ARM Cross Compiler Brief introduction

Arm Cross compiler brief introduction One, cross compiler naming rules:

The naming convention for the cross-compilation toolchain is: Arch [-vendor] [-os] [-(GNU) Eabi] Arch -architecture, such as Arm,mips vendor -toolchain provider OS -target operation System Eabi -Embedded Application Binary interface (Embedded application binary Interface)

Depending on whether the operating system is supported or not, ARM GCC can be divided into supported and unsupported operating systems, such as
-Arm-none-eabi: This is not an operating system, and naturally it is impossible to support functions that are closely related to the operating system, such as fork (2). He uses newlib, a C library dedicated to embedded systems.
-Arm-none-linux-eabi: For Linux, using GLIBC, example 1. ARM-NONE-EABI-GCC

(Arm architecture,no Vendor,not target an operating system,complies with the arm EABI)
Bare-metal systems for compiling the ARM architecture (including boot, kernel for ARM Linux, not for compiled Linux applications application), generally suitable for ARM7, cortex-m, and cortex-r cores, so it is not supported by those operating systems A closely related function, such as fork (2), uses newlib, a C library dedicated to embedded systems. 2. ARM-NONE-LINUX-GNUEABI-GCC

(ARM architecture, no vendor, creates binaries that run on the Linux operating system, and uses the GNU EABI)

Mainly used in the ARM architecture based Linux system, can be used to compile the arm architecture of U-boot, Linux kernel, Linux applications and so on. Arm-none-linux-gnueabi is based on GCC and uses the GLIBC library, which has been optimized by Codesourcery company to launch the compiler. The Arm-none-linux-gnueabi-xxx cross-compilation tool has excellent floating-point operations. General ARM9, ARM11, cortex-a kernel, with Linux operating system will be used. 3. ARM-EABI-GCC

Android ARM compiler. 4. ARMCC

ARM's compiled tools, like Arm-none-eabi, can compile bare-metal programs (u-boot, kernel), but not Linux applications. ARMCC generally with ARM development tools, compilers in Keil MDK, ADS, RVDS, and DS-5 are ARMCC, so ARMCC compilers are charged. 5. ARM-NONE-UCLINUXEABI-GCC and ARM-NONE-SYMBIANELF-GCC

Arm-none-uclinuxeabi for Uclinux, using GLIBC.

arm-none-symbianelf used for Symbian, and did not know what the C library was. third, ABI and EABI

ABI: Binary Application Interface (application binary Interface (ABI) for the ARM Architecture). In computers, applying a binary interface describes a low-level interface between an application (or other type) and an operating system or another application.

EABI: Embedded ABI. Embedded application binary interfaces specify standard conventions for file formats, data types, register usage, stacked organization optimizations, and parameters in an embedded software. Developers using their own assembly language can also use EABI as an interface to the assembly language generated by the compatible compiler.

The main difference between the two is that the ABI is on the computer, Eabi is embedded on the platform (such as arm,mips, etc.). iv. ARM-LINUX-GNUEABI-GCC and ARM-LINUX-GNUEABIHF-GCC

The two cross compilers are suitable for Armel and ARMHF two different architectures, and Armel and ARMHF have different strategies for floating-point operations (with the FPU arm to support both floating-point arithmetic strategies).

In fact, these two cross compilers are only GCC's option-mfloat-abi the default values are different. GCC options-mfloat-abi have three values soft, SOFTFP, hard (both of which require the FPU floating point unit in arm, soft and the latter are compatible, but SOFTFP and hard two modes are incompatible):

Soft : Use the software mode instead of the FPU for floating point calculations, even if the FPU floating point unit is not used.
SOFTFP : The default value used by the Armel schema (the corresponding compiler is ARM-LINUX-GNUEABI-GCC), calculated with the FPU, but the pass parameter is transmitted by ordinary registers, so when the interrupt, only need to save the ordinary register , the interrupt load is small, but the parameters need to be converted to floating-point recalculation.
Hard : The default value used by the ARMHF schema (corresponding compiler ARM-LINUX-GNUEABIHF-GCC) is calculated with the FPU, and the pass parameter is also transmitted using the floating-point register in the FPU, eliminating the need for conversion, the best performance, But the interruption load is high. references arm cross compiler Gnueabi, None-eabi, Arm-eabi, GNUEABIHF, Gnueabi differences: http://www.veryarm.com/296.html Cross-compiler Arm-linux-gnueabi and ARM-LINUX-GNUEABIHF differences: http://www.cnblogs.com/xiaotlili/p/3306100.html The difference between Arm-none-linux-gnueabi,arm-none-eabi and Arm-eabi: http://blog.csdn.net/mantis_1984/article/details/21049273 What ' s the difference between arm-linux-/arm-none-linux-gnueabi-/arm-fsl-linux-gnueabi-in ltib?https:// community.freescale.com/thread/313490