Tests of a value against zero should be made explicit, unless the
operand is effectively Boolean. This is based on MISRA rule 14.4.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This changes the assert when a large page is encountered to
copying the page directory entry to the new page directory.
This is needed when a large page entry is generated by
gen_mmu.py. Note that this still asserts when there are entries
of large page at higher level.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This makes the gen_mmu.py script to error out if the reserved space
for page table in zephyr_prebuilt.elf is not large enough to
accommodate the generated page table. Let catch this at build time
instead of mysterious hangs when loading the page table at boot.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The whole page table is pre-allocated at build time and is
dependent on the range of address space. This kconfig allows
reserving extra pages (of size CONFIG_MMU_PAGE_SIZE) to
the page table so that gen_mmu.py can make use of these
extra pages.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This patch replaces ENOSYS into ENOTSUP to keep consistency with
the return value specification of k_float_enable().
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
This patch introduce new API to enable FPU of thread. This is pair of
existed k_float_disable() API. And also add empty arch_float_enable()
into each architectures that have arch_float_disable(). The arc and
riscv already implemented arch_float_enable() so I do not touch
these implementations.
Motivation: Current Zephyr implementation does not allow to use FPU
on main and other system threads like as work queue. Users need to
create an other thread with K_FP_REGS for floating point programs.
Users can use FPU more easily if they can enable FPU on running
threads.
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
The only user of arch_mem_domain_destroy was the deprecated
k_mem_domain_destroy function which has now been removed. So remove
arch_mem_domain_destroy as well.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This unifies all the display of region size in hex.
Some of them are there to aid in figuring out the end of
a memory region so it is easier if they are already in hex.
This also fixes the display of address range where the end
is off by one and should be (base + size - 1).
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
After page table is load, we should be executing in virtual
address space. Therefore we need to set ESP to the virtual
address of interrupt stack for the boot process.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This reverts commit d40e8ede8e.
This fixes triple faults after wiping the identity mapping of
physical memory when running entering userspace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This reverts commit 7d32e9f9a5.
We now allow the kernel to be linked virtually. This patch:
- Properly converts between virtual/physical addresses
- Handles early boot instruction pointer transition
- Double-maps SRAM to both virtual and physical locations
in boot page tables to facilitate instruction pointer
transition, with logic to clean this up after completed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This reuses the page directory pointer table (PAE=y) or page
directory (PAE=n) to point to next level page directory table
(PAE=y) or page tables (PAE=n) to identity map the physical
memory. This gets rid of the extra memory needed to host
the extra mappings which are only used at boot. Following
patches will have code to actual unmap physical memory
during the boot process, so this avoids some wasting of
memory.
Since no extra memory needs to be reserved, this also reverts
commit ee3d345c09
("x86: mmu: reserve more space for page table if linking in virt").
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This allows specifying second --verbose in command line to
enable more messages. Two new ones have been added to aid
in debugging code for mapping and setting permission to
a single page.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
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>
Since the removal of Quark-based boards, there are no user of
Minute-IA. Also, the generic x86 SoC is not exactly Minute-IA
so change it to use a fairly safe CPU_ATOM.
Fixes#14442
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>
When linking in virtual address space, we still need physical
addressed 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 identity maps the kernel in SRAM.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
When the kernel is mapped into virtual address space
that is different than the physical address space,
the dynamic GDT generation uses the virtual addresses.
However, the GDT table is required at boot before
page table is loaded where the virtual addresses are
invalid. So make sure GDT generation is using
physical addresses.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
There is an assumption made in the page table generation code
that the kernel would occupy the same physical and virtual
addresses. However, we may want to map the kernel into
a virtual address space which differs from kernel's physical
address space. For example, with demand paging enabled on
kernel code and data, we can accommodate kernel that is
larger than physical memory size, and may want to utilize
a bigger virtual address space. So add address translation
in the gen_mmu.py script for this.
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>
This changes x86 to use CONFIG_SRAM_OFFSET instead of
arch-specific CONFIG_X86_KERNEL_OFFSET. This allows the common
MMU macro Z_BOOT_VIRT_TO_PHYS() and Z_BOOT_PHYS_TO_VIRT() to
function properly if we ever need to map the kernel into
virtual address space that does not have the same starting
physical address.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds a new kconfig CONFIG_SRAM_OFFSET to specify the offset
from beginning of SRAM where the kernel begins. On x86 and
PC compatible platforms, the first 1MB of RAM is reserved and
Zephyr should not link anything there. However, this 1MB still
needs to be mapped by the MMU to access various platform related
information. CONFIG_SRAM_OFFSET serves similar function as
CONFIG_KERNEL_VM_OFFSET and is needed for proper phys/virt
address translations.
Signed-off-by: Daniel Leung <daniel.leung@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>
This adds a new GEN_ABSOLUTE_SYM_KCONFIG() specifically for
generating absolute symbols in assembly for kconfig values.
This is needed as the existing GEN_ABSOLUTE_SYM() with
constraints in extended assembly parses the "value" as
signed 32-bit integers. An unsigned 32-bit integer with
MSB set results in a negative number in the final binary.
This also prevents integers larger than 32-bit. So this
new macro simply puts the value inline within the assembly
instrcution instead of having it as parameter.
Fixes#31562
Signed-off-by: Daniel Leung <daniel.leung@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>
