AVR

From Free Pascal wiki

English (en)

Warning-icon.png

Warning: The FPC-AVR port is experimental and might be broken from time to time. If this is the case, please fill a bug report

FPC-AVR is the Free Pascal Compiler port for the AVR microcontroller. It uses the GCC AVR tool chain and will be compatible with GCC regarding calling conventions etc.

For instructions on how to program AVR's with Free Pascal, see the article AVR Programming.

Implementation details

FPC considers AVR to be a 16 bit CPU. So the type TRegister actually describes a register pair with the second register implicitly named.

Building cross-compiler

There are some requirements, you should know about:

  • You should use the latest Free Pascal sources as there is the most recent support for more controllers.
  • Binutils for avr target
    • Microchip (previously Atmel) provides bintuils binaries for Linux, macOS (Darwin) and Windows.
      Download using the appropriate link for your operating system]
    • On a Linux host, you may either install binutils for the avr target from your distribution or use also the binaries provided by Microchip (previously Atmel).
    • You may also use the binutils distributed with the Arduino IDE; on Windows they are installed to eg C:\Program Files (x86)\Arduino\hardware\tools\avr\avr\bin
    • Keep in mind that the Free Pascal Compiler will search for eg avr-embedded-as. So you must either rename the binary files, create symlinks (on Linux only) or adjust command line switch -XP<prefix> for FPC.
    • You may need to set FPC's command line switch -FD<directory with binutils>
  • Latest stable Free Pascal Compiler.

Then you can build your cross compiler. Please choose SUBARCH according to your Arduino board / AVR microcontroller.

make buildbase installbase CPU_TARGET=avr OS_TARGET=embedded SUBARCH=avr5 CROSSINSTALL=1 INSTALL_PREFIX=~/fpc NOGDB=1 PP=/usr/bin/fpc CROSSBINDIR=/usr/avr/bin

You may also set the binutils prefix for this (equivalent to the -XP switch)

make buildbase installbase CPU_TARGET=avr OS_TARGET=embedded SUBARCH=avr5 CROSSINSTALL=1 INSTALL_PREFIX=~/fpc NOGDB=1 PP=/usr/bin/fpc CROSSBINDIR=/usr/avr/bin  BINUTILSPREFIX=avr-

Subarchitecture

The operating system target embedded requires that you specify a subarchitectures when building a cross compiler. The subarchitectures are compatible with the ones used by GCC.

Resources