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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-02-23 21:29:42 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-02-23 21:29:42 +0000 |
commit | 6537ccc38c1dbb7261b037bf3919bbe6e6c89bf7 (patch) | |
tree | feeb06bdb58e93a0722363f90b2b7dda8f86be4e /nuttx/configs/stm3240g-eval/README.txt | |
parent | ea61dba2159dde7b53fda2bcabdd172a081687ef (diff) | |
download | px4-nuttx-6537ccc38c1dbb7261b037bf3919bbe6e6c89bf7.tar.gz px4-nuttx-6537ccc38c1dbb7261b037bf3919bbe6e6c89bf7.tar.bz2 px4-nuttx-6537ccc38c1dbb7261b037bf3919bbe6e6c89bf7.zip |
Enable STM32 F4 hardware floating point with the Atollic toolchain
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4418 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/configs/stm3240g-eval/README.txt')
-rwxr-xr-x | nuttx/configs/stm3240g-eval/README.txt | 75 |
1 files changed, 68 insertions, 7 deletions
diff --git a/nuttx/configs/stm3240g-eval/README.txt b/nuttx/configs/stm3240g-eval/README.txt index 3e47d9db8..2c7c09bdf 100755 --- a/nuttx/configs/stm3240g-eval/README.txt +++ b/nuttx/configs/stm3240g-eval/README.txt @@ -115,6 +115,28 @@ GNU Toolchain Options CONFIG_MOTOROLA_SREC=n CONFIG_RAW_BINARY=n + Another problem that I had with the Atollic toolchain is that the provide a gcc.exe + and g++.exe in the same bin/ file as their ARM binaries. If the Atollic bin/ path + appears in your PATH variable before /usr/bin, then you will get the wrong gcc + when you try to build host executables. This will cause to strange, uninterpretable + errors build some host binaries in tools/ when you first make. Here is my + workaround kludge. + + 1. Edit the setenv.sh to put the Atollic toolchain at the beginning of the PATH + 2. Source the setenv.sh file: . ./setenv.sh. A side effect of this is that it + will set an environment variable called PATH_ORIG. + 3. Then go back to the original patch: export PATH=$PATH_ORIG + 4. Then make. The make will build all of the host executable but will fail + when it gets to the first ARM binary. + 5. Then source setenv.sh again: . ./setenv.sh. That will correct the PATH + again. When you do make again, the host executables are already made and + now the correct PATH is in place for the ARM build. + + Also, the Atollic toolchain is the only toolchain that has built-in support for + the FPU in these configurations. If you plan to use the Cortex-M4 FPU, you will + need to use the Atollic toolchain for now. See the FPU section below for more + information. + NOTE 3: The devkitARM toolchain includes a version of MSYS make. Make sure that the paths to Cygwin's /bin and /usr/bin directories appear BEFORE the devkitARM path or will get the wrong version of make. @@ -354,15 +376,54 @@ There are two version of the FPU support built into the STM32 port. CFLAGS ------ -To used the FPU, you will also have to modify the CFLAGS to enable compiler -support for the ARMv7-M FPU. As of this writing, there are not many GCC -toolchains that will support the ARMv7-M FPU. +Only the Atollic toolchain has built-in support for the Cortex-M4 FPU. You will see +the following lines in each Make.defs file: + + ifeq ($(CONFIG_STM32_ATOLLIC),y) + # Atollic toolchain under Windows + ... + ifeq ($(CONFIG_ARCH_FPU),y) + ARCHCPUFLAGS = -mcpu=cortex-m4 -mthumb -march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=hard + else + ARCHCPUFLAGS = -mcpu=cortex-m3 -mthumb -mfloat-abi=soft + endif + endif + +If you are using a toolchain other than the Atollic toolchain, then to use the FPU +you will also have to modify the CFLAGS to enable compiler support for the ARMv7-M +FPU. As of this writing, there are not many GCC toolchains that will support the +ARMv7-M FPU. + +As a minimum you will need to add CFLAG options to (1) enable hardware floating point +code generation, and to (2) select the FPU implementation. You might try the same +options as used with the Atollic toolchain in the Make.defs file: + + ARCHCPUFLAGS = -mcpu=cortex-m4 -mthumb -march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=hard + +Configuration Changes +--------------------- + +Below are all of the configuration changes that I had to make to configs/stm3240g-eval/nsh2 +in order to successfully build NuttX using the Atollic toolchain WITH FPU support: + + -CONFIG_ARCH_FPU=y : Enable FPU support + +CONFIG_ARCH_FPU=n + + -CONFIG_STM32_CODESOURCERYW=n : Disable the CodeSourcery toolchain + +CONFIG_STM32_CODESOURCERYW=y + + -CONFIG_STM32_ATOLLIC=y : Enable the Atollic toolchain + +CONFIG_STM32_ATOLLIC=n + + -CONFIG_INTELHEX_BINARY=n : Suppress generation FLASH download formats + +CONFIG_INTELHEX_BINARY=y -As a minimum, you will need to CFLAG options to (1) enable hardware floating -point code generation, and to (2) select the FPU implementation. You might -try something like the following in the Make.defs file: + -CONFIG_HAVE_CXX=n : Suppress generation of C++ code + +CONFIG_HAVE_CXX=y -ARCHCPUFLAGS = -mcpu=cortex-m4 -mthumb -march=armv7e-m -mfpu=fpv4-sp-d16 -mfloat-abi=hard +See the section above on Toolchains, NOTE 2, for explanations for some of +the configuration settings. Some of the usual settings are just not supported +by the "Lite" version of the Atollic toolchain. STM3240G-EVAL-specific Configuration Options ============================================ |