nuttx/boards/risc-v/litex/arty_a7
chao.an b88561299b make/expression: improving up asm/C/C++ compile times
In the current compilation environment, the recursive assignment(=) for compile
flags will be delayed until every file is actually need to be compile.

For example:
--------------------------------------------------------------------------------
arch/arm/src/Makefile:

INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)chip}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)common}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)$(ARCH_SUBDIR)}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(TOPDIR)$(DELIM)sched}

CPPFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CXXFLAGS += $(INCLUDES) $(EXTRAFLAGS)
AFLAGS += $(INCLUDES) $(EXTRAFLAGS)
--------------------------------------------------------------------------------

All compilation options will be included recursively,
which will be delayed until the compilation options are actually used:

tools/Config.mk:

--------------------------------------------------------------------------------
define COMPILE
  @echo "CC: $1"
  $(Q) $(CC) -c $(CFLAGS) $($(strip $1)_CFLAGS) $1 -o $2
endef
--------------------------------------------------------------------------------

All compile flags to be reexecuted $(INCDIR) as long as one file needs to be compiled,
but in fact, the compilation options have not changed in the current directory.

So the we recommand to change the syntax of assignment
From
    Recursive (=)
To
    Simple    (:=)

In this way, we can ensure that all compilation options are expanded only once and reducing repeated works.

Signed-off-by: chao.an <anchao@xiaomi.com>
2020-11-02 07:53:53 -08:00
..
configs/nsh libc/stdio: Allocate file_struct dynamically 2020-09-11 17:58:17 +08:00
include Add support for Litex VexRiscV. 2020-03-21 06:01:56 +00:00
scripts make/expression: improving up asm/C/C++ compile times 2020-11-02 07:53:53 -08:00
src build: Move .config check to the top Makefile 2020-05-20 17:57:34 +01:00
Kconfig Add support for Litex VexRiscV. 2020-03-21 06:01:56 +00:00
README.txt Add support for Litex VexRiscV. 2020-03-21 06:01:56 +00:00

1. Download and install toolchain

  $ curl https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14.tar.gz

2. Follow instruction on https://github.com/enjoy-digital/litex to build the vexriscv softcore fpga gateware
   and flash to arty_a7 board

3. Configure and build NuttX

  $ mkdir ./nuttx; cd ./nuttx
  $ git clone https://bitbucket.org/nuttx/nuttx.git
  $ git clone https://bitbucket.org/nuttx/apps.git
  $ cd nuttx
  $ make distclean
  $ ./tools/configure.sh arty_a7:nsh
  $ make V=1

4. Setup tftp server on your laptop, copy nuttx.bin to your tftpboot directory and change its name to boot.bin

5. Setup the wire connection(uart and tftp) between your board and laptop

6. Run  $ minicom -b 1000000 /dev/ttyUSB1 (the default baudrate on litex vexriscv is 1e6)
   when you see the bios prompt "litex>", type "netboot" and enter soon comes the nsh prompt

7. TODO

  Support GPIO/SPI/I2C/RTC/WDT/PWM
  Support RISC-V User mode