propose new coding style based on Linux indentation
apply new coding style to each C file except external source
user: unify the licensing terms about L4/pistachio
apply appropriate CFLAGS while generating symmap

When floating-point is enabled with GNU Tools for ARM Embedded
Processors [*], we got the following error:

  arm-none-eabi-ld: error: build/discoveryf4/f9.elf uses VFP register
  arguments, build/discoveryf4/f9.symmap.o does not

It results from unmatched compilation options while generating symmap.

[*] https://launchpad.net/gcc-arm-embedded
Fix a typo: theak to tweak in in kernel/Kconfig
Merge remote-tracking branch 'upstream/master'
Merge pull request #63 from zzz0072/master

kernel: fix typo in Kconfig
mk: remove -Wdeclaration-after-statement complie flag in mk/toolchain.mk

Done tests:
1. Clean build ok
2. Burn image and boot ok
Merge pull request #64 from zzz0072/master

mk: remove -Wdeclaration-after-statement complie flag in mk/toolchain.mk
README: add verified version of GNU Tools for ARM Embedded
Documentation: tweak coding style slightly
make USART pin assignment configurable

Fixes #62

In preparation of new boards support other than STM32F4 Discovery, it is
necessary to make the USART pin assignment configurable. At present, both
USART4 (default) and USART2 of STM32F4DISCOVERY are supported depending on
Kconfig results.
board: bump copyright date accordingly
Avoid unexpected linker messages "Conflicting CPU architectures 13/0"

Fixes #61

The root cause of the issue is that the linker is assuming the wrong
defaults for an object which does not have a .ARM.attributes section.

We can remove all ".ARM.attributes " before linking to avoid this noise.
Please reference
http://permalink.gmane.org/gmane.comp.gnu.binutils/54317
Merge pull request #68 from georgekang/master

avoid unexpected linker message "Conflicting CPU architectures 13/0"
Add Build System Internals of F9 Microkernel document
Merge pull request #70 from zzz0072/master

Documentation: add build system Internals
add support USART1 & USART6 in usart_baud(), because USART1 & USART6 clock source is APB2/PCLK2, others USARTx is APB1/PCLK1

current the kernel setting STM32F4xx CPU Clock/AHB (HCLK) run in 168MHz
PCLK1: 42MHz, PCLK2: 84MHz

reference: Table 2. STM32F4xx register boundary RM0090 Reference manual
(DM00031020.pdf, http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf)
add DBGPORT_USE_USART1 options
Should pick up it for STM32F429I discovery board
Merge pull request #69 from KunYi/master

platform: add USART1 configurations for STM32F4x