Example Project for GCC ARM

This example is for Cortex M series, but can be adopted for other architectures.



  1. Make sure you have gcc-arm-none-eabi installed.
  2. Modify the Makefile.common:
    • Use correct toolchain path TOOLCHAIN.
    • Use correct architecture 'ARCHFLAGS'. See GCC ARM Options -mcpu=name.
    • Confirm memory map in linker.ld matches your flash/ram or comment out SRC_LD = -T./linker.ld in Makefile.common.
  3. Use make to build the static library (libwolfssl.a), wolfCrypt test/benchmark and wolfSSL TLS client targets as .elf and .hex in /Build.

Building for Raspberry Pi

Example Makefile.common changes for Raspberry Pi with Cortex-A53:

  1. In Makefile.common change ARCHFLAGS to -mcpu=cortex-a53 -mthumb.
  2. Comment out SRC_LD, since custom memory map is not applicable.
  3. Clear TOOLCHAIN, so it will use default gcc. Set TOOLCHAIN =
  4. Comment out LDFLAGS += --specs=nano.specs and LDFLAGS += --specs=nosys.specs to nosys and nano.

Note: To comment out a line in a Makefile use place # in front of line.

Building for FIPS

  1. Request evaluation from wolfSSL by emailing fips@.nosp@m.wolf.nosp@m.ss.co.nosp@m.m.
  2. Modify user_settings.h so section for HAVE_FIPS is enabled.
  3. Use make.
  4. Run the wolfCrypt test ./Build/WolfCryptTest.elf to generate the FIPS boundary HASH


$ Crypt Test
error test passed!
base64 test passed!
base16 test passed!
asn test passed!
in my Fips callback, ok = 0, err = -203
message = In Core Integrity check FIPS error
hash = F607C7B983D1D283590448A56381DE460F1E83CB02584F4D77B7F2C583A8F5CD
In core integrity hash check failure, copy above hash
into verifyCore[] in fips_test.c and rebuild
SHA test failed!
error = -1802
Crypt Test: Return code -1
  1. Update the ../../wolfcrypt/src/fips_test.c array static const char verifyCore[] = {} with the correct core hash check.
  2. Build again using make.
  3. Run the wolfCrypt test.

Building with configure

The configure script in the main project directory can perform a cross-compile build with the the gcc-arm-none-eabi tools. Assuming the tools are installed in your executable path:

$ ./configure \
--host=arm-non-eabi \
CC=arm-none-eabi-gcc \
AR=arm-none-eabi-ar \
STRIP=arm-none-eabi-strip \
RANLIB=arm-none-eabi-ranlib \
--prefix=/path/to/build/wolfssl-arm \
CFLAGS="-march=armv8-a --specs=nosys.specs \
--disable-filesystem --enable-fastmath \
$ make
$ make install

If you are building for a 32-bit architecture, add -DTIME_T_NOT_64BIT to the list of CFLAGS.

Example Build Output

make clean && make
text data bss dec hex filename
50076 2508 44 52628 cd94 ./Build/WolfCryptTest.elf
text data bss dec hex filename
39155 2508 60 41723 a2fb ./Build/WolfCryptBench.elf
text data bss dec hex filename
70368 464 36 70868 114d4 ./Build/WolfSSLClient.elf

Performance Tuning Options

These settings are located in Header/user_settings.h.