The x86 paging code has been rewritten to support another paging mode
and non-identity virtual mappings.
- Paging code now uses an array of paging level characteristics and
walks tables using for loops. This is opposed to having different
functions for every paging level and lots of #ifdefs. The code is
now more concise and adding new paging modes should be trivial.
- We now support 32-bit, PAE, and IA-32e page tables.
- The page tables created by gen_mmu.py are now installed at early
boot. There are no longer separate "flat" page tables. These tables
are mutable at any time.
- The x86_mmu code now has a private header. Many definitions that did
not need to be in public scope have been moved out of mmustructs.h
and either placed in the C file or in the private header.
- Improvements to dumping page table information, with the physical
mapping and flags all shown
- arch_mem_map() implemented
- x86 userspace/memory domain code ported to use the new
infrastructure.
- add logic for physical -> virtual instruction pointer transition,
including cleaning up identity mappings after this takes place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This had been copy-pasted between linker scripts, create
a central header for it.
The linker scripts for xtensa and posix have very different
structure and have been left alone.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Previously, DTS specification of physical RAM bounds did not
correspond to the actual bounds of system RAM as the first
megabyte was being skipped.
There were reasons for this - the first 1MB on PC-like systems
is a no-man's-land of reserved memory regions, but we need DTS
to accurately capture physical memory bounds.
Instead, we introduce a config option which can apply an offset
to the beginning of physical memory, and apply this to the "RAM"
region defined in the linker scripts.
This also fixes a problem where an extra megabyte was being
added to the size of system RAM.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Remove Kconfig, linker script, and related bits associated with
CUSTOM_RODATA_LD, CUSTOM_RWDATA_LD, CUSTOM_SECTIONS_LD,
SOC_NOINIT_LD, SOC_RODATA_LD, and SOC_RWDATA_LD options that have been
deprecated since Zephyr 2.2.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Rework x86 linker scripts to use DT_REG_ADDR/DT_REG_SIZE on
DT_CHOSEN(zephyr_sram) and DT_CHOSEN(zephyr_flash). As part of this
we remove the dts_fixup.h. Using DT_REG_SIZE means we don't have to
adjust the sizes by 1024.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This operation is formally defined as rounding down a potential
stack pointer value to meet CPU and ABI requirments.
This was previously defined ad-hoc as STACK_ROUND_DOWN().
A new architecture constant ARCH_STACK_PTR_ALIGN is added.
Z_STACK_PTR_ALIGN() is defined in terms of it. This used to
be inconsistently specified as STACK_ALIGN or STACK_PTR_ALIGN;
in the latter case, STACK_ALIGN meant something else, typically
a required alignment for the base of a stack buffer.
STACK_ROUND_UP() only used in practice by Risc-V, delete
elsewhere.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The callee-saved registers have been separated out and will not
be saved/restored if exception debugging is shut off.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Implement a set of per-cpu trampoline stacks which all
interrupts and exceptions will initially land on, and also
as an intermediate stack for privilege changes as we need
some stack space to swap page tables.
Set up the special trampoline page which contains all the
trampoline stacks, TSS, and GDT. This page needs to be
present in the user page tables or interrupts don't work.
CPU exceptions, with KPTI turned on, are treated as interrupts
and not traps so that we have IRQs locked on exception entry.
Add some additional macros for defining IDT entries.
Add special handling of locore text/rodata sections when
creating user mode page tables on x86-64.
Restore qemu_x86_64 to use KPTI, and remove restrictions on
enabling user mode on x86-64.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
- In early boot, enable the syscall instruction and set up
necessary MSRs
- Add a hook to update page tables on context switch
- Properly initialize thread based on whether it will
start in user or supervisor mode
- Add landing function for system calls to execute the
desired handler
- Implement arch_user_string_nlen()
- Implement logic for dropping a thread down to user mode
- Reserve per-CPU storage space for user and privilege
elevation stack pointers, necessary for handling syscalls
when no free registers are available
- Proper handling of gs register considerations when
transitioning privilege levels
Kernel page table isolation (KPTI) is not yet implemented.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We use a fixed value of 32 as the way interrupts/exceptions
are setup in x86_64's locore.S do not lend themselves to
Kconfig configuration of the vector to use.
HW-based kernel oops is now permanently on, there's no reason
to make it optional that I can see.
Default vectors for IPI and irq offload adjusted to not
collide.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Nothing too fancy here, we try as much as possible to
use the same register layout as the C calling convention.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Includes linker script fragments for the kernel object
tables and automatic memory partitions. The data section
is moved to the end per the requirements of
include/linker/kobject.h.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We don't need to set up GDT data descriptors for setting
%gs. Instead, we use the x86 MSRs to set GS_BASE and
KERNEL_GS_BASE.
We don't currently allow user mode to set %gs on its own,
but later on if we do, we have everything set up to issue
'swapgs' instructions on syscall or IRQ.
Unused entries in the GDT have been removed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
These were previously assumed to always be fatal.
We can't have the faulting thread's XMM registers
clobbered, so put the SIMD/FPU state onto the stack
as well. This is fairly large (512 bytes) and the
execption stack is already uncomfortably small, so
increase to 2K.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.
This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit refactors kernel and arch headers to establish a boundary
between private and public interface headers.
The refactoring strategy used in this commit is detailed in the issue
This commit introduces the following major changes:
1. Establish a clear boundary between private and public headers by
removing "kernel/include" and "arch/*/include" from the global
include paths. Ideally, only kernel/ and arch/*/ source files should
reference the headers in these directories. If these headers must be
used by a component, these include paths shall be manually added to
the CMakeLists.txt file of the component. This is intended to
discourage applications from including private kernel and arch
headers either knowingly and unknowingly.
- kernel/include/ (PRIVATE)
This directory contains the private headers that provide private
kernel definitions which should not be visible outside the kernel
and arch source code. All public kernel definitions must be added
to an appropriate header located under include/.
- arch/*/include/ (PRIVATE)
This directory contains the private headers that provide private
architecture-specific definitions which should not be visible
outside the arch and kernel source code. All public architecture-
specific definitions must be added to an appropriate header located
under include/arch/*/.
- include/ AND include/sys/ (PUBLIC)
This directory contains the public headers that provide public
kernel definitions which can be referenced by both kernel and
application code.
- include/arch/*/ (PUBLIC)
This directory contains the public headers that provide public
architecture-specific definitions which can be referenced by both
kernel and application code.
2. Split arch_interface.h into "kernel-to-arch interface" and "public
arch interface" divisions.
- kernel/include/kernel_arch_interface.h
* provides private "kernel-to-arch interface" definition.
* includes arch/*/include/kernel_arch_func.h to ensure that the
interface function implementations are always available.
* includes sys/arch_interface.h so that public arch interface
definitions are automatically included when including this file.
- arch/*/include/kernel_arch_func.h
* provides architecture-specific "kernel-to-arch interface"
implementation.
* only the functions that will be used in kernel and arch source
files are defined here.
- include/sys/arch_interface.h
* provides "public arch interface" definition.
* includes include/arch/arch_inlines.h to ensure that the
architecture-specific public inline interface function
implementations are always available.
- include/arch/arch_inlines.h
* includes architecture-specific arch_inlines.h in
include/arch/*/arch_inline.h.
- include/arch/*/arch_inline.h
* provides architecture-specific "public arch interface" inline
function implementation.
* supersedes include/sys/arch_inline.h.
3. Refactor kernel and the existing architecture implementations.
- Remove circular dependency of kernel and arch headers. The
following general rules should be observed:
* Never include any private headers from public headers
* Never include kernel_internal.h in kernel_arch_data.h
* Always include kernel_arch_data.h from kernel_arch_func.h
* Never include kernel.h from kernel_struct.h either directly or
indirectly. Only add the kernel structures that must be referenced
from public arch headers in this file.
- Relocate syscall_handler.h to include/ so it can be used in the
public code. This is necessary because many user-mode public codes
reference the functions defined in this header.
- Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is
necessary to provide architecture-specific thread definition for
'struct k_thread' in kernel.h.
- Remove any private header dependencies from public headers using
the following methods:
* If dependency is not required, simply omit
* If dependency is required,
- Relocate a portion of the required dependencies from the
private header to an appropriate public header OR
- Relocate the required private header to make it public.
This commit supersedes #20047, addresses #19666, and fixes#3056.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
Move _LINKER and _ASMLANGUAGE to target.cmake because of how we pick the
linker script that might be used. This way regardless of how or where a
linker.ld gets included we will always set _LINKER & _ASMLANGUAGE (so
any header that needs check based on those defines they can,
specifically generated_dts_board.h)
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Same snippet as in our 32-bit linker file. Creates
an iterable section with all the MMU_BOOT_REGION() info.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Some linker symbols indicating the bounds of various memory
areas needed for setting up boot MMU regions are now in
place.
MMU_BOOT_REGION macros added to align the bounds of these
sections if we're using runtime page tables.
_image_rodata_start moved to the proper place, it was not
accounting for the rodata sections specified in
linker/common_rom.ld.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Program text, rodata, and data need different MMU
permissions. Split out rodata and data from the program
text, updating the linker script appropriately.
Region size symbols added to the linker script, so these
can later be used with MMU_BOOT_REGION().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is really just to facilitate CPU bootstrap code between
the BSP and the APs, moving the clear operation out of the way.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
The linker script was missing symbols that defined the boundaries
of kernel memory segments (_image_rom_end, etc.). These are added
so that core/memmap.c can properly account for those segments.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Declare the 64-bit TSS as a struct, and define the instance in C.
Add a data segment selector that overlaps the TSS and keep that
loaded in GS so we can access the TSS via a segment-override prefix.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
This is largely a conceptual change rather than an actual change.
Instead of using an array of interrupt stacks (one for each IRQ
nesting level), we use one interrupt stack and subdivide it. The
effect is the same, but this is more in line with the Zephyr model
of one ISR stack per CPU (as reflected in init.c).
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Include .gcc_except_table (sub-)sections in linker files to support C++
with exceptions enabled. If these sections are not mapped warnings will
be generated for orphaned sections at link time.
Signed-off-by: Jan Van Winkel <jan.van_winkel@dxplore.eu>
Not sure why these were formatted the way they were, but I've removed
unnecessary line breaks, embedded control characters (actual embedded
tabs, not escape sequences) and escape sequences.
No functional change.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
The previous linker script was barebones and non-standard. It is
replaced with a script conforms to the rest of the Zephyr arches,
utilizing include/linker headers and standard macros.
link-tool-gcc.h is updated to account for the "i386:x86-64" arch and
the generation of 64-bit ELF binaries.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Fleshed out z_arch_esf_t and added code to build this frame when
exceptions occur. Created a separate small stack for exceptions and
shifted the initialization code to use this instead of the IRQ stack.
Moved IRQ stack(s) to irq.c.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
First "complete" version of Intel64 support for x86. Compilation of
apps for supported boards (read: up_squared) with CONFIG_X86_LONGMODE=y
is now working. Booting, device drivers, interrupts, scheduling, etc.
appear to be functioning properly. Beware that this is ALHPA quality,
not ready for production use, but the port has advanced far enough that
it's time to start working through the test suite and samples, fleshing
out any missing features, and squashing bugs.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Simplified these two inline functions somewhat, and refactored them:
unlocking can be shared between subarches, but locking cannot.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
The sys_inXX() and sys_read/writeXX() I/O primitives can be shared
between subarches of x86 with minor modifications, so move them.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
This patch adds basic build infrastructure, definitions, a linker
script, etc. to use the Zephyr and 0.10.1 SDK to build a 64-bit
ELF binary suitable for use with GRUB to minimally bootstrap an
Apollo Lake (e.g., UpSquared) board. The resulting binary can hardly
be called a Zephyr kernel as it is lacking most of the glue logic,
but it is a starting point to flesh those out in the x86 tree.
The "kernel" builds with a few harmless warnings, both with GCC from
the Zephyr SDK and with ICC (which is currently being worked on in
a separate branch). These warnings are either related to pointer size
differences (since this is an LP64 build) and/or dummy functions
that will be replaced with working versions shortly.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Some of the elements of arch.h can be shared between subarches,
so put them in a common file and factor out the rest. Placeholder
left for the Intel64 definitions to be added later.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
