A function pointer under FDPIC is not a code address. Because each
PT_LOAD segment is placed independently, a pointer has to carry the data
base its callee will need, so it is a two-word descriptor: the entry
point, and the base to install in the PIC register before branching.
R_ARM_FUNCDESC_VALUE says "the thing you are patching is such a
descriptor", and R_ARM_FUNCDESC says "manufacture one and give me its
address".
Both need state a relocation cannot carry. A descriptor's second word is
the *object's* data base, from DT_PLTGOT, and R_ARM_FUNCDESC carves
descriptors from a pool whose cursor has to survive from one relocation
to the next. up_relocate() is handed only a relocation, a resolved
symbol and an address to patch.
arch_data is the existing channel for exactly this -- RISC-V already uses
it to remember a HI20 relocation while its LO12 partner is processed --
but nothing has ever put loader state into it: it is declared zeroed and
written only by up_relocate() itself. So ARCH_ELFDATA_INIT and
ARCH_ELFDATA_FINI are added, seeding the block from the loadinfo before
the relocation loop and reading the cursor back after. Both default to
nothing, so an architecture that does not define them is unaffected, and
RISC-V's use of arch_data is untouched. libelf_relocatedyn() walks both
dynamic tables under one arch_data, so the cursor spans the whole object.
The addend handling is the part that is easy to get wrong. REL format
keeps the addend in place, in the word about to become the entry point,
and a pointer to a static function is referenced through its *section*
symbol -- the value is the section base and the offset, including the
Thumb bit, is entirely in the addend. Dropping it yields an even address
and the core faults trying to execute it as ARM code.
The GOT written into a descriptor is the loading object's own, even for
an imported function, which is what makes a callback work: when the base
firmware's qsort() calls back into a module's comparison function, the
module needs its own data base in the PIC register.
libelf_relocatedyn()'s imported-symbol path needed a change to suit. It
stores the resolved address directly and never calls up_relocate(), which
cannot produce a two-word descriptor, so under FDPIC the resolved value
now goes through up_relocate() and the relocation type decides what to
write.
Implemented for armv7-m and armv8-m, the profiles FDPIC targets; the
other ARM variants gain the arch_data block but no new relocations.
Built and booted mps3-an547:picostest and lm3s6965-ek:qemu-nxflat, the
ELF PIC and NXFLAT users of this code, both unchanged.
Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
Both files put the body of the relocation switch at the same indent as the
switch braces, so nxstyle reports forty-four errors in each and any patch
whose hunks land near them fails the check job.
Giving the body its level takes the bit diagrams in the comments one column
past the line limit. The rulers say Instr rather than Instructions, which is
enough and is what the same rulers further down already do. A comment that
had no code on its line becomes a sentence of its own, and two that were a
column out are put right.
Whitespace and comments only. Compiled before and after for cortex-m7 and
cortex-m33: the disassembly is identical.
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
Add dedicated NEON implementations for mutually aligned medium and long memcpy copies when building with __ARM_NEON__. These paths use NEON multi-register loads and stores while preserving the existing VFP implementation for non-NEON VFP configurations.
NEON builds also define USE_VFP, so select the NEON implementation explicitly before falling back to VFP. Apply the same aligned-copy optimization to the armv7-a, armv7-r, and armv8-r implementations.
Signed-off-by: yaojiaqi <yaojiaqi@lixiang.com>
debug.h is a NuttX-specific, non-POSIX header. Placing it in the
top-level include/ directory creates naming conflicts with external
projects that define their own debug.h.
This commit moves the canonical header to include/nuttx/debug.h,
following the NuttX convention for non-POSIX/non-standard headers,
and updates all in-tree references.
A backward-compatibility shim is left at include/debug.h that
emits a deprecation #warning and re-includes <nuttx/debug.h>,
allowing out-of-tree code to continue building while migrating.
Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
Add support for ARMv6-M and ARMv8-M Baseline architectures
(Cortex-M0/M0+/M23) in the mcount profiling function. These cores
only support limited Thumb-1 instruction set and require different
assembly instructions compared to ARMv7-M and higher.
Changes:
- Use MOVS+BICS instead of BIC for bit clearing on M0/M23
- Separate register restore for limited push/pop instructions
- Use BX instead of direct POP to PC on M0/M23
Signed-off-by: yinshengkai <yinshengkai@bytedance.com>
when we build with greenhills compiler, if the exception_common function
is put into a separate section: ".text.exception_common", then the
address of exception_common function is an even number, for example "0x16a6c",
in this case, it will trigger the UsageFaults:INVSTATE error.
The reason for this error is that in the GHS compiler, a section declared
through the ".section" directive must specify at least the "a" attribute.
Otherwise, this section will not be linked into the final file, and this
is why the address of exception_common function is invalid.
The following is the official explanation in the GHS compiler documentation:
"The reason for this error is that in the GHS compiler, a section
declared through the .section directive must specify at least the "a"
attribute. Otherwise, this section will not be linked into the final
file. The following is the official explanation in the documentation:
"Sections that are intended be part of the final linked output should
have at least the `a` attribute"
and for GHS compiler, the .text section is recommended specify the
attribute of `ax`.
Signed-off-by: guoshichao <guoshichao@xiaomi.com>
Add back these functions since clang will use them.
This reverts "libs/libc/arm: use builtin routines instead of aliases of __aeabi_mem*"
and adds source files to cmake.
Signed-off-by: chenxiaoyi <chenxiaoyi@xiaomi.com>
Fix an issue on ARMv8-R where NEON is not supported.
When NEON is disabled, the assembly-optimized implementations
of memset and memcpy should not be used.
Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>
Optimize crc32 standard(poly:0x04C11DB7) and crc32
castagnoli(poly:0x1EDC6F41) with arm crc32 extension instructions.
For example, crc32 standard caculates(lookup crc32 table) 1812 bytes data,
reduced the time from 118 us to 14 us through optimization.
Performance improved ~700%
Signed-off-by: Jinliang Li <lijinliang1@lixiang.com>
kasan does not instrument the assembly function,
so it is checked in advance before calling.
If Kasan is not turned on, the speed and space will
be almost unchanged under compiler optimization.
Signed-off-by: anjiahao <anjiahao@xiaomi.com>
gprof can analyze code hot spots based on scheduled sampling.
After adding the "-pg" parameter when compiling, you can view the code call graph.
Signed-off-by: yinshengkai <yinshengkai@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>
There is a problem with the current elf loader for risc-v: when a pair of
PCREL_HI20 / LO12 relocations are encountered, it is assumed that these
will follow each other immediately, as follows:
label:
auipc a0, %pcrel_hi(symbol) // R_RISCV_PCREL_HI20
load/store a0, %pcrel_lo(label)(a0) // R_RISCV_PCREL_LO12_I/S
With this assumption, the hi/lo relocations are both done when a hi20
relocation entry is encountered, first to the current instruction (addr)
and to the next instruction (addr + 4).
However, this assumption is wrong. There is nothing in the elf relocation
specification[1] that mandates this. Thus, the hi/lo relocation always
needs to first fixup the hi-part, and when the lo-part is encountered, it
needs to find the corresponding hi relocation entry, via the given "label".
This necessitates (re-)visiting the relocation entries for the current
section as well as looking for "label" in the symbol table.
The NuttX elf loader does not allow such operations to be done in the
machine specific part, so this patch fixes the relocation issue by
introducing an architecture specific cache for the hi20 relocation and
symbol table entries. When a lo12 relocation is encountered, the cache
can be consulted to find the hi20 part.
[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc
Provide a way to only customize specific string operations,
such as for memcpy with the DMA capability by ROM.
Signed-off-by: yangdongdong <yangdongdong@xiaomi.com>
1. Update all CMakeLists.txt to adapt to new layout
2. Fix cmake build break
3. Update all new file license
4. Fully compatible with current compilation environment(use configure.sh or cmake as you choose)
------------------
How to test
From within nuttx/. Configure:
cmake -B build -DBOARD_CONFIG=sim/nsh -GNinja
cmake -B build -DBOARD_CONFIG=sim:nsh -GNinja
cmake -B build -DBOARD_CONFIG=sabre-6quad/smp -GNinja
cmake -B build -DBOARD_CONFIG=lm3s6965-ek/qemu-flat -GNinja
(or full path in custom board) :
cmake -B build -DBOARD_CONFIG=$PWD/boards/sim/sim/sim/configs/nsh -GNinja
This uses ninja generator (install with sudo apt install ninja-build). To build:
$ cmake --build build
menuconfig:
$ cmake --build build -t menuconfig
--------------------------
2. cmake/build: reformat the cmake style by cmake-format
https://github.com/cheshirekow/cmake_format
$ pip install cmakelang
$ for i in `find -name CMakeLists.txt`;do cmake-format $i -o $i;done
$ for i in `find -name *\.cmake`;do cmake-format $i -o $i;done
Co-authored-by: Matias N <matias@protobits.dev>
Signed-off-by: chao an <anchao@xiaomi.com>
* build-globals.sh
- Macros for defining symbols etc. based on assembler in use
- Use the System.map to get all the nuttx symbols
* libs/libc/modlib/modlib_globals.S
- Provide an empty skeleton. If the dynamic loading functions
are required then run build-global.sh after a clean build
using the skeleton. This will fill out the skeleton with the
symbols to be available to dynamically loaded modules.
* libs/libc/modlib/modlib_loadhdrs.c
- Fix case where there are no program headers are avaiable
* libs/libc/machine/arm/armv7-m/arch_elf.c
- Fix cast of error message parameters
* build-globals.sh
- Build the modlib_globals.S file used to resolve symbols when dynamically loading
* libs/libc/modlib/Make.defs
- Build modlib_globals.S for all targets
* libs/libc/modlib/modlib_load.c
- Calculate sizes and text/data addresses based on program headers rather than section headers
- Handle objects with no program headers
* libs/libc/modlib/modlib_bind.c
- Call modlib_readsym with pointer to symbol table
- Add modlib_relocatedyn to manage relocation of symbols with shared object (ET_DYN)
- Differentiate between ET_REL and ET_DYN objects
- Use arch independent symbol ELF_R_SYM
- Cast sizes to avoid warnings
* libs/libc/modlib/modlib_load.c
- Cast sizes to avoid warnings
* include/elf.h
- Add definitions that may be found in shared objects
* include/nuttx/lib/modlib.h
- Add parameter to modlib_readsym prototype
- Add prototypes for:
- modlib_insertsymtab
- modlib_findglobal
- Define Elf_Dyn and Elf_Off according to the elf architecture
- Add fields to mod_loadifno_s:
- Program headers
- Exported symbols
- Data section address
- Padding requirement
- Section index for dynamic symbol table
- Number of symbols exported
- Add prottotype for modlib_freesymtab
* libs/libc/dlfcn/lib_dlclose.c
- Free the symbol table when the dll is closed
* libs/libc/dlfcn/lib_dlopen.c
- Add dump of program headers to debug routine
- Differentiate between ET_REL and ET_DYN objects
* libs/libc/machine/arm/armv7-m/arch_elf.c
- Add handling of R_ARM_RELATIVE and R_ARM_JUMP slot relocation types
* libs/libc/modlib/modlib_loadshdrs.c
- Rename modlib_loadshdrs.c to modlib_loadhdrs.c
- Rename modlib_loadshdrs to modlib_loadhdrs
- Add code to load program headers
* libs/libc/modlib/modlib_symbols.c
- Define entry point structure
- Add offset parameter to modlib_symname() and use to find symbol names
- Add symtab section header parameter to modlib_readsym()
- Add offset parameter to modlib_symvalue() to locate symbol names
- Add modlib_insertsyntab() to create a symbol table for exporting and resolution
- Add findEP() to resolve a symbol in the modlib_global table
- Add modlib_findglobal() to find symbol in the modlib_global table
- Add modlib_freesymtab() to free the symbol table
* libs/libc/modlib/modlib_uninit.c
- Free header and sections from a module_loadinfo_s control block
* libs/libc/modlib/modlib_verify.c
- Handle ET_DYN shared objects
* libs/libc/modlib/modlib_globals.S
- Multi-target global table
- Define library APIs that may be resolved when loading a shared object
since symbols defined in arch/elf.h is also used in other case, for example:
CC: pthread/pthread_testcancel.c machine/arm/gnu_unwind_find_exidx.c:32:8: error: unknown type name '__EIT_entry'
32 | static __EIT_entry *__exidx_start_elf;
| ^~~~~~~~~~~
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Add the `LIBC_PREVENT_STRING_KERNEL` and `LIBC_PREVENT_STRING_USER`
that are meant to be selected by the chip if no libc implementation
is going to be built. If selected, neither NuttX's software version
of the libc nor any architecture-specific implementation will be
built in the kernel or in the userspace, respectively. In this
case, the linker may provide a ROM-defined version of the libc
functions instead.
