RTEMS 4.9.2 On-Line Library

Target Dependent Files Board Support Package Structure

BSP and Device Driver Development Guide

2.7: Board Support Package Structure

The BSPs are all under the c/src/lib/libbsp directory. Below this directory, there is a subdirectory for each CPU family. Each BSP is found under the subdirectory for the appropriate processor family (m68k, powerpc, etc.). In addition, there is source code available which may be shared across all BSPs regardless of the CPU family or just across BSPs within a single CPU family. This results in a BSP using the following directories:

c/src/lib/libbsp/shared
c/src/lib/libbsp/CPU/shared
c/src/lib/libbsp/CPU/BSP

Under each BSP specific directory, there is a collection of subdirectories. For commonly provided functionality, the BSPs follow a convention on subdirectory naming. The following list describes the commonly found subdirectories under each BSP.

console: is technically the serial driver for the BSP rather than just a console driver, it deals with the board UARTs (i.e. serial devices).
clock: support for the clock tick -- a regular time basis to the kernel.
timer: support of timer devices.
rtc or tod: support for the hardware real-time clock.
nvmem: support for non-volatile memory such as EEPROM or Flash.
network: the Ethernet driver.
shmsupp: support of shared memory driver MPCI layer in a multiprocessor system,
include: include files for this BSP.
gnatsupp: BSP specific support for the GNU Ada run-time. Each BSP that wishes to have the possibility to map faults or exceptions into Ada language exceptions or hardware interrupts into Ada interrupt tasks must provide this support.

There may be other directories in the BSP tree and the name should be indicative of the functionality of the code within that directory.

The build order of the BSP is determined by the Makefile structure. This structure is discussed in more detail in the Makefiles chapter.

NOTE: This manual refers to the gen68340 BSP for numerous concrete examples. You should have a copy of the gen68340 BSP available while reading this piece of documentation. This BSP is located in the following directory:

c/src/lib/libbsp/m68k/gen68340

Later in this document, the $BSP340_ROOT label will be used to refer to this directory.

BSP and Device Driver Development Guide