1.12 ARM architecture v7-A
ARMv7-A is a variant of the ARMv7 architecture targeted at the application profile.
The following table shows useful command-line options.
Table 1-7 Useful command-line options for ARMv7-A
|ARMv7 with Thumb instructions only (no ARM
instructions), and without hardware dividea
|ARMv7 application profile supporting virtual
MMU-based memory systems, with ARM, Thumb, and ThumbEE instructions, NEON™ support, and 32-bit SIMD support
a specific ARM processor. For example:
ARMv7 with ARM and Thumb instructions, hardware VFP, NEON support,
and 32-bit SIMD support.
Key features for ARMv7-A:
The data alignment behavior supported by the ARM architecture
is significantly different between ARMv4 and ARMv7. An ARMv7 implementation
must support unaligned data accesses. You can control the alignment
requirements of load and store instructions by using the
in the CP15 register c1.
ARMv7 architectures do not support pre-ARMv6 alignment.
You can produce either little-endian or big-endian code using
the compiler command-line options
ARMv7-A supports the following endian modes:
big-endian format used by ARMv6 and ARMv7.
ARMv7 does not support the legacy BE-32 mode. If you have legacy code for ARMv7
processors that contain instructions with a big-endian byte order, then you must perform
byte order reversal.