There is no need to use this kconfig, as the phys-to-virt
offset is enough to figure out if the kernel is linked in
virtual address space in gen_mmu.py.
For code, use Z_VM_KERNEL instead.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
With the introduction of Z_MEM_*_ADDR for physical<->virtual
address translation, there is no need to have x86 specific
versions.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
For some unknown reason, the pagetable address for _df_tss.cr3
did not get translated from virtual to physical. However,
the translation is done if the pointer to pagetable is obtained
through reference to the first array element (instead of simply
through the name of array). Without CR3 pointing to the page
table via physical address, double fault does not work. So
fixing this by being explicit with the page table pointer.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
When adding a new thread to memory domain, there is a NULL check
to figure out if a thread is being migrated to another memory
domain. However, the NULL check is AFTER physical-to-virtual
address translation which means (NULL + offset) != NULL anymore.
This results in calling reset_region() with an invalid page table
pointer. Fix this by doing the NULL check before address
translation.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
When linking in virtual address space, we still need physical
addresses in SRAM to be mapped so platform can boot from physical
memory and to access structure necessary for boot (e.g. GDT and
IDT). So we need to enlarge the reserved space for page table
to accommodate this.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
We have been having the assumption that the physical memory
is identity-mapped to virtual address space. However, with
the ability to set CONFIG_KERNEL_VM_BASE separately from
CONFIG_SRAM_BASE_ADDRESS, the assumption is no longer valid.
This changes the boot code in x86 32-bit, so that once
the page table is loaded, we can proceed with executing in
the virtual address space. So do a long jump to virtual
address just before calling z_x86_prep_c. From this point on,
code execution is in virtual address space.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds virtual address translation to a few variables
used in crt0.S. This is needed as they are linked at
virtual addresses but before page table is loaded,
they are not available at virtual addresses and must be
referred via physical addresses.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
When feeding &z_shared_kernel_page_start directly to
Z_X86_PHYS_ADDR(), the compiler would complain array subscript
out of bound if linking in virtual address space. So cast it
into uintptr_t first before translation.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Add a newer, much smaller and simpler implementation of abort and
join. No need to involve the idle thread. No need for a special code
path for self-abort. Joining a thread and waiting for an aborting one
to terminate elsewhere share an implementation. All work in both
calls happens under a single locked path with no unexpected
synchronization points.
This fixes a bug with the current implementation where the action of
z_sched_single_abort() was nonatomic, releasing the lock internally at
a point where the thread to be aborted could self-abort and confuse
the state such that it failed to abort at all.
Note that the arm32 and native_posix architectures, which have their
own thread abort implementations, now see a much simplified
"z_thread_abort()" internal API.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Instead of doing these in assembly, use the common z_bss_zero()
and z_data_copy() C functions instead. This simplifies code
a bit and we won't miss any additions to these two functions
(if any) under x86 in the future (as x86_64 was actually not
clearing gcov bss area).
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This moves calling z_loapic_enable() from crt0.S into
z_x86_prep_c(). This is done so we can move BSS clearing
and data section copying inside z_x86_prep_c() as
these are needed before calling z_loapic_enable().
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds a new kconfig to enable the use of memory map.
This map can be populated automatically if
CONFIG_MULTIBOOT_MEMMAP=y or can be manually defined
via x86_memmap[].
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is an hidden option to indicate we are building for
PC-compatible devices (where there are BIOS, ACPI, etc.
which are standard on such devices).
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Before accessing the multiboot data passed by the bootloader,
we need to map the memory first. This adds the code to map
the memory if necessary.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
We assume that all x86 CPUs do have clflush instructions.
And the cache line size is now provided through DTS.
So detecting clflush instruction as well as the cache line size is no
longer required at runtime and thus removed.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
This adds X86 keyword to the kconfigs to indicate these are
for x86. The old options are still there marked as
deprecated.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
With x86, there are usually memory regions that are reserved
for firmware and device MMIOs. We don't want to use these
pages for memory mapping so mark them as reserved at boot.
The weakly defined x86_memmap contains the list of memory
regions which can be overriden by SoC or board configurations.
Also, with CONFIG_MULTIBOOT_MEMMAP=y, the memory regions
are populated from multiboot provided data.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The x86_64 SysV ABI requires 16 byte alignment for the stack pointer
during execution of normal code. That means that on entry to an
ABI-compatible C function (which is reached via a CALL instruction
that pushes the return address) the RSP register must be MISaligned by
exactly 8 bytes. The kernel mode thread setup got this right, but we
missed the equivalent condition in userspace entry.
The end result was a misaligned stack, which is surprisingly robust
for most use. But recent toolchains have starting doing some more
elaborate vectorization, and the resulting SSE instructions started
failing in userspace on the misaliged loads.
Note that there's a comment about optimization: we're doing the stack
alignment in the "wrong place" and are needlessly wasting bytes in
some cases. We should see the raw stack boundaries where we are
setting up RSP values. Add a FIXME to this effect, but don't touch
anything as this patch is a targeted bugfix.
Also fix a somewhat embarassing 32-bit-ism that would have truncated
the address of a userspace stack that we tried to put above 4G.
Fixes#31018
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
On Intel processors, if GS is not zero and is being set to
zero, GS_BASE is also being set to zero. This would interfere
with the actual use of GS_BASE for usespace. To avoid accidentally
clearing GS_BASE, simply set GS to 0 at boot, so any subsequent
clearing of GS will not clear GS_BASE.
The clearing of GS_BASE was discovered while trying to figure out
why the mem_protect test would hang within 10-20 repeated runs.
GDB revealed that both GS and GS_BASE was set to zero when the tests
hanged. After setting GS to zero at boot, the mem_protect tests
were running repeated for 5,000+ times without hanging.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
All arch_ APIs and macros are implemented, and the page fault
handling code will call into the core kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Pre-allocation of paging structures is now required, such that
no allocations are ever needed when mapping memory.
Instantiation of new memory domains may still require allocations
unless a common page table is used.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We no longer use a page pool to draw memory pages when doing
memory map operations. We now preallocate the entire virtual
address space so no allocations are ever necessary when mapping
memory.
We still need memory to clone page tables, but this is now
expressed by a new Kconfig X86_MAX_ADDITIONAL_MEM_DOMAINS
which has much clearer semantics than specifying the number
of pages in the pool.
The default address space size is now 8MB, but this can be
tuned by the application.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
A more comprehensive solution would use E820 enumeration, but we
are unlikely to ever care that much, as we intend to use demand
paging on microcontrollers and not PC-like hardware. This is
really to just prevent QEMU from crashing.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This removes the z_ prefix those (functions, enums, etc.) that
are being used outside the coredump subsys. This aligns better
with the naming convention.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
All arch_ APIs and macros are implemented, and the page fault
handling code will call into the core kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Pre-allocation of paging structures is now required, such that
no allocations are ever needed when mapping memory.
Instantiation of new memory domains may still require allocations
unless a common page table is used.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We no longer use a page pool to draw memory pages when doing
memory map operations. We now preallocate the entire virtual
address space so no allocations are ever necessary when mapping
memory.
We still need memory to clone page tables, but this is now
expressed by a new Kconfig X86_MAX_ADDITIONAL_MEM_DOMAINS
which has much clearer semantics than specifying the number
of pages in the pool.
The default address space size is now 8MB, but this can be
tuned by the application.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
A more comprehensive solution would use E820 enumeration, but we
are unlikely to ever care that much, as we intend to use demand
paging on microcontrollers and not PC-like hardware. This is
really to just prevent QEMU from crashing.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This adds the correct compiler and linker flags to
support software floating point operations. The flags
need to be added to TOOLCHAIN_*_FLAGS for GCC to find
the correct library (when calling GCC with
--print-libgcc-file-name).
Note that software floating point needs to be turned
on for Newlib. This is due to Newlib having floating
point numbers in its various printf() functions which
results in floating point instructions being emitted
from toolchain. These instructions are placed very
early in the functions which results in them being
executed even though the format string contains
no floating point conversions. Without using CONFIG_FPU
to enable hardware floating point support, any calls to
printf() like functions will result in exceptions
complaining FPU is not available. Although forcing
CONFIG_FPU=y with newlib is an option, and because
the OS doesn't know which threads would call these
printf() functions, Zephyr has to assume all threads
are using FPU and thus incurring performance penalty as
every context switching now needs to save FPU registers.
A compromise here is to use soft float instead. Newlib
with soft float enabled does not have floating point
instructions and yet can still support its printf()
like functions.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The new APIs are not only dealing with cache flushing. Rename the
Kconfig symbol to CACHE_MANAGEMENT to better reflect this change.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
The kconfig options to configure the cache flushing framework are
currently living in the arch-specific kconfigs of ARC and X86 (32-bit)
architectures even though these are defining the same things.
Move the common symbols in one place accessible by all the architectures
and create a menu for those.
Leave the default values in the arch-specific locations.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Until now, any attempts to call printk prior to early serial init has
caused page faults due to the device not being mapped yet. Add static
variable to track the pre-init status, and instead of page faulting
just suppress the characters and log a warning right after init to
give an indication that output characters have been lost.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The original idea of using a custom switch to main thread
function is to make sure the buffer to save floating point
registers are aligned correctly or else exception would be
raised when saving/restoring those registers. Since
the struct of the buffer is defined with alignment hint
to toolchain, the alignment will be enforced by toolchain
as long as the k_thread struct variable is a dedicated,
declared variable. So there is no need for the custom
switch to main thread function anymore.
This also allows the stack usage calculation of
the interrupt stack to function properly as the end of
the interrupt stack is not being used for the dummy
thread anymore.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Convert device to DEVICE_DEFINE instead of DEVICE_AND_API_INIT
so we can deprecate DEVICE_AND_API_INIT in the future.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Fix the following complilation error that happens when specifying a
fixed MMIO address for the UART through X86_SOC_EARLY_SERIAL_MMIO8_ADDR:
arch/x86/core/early_serial.c:30:26: error: #if with no expression
30 | #if DEVICE_MMIO_IS_IN_RAM
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Renamed to make its semantics clearer; this function maps
*physical* memory addresses and is not equivalent to
posix mmap(), which might confuse people.
mem_map test case remains the same name as other memory
mapping scenarios will be added in the fullness of time.
Parameter names to z_phys_map adjusted slightly to be more
consistent with names used in other memory mapping functions.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The page table implementation requires conversion between virtual
and physical addresses when creating and walking page tables. Add
a phys_addr() and virt_addr() functions instead of hard-casting
these values, plus a macro for doing the same in ASM code.
Currently, all pages are identity mapped so VIRT_OFFSET = 0, but
this will now still work if they are not the same.
ASM language was also updated for 32-bit. Comments were left in
64-bit, as long mode semantics don't allow use of Z_X86_PHYS_ADDR
macro; this can be revisited later.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Fix compiler warnings associated with 'level' and 'entry' variables
'may be used uninitialized in this function'
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
We now show:
- Data pages that are paged out in red
- Pages that are mapped but non-present due to KPTI,
respectively in cyan or blue if they are identity mapped
or not.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
With kernel page table isolation (KPTI) we cannot use right exception
stack since after using trampoline stack there was always switch to
7th IST stack (__x86_tss64_t_ist7_OFFSET). Make this configurable as a
parameter in EXCEPT(nr, ist) and EXCEPT_CODE(nr, ist). For the NMI we
would use ist6 (_nmi_stack).
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
