F.A.Q (Frequently Asked Questions):

What is Toolchain?

In software, a toolchain is the set of programming tools that are used to create a product (typically another computer program or system of programs). The tools may be used in a chain, so that the output of each tool becomes the input for the next, but the term is used widely to refer to any set of linked development tools.
A simple software development toolchain consists of a compiler and linker to transform the source code into an executable program, libraries to provide interfaces to the operating system, and a debugger. A complex product such as a video game needs tools for preparing sound effects, music, textures, 3-dimensional models, and animations, and further tools for combining these resources into the finished product.

Source: http://en.wikipedia.org/wiki/Toolchain

What is SaberMod?

SaberMod is a AOSP based ROM with some extra features added in and mostly from CyanogenMod. SaberMod started out pure AOSP when android 4.2.1 launched. Originally it was pure AOSP with a few extra features I ported over from CyanogeMod and linaro optimizations. Then I rebased everything off of rasbeanjelly because I liked many features found in rasbean. Since then I've modified a lot of the code so not much of it is rasbeanjelly based anymore. But you will still find some commonly used features found in rasbeanjelly. SaberMod is not a rasbeanjelly or CM clone, or KANG. Custom kernels are included for certain devices when available. These are personal builds we make for ourselves and originally became very popular in the nexus 7 forums. Features are very rarely added, and are built to SaberMod's team members liking. Currently there are two members of SaberMod working on this project. Myself and @jarjar124. Please understand our time is limited and we are only two people who have lives, and do not have 25-50 members like CyanogenMod to add things. And our goal is not to add a bunch of features that bloat the system of the ROM.

Source: http://forum.xda-developers.com/show....php?t=2158698

What is Linaro?

Linaro is the place where engineers from the world's leading technology companies define the future of Linux on ARM. The company is a not-for-profit engineering organization with over 120 engineers working on consolidating and optimizing open source software for the ARM architecture, including the GCC toolchain, the Linux kernel, ARM power management, graphics and multimedia interfaces.

Source: http://www.linaro.org/linux-on-arm/

About GCC main compiler cflags:

  • O1
    Optimize. Optimizing compilation takes somewhat more time, and a lot more memory for a large function. With -O, the compiler tries to reduce code size and execution time, without performing any optimizations that take a great deal of compilation time.
  • O2
    Optimize even more. GCC performs nearly all supported optimizations that do not involve a space-speed tradeoff. As compared to -O, this option increases both compilation time and the performance of the generated code. -O2 turns on all optimization flags specified by -O.
  • Os
    Optimize for size. -Os enables all -O2 optimizations that do not typically increase code size. It also performs further optimizations designed to reduce code size.
  • O3
    Optimize yet more. -O3 turns on all optimizations specified by -O2 and also turns on the -finline-functions, -funswitch-loops, -fpredictive-commoning, -fgcse-after-reload, -ftree-loop-vectorize, -ftree-slp-vectorize, -fvect-cost-model, -ftree-partial-pre and -fipa-cp-clone options.