each CPU have its own GDT

Support for SMP on x86_64.

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.

Made it possible to build the bootloader when targetting x86_64.

* x86_64 is using the existing *_ia32 boot platforms.
* Special flags are required when compiling the loader to get GCC to compile
32-bit code. This adds a new set of rules for compiling boot code rather
than using the kernel rules, which compile using the necessary flags.
* Some x86_64 private headers have been stubbed by #include'ing the x86
versions. These will be replaced later.

* The boot loader does now set up an IDT that allows it to catch processor
exceptions (page faults and the like). The handler dumps possibly interesting
information (registers, a (numerical) stack trace) to the serial output, and,
if possible, also to the screen. That should help debugging boot loader
crashes.
* For the IDT the boot loader sets up for the kernel the descriptors are set up
the same way, so until the kernel initializes the IDT itself (arch_init()) the
facility is still in place and can thus catch very early kernel boot crashes.
Unfortunately the on-screen output doesn't seem to work anymore at that point,
so the output only goes to the serial port...
* ... and to the debug syslog -- dprintf() does now append it there after
debug_cleanup() has been called. Seems to work fine in qemu, but when I tested
it on real hardware the debug syslog was gone.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42092 a95241bf-73f2-0310-859d-f6bbb57e9c96

x86[_64]: Separate bootloader and kernel GDT and IDT logic

From now on bootloader sets up its own minimal valid GDT and IDT. Then
the kernel replaces them with its own tables.

x86: Let each CPU have its own GDT

Support for SMP on x86_64.

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.

Made it possible to build the bootloader when targetting x86_64.

* x86_64 is using the existing *_ia32 boot platforms.
* Special flags are required when compiling the loader to get GCC to compile
32-bit code. This adds a new set of rules for compiling boot code rather
than using the kernel rules, which compile using the necessary flags.
* Some x86_64 private headers have been stubbed by #include'ing the x86
versions. These will be replaced later.

* The boot loader does now set up an IDT that allows it to catch processor
exceptions (page faults and the like). The handler dumps possibly interesting
information (registers, a (numerical) stack trace) to the serial output, and,
if possible, also to the screen. That should help debugging boot loader
crashes.
* For the IDT the boot loader sets up for the kernel the descriptors are set up
the same way, so until the kernel initializes the IDT itself (arch_init()) the
facility is still in place and can thus catch very early kernel boot crashes.
Unfortunately the on-screen output doesn't seem to work anymore at that point,
so the output only goes to the serial port...
* ... and to the debug syslog -- dprintf() does now append it there after
debug_cleanup() has been called. Seems to work fine in qemu, but when I tested
it on real hardware the debug syslog was gone.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42092 a95241bf-73f2-0310-859d-f6bbb57e9c96