This is a first cut on a tool that will convert a built Zephyr ELF
file into an EFI applciation suitable for launching directly from the
firmware of a UEFI-capable device, without the need for an external
bootloader.
It works by including the Zephyr sections into the EFI binary as
blobs, then copying them into place on startup.
Currently, it is not integrated in the build. Right now you have to
build an image for your target (up_squared has been tested) and then
pass the resulting zephyr.elf file as an argument to the
arch/x86/zefi/zefi.py script. It will produce a "zephyr.efi" file in
the current directory.
This involved a little surgery in x86_64 to copy over some setup that
was previously being done in 32 bit mode to a new EFI entry point.
There is no support for 32 bit UEFI targets for toolchain reasons.
See the README for more details.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The traditional IO Port configuration mechanism was technically
deprecated about 15 years ago when PCI Express started shipping.
While frankly the MMIO support is significantly more complicated and
no more performant in practice, Zephyr should have support for current
standards. And (particularly complicated) devices do exist in the
wild whose extended capability pointers spill beyond the 256 byte area
allowed by the legacy mechanism. Zephyr will want drivers for those
some day.
Also, Windows and Linux use MMIO access, which means that's what
system vendors validate.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The existing minimal ACPI implementation was enough to find the MADT
table for dumping CPU info. Enhance it with a slightly less minimal
implementation that can fetch any table, supports the ACPI 2.0 XSDT
directory (technically required on 64 bit systems so tables can live
>4G) and provides definitions for the MCFG table with the PCI
configuration pointers.
Note that there is no use case right now for high performance table
searching, so the "init" step has been removed and tables are probed
independently from scratch for each one requested (there are only
two).
Note also that the memory to which these tables point is not
understood by the Zephyr MMU configuration, so in long mode all ACPI
calls have to be done very early, before z_x86_paging_init() (or on a
build with the MMU initialization disabled).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
If we get a page fault in early boot context, before
main thread is started, page faults were being
incorrectly reported as stack overflows.
z_x86_check_stack_bounds() needs to consider the
interrupt stack as the correct stack for this context.
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>
This helps distingush between fatal errors if logging isn't
enabled.
As detailed in comments, pass a reason code which controls
the QEMU process' return value.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
x86_64's __resume path 'poisons' the incoming thread's
saved RIP value with a special 0xB9 value, to catch
re-use of thread objects across CPUs in SMP. Add a check
and printout for this when handling fatal errors, and
treat as a kernel panic.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If KPTI is not enabled, the current value of CR3 is the correct
page tables when the exception happened in all cases.
If KPTI is enabled, and the excepting thread was in user mode,
then a page table switch happened and the current value of CR3
is not the page tables when the fault happened. Get it out of the
thread object instead.
Fixes two problems:
- Divergent exception loop if we crash when _current is a dummy
thread or its page table pointer stored in the thread object is
NULL or uninitialized
- Printing the wrong CR3 value on exceptions from user mode in
the register dump
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
In one of the ASSERT() statement, the PHYS_RAM_ADDR (alias
of DT_REG_ADDR()) may be interpreted by the compiler as
long long int when it's large than 0x7FFFFFFF, but is
paired with %x, resulting in compiler warning. Fix this
by type casting it to uintptr_t and use %lx instead.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
On x86_64, the arch_timing_* variables are not set which
results in incorrect values being used in the timing_info
benchmarks. So instrument the code for those values.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The SoCs usually have devices that are accessed through MMIO.
This requires the corresponding regions to be marked readable
and writable in the MMU or else accesses will result in page
faults.
This adds a function which can be implemented in the SoC code to
specify those pages to be added to MMU.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The integers used for pointer calculation were u32_t.
Change them to uintptr_t to be compatible with 64-bit.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
x86-32 thread objects require special alignment since they
contain a buffer that is passed to fxsave/fxrstor instructions.
This fell over if the dummy thread is created in a stack frame.
Implement a custom swap to main for x86 which still uses a
dummy thread, but in an unused part of the interrupt stack
with proper alignment.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If IO APIC is in logical destination mode, local APICs compare their
logical APIC ID defined in LDR (Logical Destination Register) with
the destination code sent with the interrupt to determine whether or not
to accept the incoming interrupt.
This patch programs LDR in xAPIC mode to support IO APIC logical mode.
The local APIC ID from local APIC ID register can't be used as the
'logical APIC ID' because LAPIC ID may not be consecutive numbers hence
it makes it impossible for LDR to encode 8 IDs within 8 bits.
This patch chooses 0 for BSP, and for APs, cpu_number which is the index
to x86_cpuboot[], which ultimately assigned in z_smp_init[].
Signed-off-by: Zide Chen <zide.chen@intel.com>
This commit renames the x86 Kconfig `CONFIG_{EAGER,LAZY}_FP_SHARING`
symbol to `CONFIG_{EAGER,LAZY}_FPU_SHARING`, in order to align with the
recent `CONFIG_FP_SHARING` to `CONFIG_FPU_SHARING` renaming.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit renames the Kconfig `FP_SHARING` symbol to `FPU_SHARING`,
since this symbol specifically refers to the hardware FPU sharing
support by means of FPU context preservation, and the "FP" prefix is
not fully descriptive of that; leaving room for ambiguity.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This expands the early_serial to support MMIO UART, in addition to
port I/O, by duplicating part of the hardware initialization from
the NS16550 UART driver. This allows enabling of early console on
hardware with MMIO-based UARTs.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
x86_64 supports 4 levels of interrupt nesting, with
the interrupt stack divided up into sub-stacks for
each nesting level.
Unfortunately, the initial interrupt stack pointer
on the first CPU was not taking into account reserved
space for guard areas, causing a stack overflow exception
when attempting to use the last interrupt nesting level,
as that page had been set up as a stack guard.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We need to lock interrupts before setting the thread's
stack pointer to the trampoline stack. Otherwise, we
could unexpectedly take an interrupt on this stack
instead of the thread stack as intended.
The specific problem happens at the end of the interrupt,
when we switch back to the thread stack and call swap.
Doing this on a per-cpu trampoline stack instead of the
thread stack causes data corruption.
Fixes: #24869
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Replace DT_PHYS_RAM_ADDR and DT_RAM_SIZE with DT_REG_ADDR/DT_REG_SIZE
for the DT_CHOSEN(zephyr_sram) node.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This commit renames the Kconfig `FLOAT` symbol to `FPU`, since this
symbol only indicates that the hardware Floating Point Unit (FPU) is
used and does not imply and/or indicate the general availability of
toolchain-level floating point support (i.e. this symbol is not
selected when building for an FPU-less platform that supports floating
point operations through the toolchain-provided software floating point
library).
Moreover, given that the symbol that indicates the availability of FPU
is named `CPU_HAS_FPU`, it only makes sense to use "FPU" in the name of
the symbol that enables the FPU.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
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 core kernel z_setup_new_thread() calls into arch_new_thread(),
which calls back into the core kernel via z_new_thread_init().
Move everything that doesn't have to be in z_new_thread_init() to
z_setup_new_thread() and convert to an inline function.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Those are used only in tests, so remove them from kernel Kconfig and set
them in the tests that use them directly.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The set of interrupt stacks is now expressed as an array. We
also define the idle threads and their associated stacks this
way. This allows for iteration in cases where we have multiple
CPUs.
There is now a centralized declaration in kernel_internal.h.
On uniprocessor systems, z_interrupt_stacks has one element
and can be used in the same way as _interrupt_stack.
The IRQ stack for CPU 0 is now set in init.c instead of in
arch code.
The extern definition of the main thread stack is now removed,
this doesn't need to be in a header.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Change to code to use the automatically generated DT_INST_*
defines and remove the now unneeded configs and fixups.
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
If IO APIC is in logical destination mode, local APICs compare their
logical APIC ID defined in LDR (Logical Destination Register) with
the destination code sent with the interrupt to determine whether or not
to accept the incoming interrupt.
This patch programs LDR in xAPIC mode to support IO APIC logical mode.
The local APIC ID from local APIC ID register can't be used as the
'logical APIC ID' because LAPIC ID may not be consecutive numbers hence
it makes it impossible for LDR to encode 8 IDs within 8 bits.
This patch chooses 0 for BSP, and for APs, cpu_number which is the index
to x86_cpuboot[], which ultimately assigned in z_smp_init[].
Signed-off-by: Zide Chen <zide.chen@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>
The context switch implementation forgot to save the current flag
state of the old thread, so on resume the flags would be restored to
whatever value they had at the last interrupt preemption or thread
initialization. In practice this guaranteed that the interrupt enable
bit would always be wrong, becuase obviously new threads and preempted
ones have interrupts enabled, while arch_switch() is always called
with them masked. This opened up a race between exit from
arch_switch() and the final exit path in z_swap().
The other state bits weren't relevant -- the oddball ones aren't used
by Zephyr, and as arch_switch() on this architecture is a function
call the compiler would have spilled the (caller-save) comparison
result flags anyway.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Use of the _current_cpu pointer cannot be done safely in a preemptible
context. If a thread is preempted and migrates to another CPU, the
old CPU record will be wrong.
Add a validation assert to the expression that catches incorrect
usages, and fix up the spots where it was wrong (most important being
a few uses of _current outside of locks, and the arch_is_in_isr()
implementation).
Note that the resulting _current expression now requires locking and
is going to be somewhat slower. Longer term it's going to be better
to augment the arch API to allow SMP architectures to implement a
faster "get current thread pointer" action than this default.
Note also that this change means that "_current" is no longer
expressible as an lvalue (long ago, it was just a static variable), so
the places where it gets assigned now assign to _current_cpu->current
instead.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Add TRACING_ISR Kconfig to help high latency backend working well.
Currently the ISR tracing hook function is put at the begining and
ending of ISR wrapper, when there is ISR needed in the tracing path
(especially tracing backend), it will cause tracing buffer easily
be exhausted if async tracing method enabled. Also it will increase
system latency if all the ISRs are traced. So add TRACING_ISR to
enable/disable ISR tracing here. Later a filter out mechanism based
on irq number will be added.
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
There was a bug where double-dispatch of a single thread on multiple
SMP CPUs was possible. This can be mind-bending to diagnose, so when
CONFIG_ASSERT is enabled add an extra instruction to __resume (the
shared code path for both interupt return and context switch) that
poisons the shared RIP of the now-running thread with a recognizable
invalid value.
Now attempts to run the thread again will crash instantly with a
discoverable cookie in their instruction pointer, and this will remain
true until it gets a new RIP at the next interrupt or switch.
This is under CONFIG_ASSERT because it meets the same design goals of
"a cheap test for impossible situations", not because it's part of the
assertion framework.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The original intent was that the output handle be written through the
pointer in the second argument, though not all architectures used that
scheme. As it turns out, that write is becoming a synchronization
signal, so it's no longer optional.
Clarify the documentation in arch_switch() about this requirement, and
add an instruction to the x86_64 context switch to implement it as
original envisioned.
Signed-off-by: Andy Ross <andrew.j.ross@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>
generated_dts_board.h is pretty redundant and confusing as a name. Call
it devicetree.h instead.
dts.h would be another option, but DTS stands for "devicetree source"
and is the source code format, so it's a bit confusing too.
The replacement was done by grepping for 'generated_dts_board' and
'GENERATED_DTS_BOARD'.
Two build diagram and input-output SVG files were updated as well, along
with misc. documentation.
hal_ti, mcuboot, and ci-tools updates are included too, in the west.yml
update.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
KPTI is still work-in-progress on x86_64. Don't allow
user mode to be enabled unless the SOC/board configuration
indicates that the CPU in use is invulnerable to meltdown
attacks.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
See CVE-2019-1125. We mitigate this by adding an 'lfence'
upon interrupt/exception entry after the decision has been
made whether it's necessary to invoke 'swapgs' or not.
Only applies to x86_64, 32-bit doesn't use swapgs.
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>
This code:
1) Doesn't work
2) Hasn't ever been enabled by default
3) We mitigate Spectre V2 via Extended IBRS anyway
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>
