ARM BSPs (Windows Embedded Compact 7)

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ARM Architecture Support

·         ARMv4i support has been removed and has been replaced by ARMv5 as the earliest ARM architecture supported by Windows Embedded Compact 7. 

·         ARMv6 and ARMv7 are supported.

·         Each of the Chelan BSPs is now enabled for the ARM architecture associated with the BSP.

What optimizations do I get with each variant?

·         ARMv5 is the same as the old ARMv4i, except some v5 instructions may be generated by the compiler. 

·         Thumb instructions are permitted and the OS code can be called via a 32-bit branch from THUMB code.  However, the default builds do not use thumb instructions by default. 

·         ARMv5 does not use vector floating point by default (it uses emulation).  If you have  a v5 CPU that has a VFP you should use the OEM FP replacement library to enable that functionality.

·         ARMv6 and ARMv7 use VFP inline by default (v2 and v3, respectively).  NEON (v7 feature) is auto-detected by some of the multimedia code, but there are no libraries available for generic NEON use.  NEON assembly language instructions are supported by the assembler.

·         ARMv6 has additional instructions over ARMv5, and ARMv7 has additional instructions over ARMv6.

Which ARM BSPs are supported with which ARM version?

Platform                                                  ARM Version

Freescale i.MX27                                   ARMv5

Freescale i.MX31                                   ARMv6

NEC NE1TB                                             ARMv6 (Multiprocessor CPU)

Samsung SMDK6410                            ARMv6

Texas Instruments 3530 EVM2          ARMv7