src/appendix/additional-resources.md - rust-lang/rustc-dev-guide - Git at Google


            
            # Additional Resources


            ## ABIs and Platform Specifics


            ### System V


            The System V ABIs are defined by a General ABI (gABI), which cross-platform things like linking

            
            behavior and the ELF format, and by processor-speciic ABIs (psABI) that define data layout and

            
            calling convention. The gABI can be found at <https://www.sco.com/developers/gabi/>.


            #### ARM (Arm32 and AArch64)


            ABIs are located at <https://github.com/ARM-software/abi-aa>. The aapcs32 and aapcs64 directories

            
            are likely the most interesting. These ABIs are actively developed and discussed at that repository.


            #### AMDGPU


            The LLVM guide at <https://llvm.org/docs/AMDGPUUsage.html> is likely the best collection of

            
            resources for this architecture.


            #### AVR


            The AVR calling convention is detailed at the GCC Wiki, <https://gcc.gnu.org/wiki/avr-gcc>. The

            
            wiki is actively updated as needed.


            #### BPF


            A minimal ABI is defined at <https://docs.kernel.org/bpf/standardization/abi.html>.


            #### CSky


            The LLVM documentation links to <https://github.com/c-sky/csky-doc/tree/master>, which contains

            
            a document `C-SKY_V2_CPU_Applications_Binary_Interface_Standards_Manual.pdf`.


            #### Hexagon


            The Hexagon ABI can be found at <https://docs.qualcomm.com/doc/80-N2040-23/topic/>.


            #### Loongarch


            ABIs are located at <https://github.com/loongson/la-abi-specs>, with a rendered version at

            
            <https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html>. This ABI is actively

            
            developed and discussed at that repository.


            #### m68k


            An ABI is described at <https://m680x0.github.io/doc/abi.html>.


            #### MIPS


            The o32 ("old 32") ABI is described in [_System V Application Binary Interface: MIPS

            
            RISC Processor Supplement_](https://refspecs.linuxfoundation.org/elf/mipsabi.pdf).

            
            The n32 and n64 ("new 32" and "new 64") ABIs are described in the [_MIPSproTM N32 ABI

            
            Handbook_](https://irix7.com/techpubs/007-2816-005.pdf). There is also a porting guide for n64 that

            
            may be helpful <https://irix7.com/techpubs/007-2391-006.pdf>.


            #### MSP430


            The document _MSP430 Embedded Application Binary Interface_ is available at

            
            <https://www.ti.com/lit/an/slaa534a/slaa534a.pdf>.


            #### NVPTX


            LLVM documentation directs to <https://docs.nvidia.com/cuda/index.html>.


            #### PowerPC


            There are a few relevant documents for PowerPC ABI:


            * [_System V Application Binary Interface: PowerPC Processor

            
              Supplement_](https://refspecs.linuxfoundation.org/elf/elfspec_ppc.pdf) is the original 32-bit

            
              PowerPC ABI specification.

            
            * [_Power Architecture™ 32-bit Application Binary Interface Supplement 1.0 - Linux® &

            
              Embedded_](https://web.archive.org/web/20120608163804/https://www.power.org/resources/downloads/Power-Arch-32-bit-ABI-supp-1.0-Unified.pdf)

            
              (web archive) is the latest version of the 32-bit ABI. Its source is hosted at

            
              <https://github.com/ryanarn/powerabi> but effectively unmaintained.

            
            * [_64-bit PowerPC ELF Application Binary Interface Supplement

            
              1.9_](https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html) is the original 64-bit

            
              ABI, last updated in 2004. This is known as ELFv1, and still used by default on some big endian

            
              PowerPC64 targets.

            
            * [_64-bit ELF V2 ABI Specification: Power

            
              Architecture_](https://openpower.foundation/specifications/64bitelfabi/) is the replacement ABI

            
              and used by default on most PowerPC64 targets.


            #### RISC-V


            Ratified RISC-V ABIs are located at <https://docs.riscv.org/reference/abi/v1.0/index.html>. More

            
            recent snapshots can be viewed at <https://riscv-non-isa.github.io/riscv-elf-psabi-doc/>, with

            
            development happening at <https://github.com/riscv-non-isa/riscv-elf-psabi-doc>.


            #### s390x


            The ABI is located at <https://github.com/IBM/s390x-abi> with a published PDF available at

            
            <https://ibm.github.io/s390x-abi/lzsabi_s390x.pdf>. This ABI is actively developed and discussed

            
            at that repository.


            Historical ISAs can be found at <https://linux.mainframe.blog/zarchitecture-principles-of-operation/>.

            
            <https://maskray.me/blog/toolchain-notes-on-z-architecture> has a great overview of other ABI

            
            components such as linking and TLS.


            #### SPARC


            _SCD 2.4.1_ available at <https://sparc.org/technical-documents/specifications/> describes both the

            
            32-bit and 64-bit ABIs. _SPARC psABI 3.0_, available at that same link, is an older description of

            
            the 32-bit ABI.


            #### x86


            The 32-bit ABI (i386) is located at <https://gitlab.com/x86-psABIs/i386-ABI>. The 64-bit ABI (amd64)

            
            is located at <https://gitlab.com/x86-psABIs/x86-64-ABI/#elf-x86-64-abi-psabi>. Both of these are

            
            actively developed and discussed on mailing lists at <https://groups.google.com/g/ia32-abi> and

            
            <https://groups.google.com/g/x86-64-abi>.


            #### Xtensa


            TODO


            ### Apple


            Apple largely follows the System V ABIs but documents a few exceptions at the following links:


            * Arm64: <https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms>

            
            * x86: <https://developer.apple.com/documentation/xcode/writing-64-bit-intel-code-for-apple-platforms>


            ### Microsoft


            Microsoft's x86-64 ABI is defined at <https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions>.

            
            There are a few different x86-32 conventions:


            * Cdecl (default): <https://learn.microsoft.com/en-us/cpp/cpp/cdecl>

            
            * Stdcall: <https://learn.microsoft.com/en-us/cpp/cpp/stdcall>

            
            * Fastcall: <https://learn.microsoft.com/en-us/cpp/cpp/fastcall>

            
            * Thiscall: <https://en.wikipedia.org/wiki/X86_calling_conventions#thiscall>


            As well as a few that aren't supported by Rust (`__clrcall`, `__vectorcall`, `__preserve_none`).


            Aarch64 targets generally use the AAPCS64 calling convention. There are some exceptions listed at

            
            <https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170>.


            Register mappings for arm64ec are documented at

            
            <https://learn.microsoft.com/en-us/cpp/build/arm64ec-windows-abi-conventions?view=msvc-170>.

            
            <http://www.emulators.com/docs/abc_arm64ec_explained.htm> does a great job of explaining more about

            
            how this works.


            #### Wasm


            The way that C types are broken down into Wasm types is described at

            
            <https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md>.


            ### Additional Resources for Platform Specifics


            The following links aggregate more resources


            * Links to other resources such as ELF and DWARF: <https://refspecs.linuxfoundation.org/>

            
            * Links to a number of standards including ISAs <https://llvm.org/docs/CompilerWriterInfo.html>

            
            * More about System V ABIs, especially x86: <https://wiki.osdev.org/System_V_ABI>
	# Additional Resources

	## ABIs and Platform Specifics

	### System V

	The System V ABIs are defined by a General ABI (gABI), which cross-platform things like linking
	behavior and the ELF format, and by processor-speciic ABIs (psABI) that define data layout and
	calling convention. The gABI can be found at <https://www.sco.com/developers/gabi/>.

	#### ARM (Arm32 and AArch64)

	ABIs are located at <https://github.com/ARM-software/abi-aa>. The aapcs32 and aapcs64 directories
	are likely the most interesting. These ABIs are actively developed and discussed at that repository.

	#### AMDGPU

	The LLVM guide at <https://llvm.org/docs/AMDGPUUsage.html> is likely the best collection of
	resources for this architecture.

	#### AVR

	The AVR calling convention is detailed at the GCC Wiki, <https://gcc.gnu.org/wiki/avr-gcc>. The
	wiki is actively updated as needed.

	#### BPF

	A minimal ABI is defined at <https://docs.kernel.org/bpf/standardization/abi.html>.

	#### CSky

	The LLVM documentation links to <https://github.com/c-sky/csky-doc/tree/master>, which contains
	a document `C-SKY_V2_CPU_Applications_Binary_Interface_Standards_Manual.pdf`.

	#### Hexagon

	The Hexagon ABI can be found at <https://docs.qualcomm.com/doc/80-N2040-23/topic/>.

	#### Loongarch

	ABIs are located at <https://github.com/loongson/la-abi-specs>, with a rendered version at
	<https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html>. This ABI is actively
	developed and discussed at that repository.

	#### m68k

	An ABI is described at <https://m680x0.github.io/doc/abi.html>.

	#### MIPS

	The o32 ("old 32") ABI is described in [_System V Application Binary Interface: MIPS
	RISC Processor Supplement_](https://refspecs.linuxfoundation.org/elf/mipsabi.pdf).
	The n32 and n64 ("new 32" and "new 64") ABIs are described in the [_MIPSproTM N32 ABI
	Handbook_](https://irix7.com/techpubs/007-2816-005.pdf). There is also a porting guide for n64 that
	may be helpful <https://irix7.com/techpubs/007-2391-006.pdf>.

	#### MSP430

	The document _MSP430 Embedded Application Binary Interface_ is available at
	<https://www.ti.com/lit/an/slaa534a/slaa534a.pdf>.

	#### NVPTX

	LLVM documentation directs to <https://docs.nvidia.com/cuda/index.html>.

	#### PowerPC

	There are a few relevant documents for PowerPC ABI:

	* [_System V Application Binary Interface: PowerPC Processor
	Supplement_](https://refspecs.linuxfoundation.org/elf/elfspec_ppc.pdf) is the original 32-bit
	PowerPC ABI specification.
	* [_Power Architecture™ 32-bit Application Binary Interface Supplement 1.0 - Linux® &
	Embedded_](https://web.archive.org/web/20120608163804/https://www.power.org/resources/downloads/Power-Arch-32-bit-ABI-supp-1.0-Unified.pdf)
	(web archive) is the latest version of the 32-bit ABI. Its source is hosted at
	<https://github.com/ryanarn/powerabi> but effectively unmaintained.
	* [_64-bit PowerPC ELF Application Binary Interface Supplement
	1.9_](https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html) is the original 64-bit
	ABI, last updated in 2004. This is known as ELFv1, and still used by default on some big endian
	PowerPC64 targets.
	* [_64-bit ELF V2 ABI Specification: Power
	Architecture_](https://openpower.foundation/specifications/64bitelfabi/) is the replacement ABI
	and used by default on most PowerPC64 targets.

	#### RISC-V

	Ratified RISC-V ABIs are located at <https://docs.riscv.org/reference/abi/v1.0/index.html>. More
	recent snapshots can be viewed at <https://riscv-non-isa.github.io/riscv-elf-psabi-doc/>, with
	development happening at <https://github.com/riscv-non-isa/riscv-elf-psabi-doc>.

	#### s390x

	The ABI is located at <https://github.com/IBM/s390x-abi> with a published PDF available at
	<https://ibm.github.io/s390x-abi/lzsabi_s390x.pdf>. This ABI is actively developed and discussed
	at that repository.

	Historical ISAs can be found at <https://linux.mainframe.blog/zarchitecture-principles-of-operation/>.
	<https://maskray.me/blog/toolchain-notes-on-z-architecture> has a great overview of other ABI
	components such as linking and TLS.

	#### SPARC

	_SCD 2.4.1_ available at <https://sparc.org/technical-documents/specifications/> describes both the
	32-bit and 64-bit ABIs. _SPARC psABI 3.0_, available at that same link, is an older description of
	the 32-bit ABI.

	#### x86

	The 32-bit ABI (i386) is located at <https://gitlab.com/x86-psABIs/i386-ABI>. The 64-bit ABI (amd64)
	is located at <https://gitlab.com/x86-psABIs/x86-64-ABI/#elf-x86-64-abi-psabi>. Both of these are
	actively developed and discussed on mailing lists at <https://groups.google.com/g/ia32-abi> and
	<https://groups.google.com/g/x86-64-abi>.

	#### Xtensa

	TODO

	### Apple

	Apple largely follows the System V ABIs but documents a few exceptions at the following links:

	* Arm64: <https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms>
	* x86: <https://developer.apple.com/documentation/xcode/writing-64-bit-intel-code-for-apple-platforms>

	### Microsoft

	Microsoft's x86-64 ABI is defined at <https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions>.
	There are a few different x86-32 conventions:

	* Cdecl (default): <https://learn.microsoft.com/en-us/cpp/cpp/cdecl>
	* Stdcall: <https://learn.microsoft.com/en-us/cpp/cpp/stdcall>
	* Fastcall: <https://learn.microsoft.com/en-us/cpp/cpp/fastcall>
	* Thiscall: <https://en.wikipedia.org/wiki/X86_calling_conventions#thiscall>

	As well as a few that aren't supported by Rust (`__clrcall`, `__vectorcall`, `__preserve_none`).

	Aarch64 targets generally use the AAPCS64 calling convention. There are some exceptions listed at
	<https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170>.

	Register mappings for arm64ec are documented at
	<https://learn.microsoft.com/en-us/cpp/build/arm64ec-windows-abi-conventions?view=msvc-170>.
	<http://www.emulators.com/docs/abc_arm64ec_explained.htm> does a great job of explaining more about
	how this works.

	#### Wasm

	The way that C types are broken down into Wasm types is described at
	<https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md>.

	### Additional Resources for Platform Specifics

	The following links aggregate more resources

	* Links to other resources such as ELF and DWARF: <https://refspecs.linuxfoundation.org/>
	* Links to a number of standards including ISAs <https://llvm.org/docs/CompilerWriterInfo.html>
	* More about System V ABIs, especially x86: <https://wiki.osdev.org/System_V_ABI>