ARM PIC has used r10 as the base register, but the tree has never been
consistent about it. Toolchain.defs gives CONFIG_BUILD_PIC
-mpic-register=r9 and CONFIG_PIC -mpic-register=r10, twenty-five lines
apart, and arm_initialstate.c sets REG_R9 from inline assembly under one
and REG_PIC under the other, with a comment reading "Set the PIC base
register (probably R10)". This settles it on r9 for all of PIC: NXFLAT,
ELF PIC and CONFIG_BUILD_PIC alike.
r9 is the right choice rather than an arbitrary one. It is the AAPCS
platform register, the "static base", and it is what GCC itself picks
for -msingle-pic-base on an EABI target; r10 is the non-EABI default.
It also removes a combination that cannot build today. Stack checking
adds -ffixed-r10 in armv7-m/Toolchain.defs and armv8-m/Toolchain.defs,
while CONFIG_PIC adds -mpic-register=r10, and GCC rejects the pair with
"unable to use 'r10' for PIC register". The comment above REG_PIC has
always said the register "can be R9 if stack checking is enabled", but
the definition was unconditionally REG_R10, so it would have named the
wrong register even had the build succeeded.
The thunk generator moves with the firmware. NXFLAT import stubs had
the register baked in as "add ip,ip,sl", so a module built for r9 would
load and then branch to a wild address on its first call out. The stubs
now come from NXFLAT_PIC_REG in the in-tree tool, which is built only
when CONFIG_NXFLAT is set, following the
CONFIG_BOARD_ETC_ROMFS_PASSWD_ENABLE precedent in tools/Unix.mk.
That leaves modules built before this change, and they are the reason
for the ABI marker. The NXFLAT header cannot carry a version: h_magic
is written by ldnxflat, which is GPL, derived from elf2flt, and stays
out of this repository, so it can never be changed in step with the
loader. The import table can, because both of its ends are in-tree --
mknxflat emits it and nxflat_bindimports() reads it -- and ldnxflat
passes it through untouched. So every module now imports
__nxflat_abi_v2, the base firmware defines it, and a module that does
not import it is refused.
Making the marker a real exported symbol rather than a name the loader
special-cases is what keeps it out of the build system's way: a board's
symbol table picks it up exactly as it picks up printf, so mksymtab.sh
and its equivalents need no change. It also gives the reverse direction
a diagnosis for free -- a module built against a newer ABI than its
firmware fails with "Exported symbol __nxflat_abi_v2 not found".
Most of the remaining churn is boards restating a default. ARCHPICFLAGS
is a "?=" default so that a board only speaks up when it differs, and
twenty-six were assigning the value the default already had. MKNXFLAT
gets the same treatment: thirteen boards named the same tool, and the
only thing that varies is ARM versus Thumb-2, which falls out of
CONFIG_ARM_THUMB. LDNXFLAT gains a default too -- it stays an
out-of-tree PATH lookup, but naming it centrally fixes boards that never
assigned it, where it expanded to nothing and handed make a recipe
beginning "-e", whose leading dash make ate as "ignore errors".
The non-ARM boards carrying -mpic-register=r10 lose it: it is an
ARM-only option, reachable only through CPICFLAGS, which is only used to
build NXFLAT modules, and no non-ARM board enables NXFLAT.
Boards keep nothing about PIC flags any more. ARCHPICFLAGS was set by
sixty-three of them and only ever fed CPICFLAGS, which is only used to
build NXFLAT modules; no board outside arch/arm enables NXFLAT, so every
non-ARM copy was setting a variable nothing read. Those are removed
rather than moved somewhere more central, which would only make dead
text look load-bearing. LDNXFLAT goes the same way as MKNXFLAT, for the
same reason: thirteen boards named the same tool that Toolchain.defs now
names once.
One of them was not merely redundant. am67/t3-gem-o1 asked for
"-mpic-register=r10 -ffixed-r10", which GCC refuses outright with
"unable to use 'r10' for PIC register" -- the very combination the
filter-out machinery in Toolchain.defs exists to prevent. It has
survived because that board does not build NXFLAT modules, so the flags
are never handed to a compiler. Renaming the register would have
carried the fault forward unchanged, so the line goes.
Tested on lm3s6965-ek:qemu-nxflat under QEMU, configured and built with
no overrides. The nxflat example runs the errno, hello and struct
modules with output identical to the same config built from master.
Built with the old out-of-tree thunk generator instead, the same
firmware refuses all three with ENOEXEC rather than locking up in a
HardFault, which is what this change is for. mps3-an547:picostest,
which is CONFIG_PIC without CONFIG_NXFLAT, builds clean and does not
build the thunk generator.
The .def files pick up two cosmetic changes here alongside the register:
a "Dyanamic" typo that codespell rejects, and a reworded comment in each
thunk_*.c. Neither appears in the emitted thunk -- both are in C
comments -- so the generated text is still what the upstream tool
produces, modulo the register itself.
BREAKING CHANGE: ARM PIC moves from r10 to r9. An NXFLAT module built
before this change has r10 baked into its import stubs and will not run
against a firmware carrying it; the two cannot be mixed. The module is
refused with ENOEXEC rather than branching to a wild address, by way of the
__nxflat_abi_v2 marker described below.
Quick fix: rebuild the module against this tree. Its source needs no
change. A board that reserved r10 by hand, or that assigned ARCHPICFLAGS
or MKNXFLAT to restate a default, should drop those assignments; nothing
else is affected, and CONFIG_PIC without CONFIG_NXFLAT needs no action.
Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
Add support to disable signals actions related struct
Co-authored-by: guoshichao <guoshichao@xiaomi.com>
Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>
Inline & inline_function both used make confuze, let's modify all inline
in irq.h to inline_function, also clear the always_inline_funcion
declaration.
Signed-off-by: buxiasen <buxiasen@xiaomi.com>
reason:
svc call may trigger hardfault
Background
The origin of this issue is our desire to eliminate the function of storing
"regs" in g_current_regs and instead utilize (*running_task)->xcp.regs for storage.
The benefits of this approach include faster storage speed and
avoiding multiple accesses to g_current_regs during context switching,
thus ensuring that whether returning from an interrupt or an exception,
we consistently use this_task()->xcp.regs
Issue Encountered
However, when storing registers, we must ensure that (running_task)->xcp.regs is invalid
so that it can be safely overwritten.
According to the existing logic, the only scenario where (running_task)->xcp.regs
is valid is during restore_context. We must accurately identify this scenario.
Initially, we used the condition (running_task)==NULL for this purpose, but we deemed
this approach unsatisfactory as it did not align well with the actual logic.
(running_task) should not be NULL. Consequently, we adopted other arch-specific methods for judgment,
but due to special logic in some arch, the judgment was not accurate, leading to this issue.
Solution:
For armv6-m, we haven't found a more suitable solution, so we are sticking with (*running_task)==NULL.
For armv7-m/armv8-m, by removing support for primask, we can achieve accurate judgment.
PRIMASK is a design in armv6-m, that's why arm introduce BASEPRI from armv7-m.
It's wrong to provide this option for armv7-m/armv8-m arch.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
reason:
up_set_current_regs initially had two functions:
1: To mark the entry into an interrupt state.
2: To record the context before an interrupt/exception. If we switch to
a new task, we need to store the upcoming context regs by calling up_set_current_regs(regs).
Currently, we record the context in other ways, so the second function is obsolete.
Therefore, we need to rename up_set_current_regs to better reflect its actual meaning,
which is solely to mark an interrupt.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
when we build mbedtls in vela with ghs compiler, the mbedtls need to
access __ARM_ARCH and __ARM_FEATURE_DSP, and to construct the inline asm
code based on these two macros.
With ghs compiler, these two macros are not defined, and will be
evaluated as 0 by default, and thus will using to wrong inline asm code,
in order to handle this issue, we need to add conversion between the ghs
and gcc with __ARM_ARCH, __ARM_FEATURE_DSP
Signed-off-by: guoshichao <guoshichao@xiaomi.com>
Some app with same code runs on different cores in AMP mode,
need the physical core on which the function is called.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>
resson:
using percpu storage for g_current_regs or leveraging interrupt status
registers to determine if code is running within an interrupt context can enhance performance.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
In protected build mode, the syscall returns without setting correct value for the CONTROL register, which causes the userspace threads working in privileged mode after syscall.
Signed-off-by: pangzhen1 <pangzhen1@xiaomi.com>
Notify the compiler that the condition flag has changed to prevent the
compiler from optimizing and reordering instructions, which may cause exceptions.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
arm-none-eabi-gcc 12.2.0 gives the following warnings:
error: 'primask' is used uninitialized
error: 'primask' may be used uninitialized
We use Werror and the file is indirectly included in different
places. I suggest telling the compiler to ignore these warnings
since primask is initialized on the first assembly line.
This is the only problem I encountered so far when upgrading the compiler.
since it is broken and inefficient, and then removed by:
commit dc961baaea
Author: chao.an <anchao@xiaomi.com>
Date: Thu Apr 14 18:07:14 2022 +0800
arm/armv7-[a|r]: move fpu save/restore to assembly handler
Save/Restore FPU registers in C environment is dangerous practive,
which cannot guarantee the compiler won't generate the assembly code
with float point registers, especially in interrupt handling
Signed-off-by: chao.an <anchao@xiaomi.com>
commit 8d66dbc068
Author: chao.an <anchao@xiaomi.com>
Date: Thu Apr 7 13:48:04 2022 +0800
arm/armv[7|8]-m: skip the fpu save/restore if stack frame is integer-only
Signed-off-by: chao.an <anchao@xiaomi.com>
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
The current context save implementation saves registers of each task
to xcp context, which is unnecessary because most of the arm registers are
already saved in the task stack, this commit replace the xcp context with
stack context to improve context switching performance and reduce the tcb
space occupation of tcb instance.
Signed-off-by: chao.an <anchao@xiaomi.com>
In AArch32, the frame pointer is stored in register R11 for ARM code or register R7 for Thumb code.
In AArch64, the frame pointer is stored in register X29.
Signed-off-by: chao.an <anchao@xiaomi.com>
If we are using the BASEPRI register to disable interrupts, then the answer is that we must disable ONLY the "normal interrupts". That is because we cannot disable SVCALL interrupts and we cannot permit SVCAll interrupts running at a higher priority than the high priority interrupts (otherwise, they will introduce jitter in the high priority interrupt response time.)
Hence, if you need to disable the high priority interrupt, you will have to disable the interrupt either at the peripheral that generates the interrupt or at the NVIC. Disabling global interrupts via the BASEPRI register cannot effect high priority interrupts.
libs/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
syscall/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
wireless/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
Documentation/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
include/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
drivers/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
sched/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
configs: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/xtensa: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/z80: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/x86: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/renesas and arch/risc-v: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/or1k: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/misoc: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/mips: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/avr: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/arm: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
