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Diffstat (limited to 'c/src/lib/libbsp/bare/README')
| -rw-r--r-- | c/src/lib/libbsp/bare/README | 122 |
1 files changed, 77 insertions, 45 deletions
diff --git a/c/src/lib/libbsp/bare/README b/c/src/lib/libbsp/bare/README index 773e6aa2c0..11362253b0 100644 --- a/c/src/lib/libbsp/bare/README +++ b/c/src/lib/libbsp/bare/README @@ -13,6 +13,8 @@ # # +# Overview +# ~~~~~~~~ # This board support package is not a board support package at all, but # a means to build the RTEMS kernel without using a specific BSP. # @@ -37,49 +39,79 @@ # # I fit all the above. # +# Issues +# ~~~~~~ +# I do not consider the bare BSP as a starting point for RTEMS. The +# BSP code integrated into the RTEMS build tree has the advantage of +# building all the test and sample code. The sample and test code is +# important for validatation of your tools, and getting your BSP +# working correctly. +# +# Once you gain experience with RTEM and your application matures the +# need to break the BSP code out from the kernel becomes important. It +# is at this point in time that the bare BSP becomes useful. +# +# Once free you are able to upgrade without the worry of makefile or +# build tree changes which can break your BSP. +# +# How To Configure +# ~~~~~~~~~~~~~~~~ +# RTEMS requires you to select a BSP inorder to build the kernel. +# If you take a close look at a BSP which is closest to your +# needs you will find somewhere the CPU model and CPU compile +# flags are specified. This is the only piece of information +# required by the kernel inorder for it to build. +# +# This highlights the clean design of the kernel and its +# independence from the particulars of target hardware. +# +# The CPU model is the RTEMS model and usually tries to match with +# the GCC model. There are variations on some processors. If you are +# unsure please ask on the RTEMS list. Someone will know (I hope). +# +# The CPU flags allow you to select specific operating modes for +# GCC. For example the PowerPC has specific flags to control various +# cache resouces. Another example is the 68000 family of embedded +# processor do not have FPU hardware and require software emulation. +# +# An example configuration command line is: +# +# ../rtems-4.0/configure --target=m68k-rtems \ +# --prefix=/ods/egcs/test \ +# --enable-cxx \ +# --enable-gmake-print-directory \ +# --disable-tests \ +# --disable-posix \ +# --enable-ka9q \ +# --enable-bare-cpu-cflags=-mcpu32 \ +# --enable-bare-cpu-model=mcpu32 \ +# --enable-rtemsbsp=bare +# +# Building RTEMS +# ~~~~~~~~~~~~~~ +# You are required to do nothing special here. Just follow the documented +# steps. The samples are built but no linking occurs. The link command +# is stubbed out to produce a Unix shell script. +# +# After installation you will find a directory called 'bare'. The nature +# of the RTEMS build system means the bare BSP will only install into the +# the bare directory under the specifed configuration prefix. +# +# I therefore suggest you move the directory to another name. This allows +# you to make and install another bare BSP for a different variant of +# CPU without over writing the last installed variant. +# +# I have provided a script file I use to configure and build RTEMS +# from the arcihve. Take a copy and use it if you find it useful. +# +# Creating an Application. +# ~~~~~~~~~~~~~~~~~~~~~~~~ +# This is something which is usually specific to your local environment. +# The bare BSP does not lock you into any specific makefile or build +# system. A couple of suggestions are: +# +# o Get the sample bare BSP application, or +# o Watch RTEMS build a BSP which is closest to yours and copy +# the command lines used. +# -BSP NAME: bare -BOARD: not applicable -BUS: not applicable -CPU FAMILY: all -COPROCESSORS: not applicable -MODE: not applicable - -DEBUG MONITOR: not applicable - -PERIPHERALS -=========== -not applicable - -DRIVER INFORMATION -================== -not applicable - -STDIO -===== -not applicable - -NOTES -===== - -Board description ------------------ -not applicable - -Host System ------------ -Linux (RedHat 4.0/5.0) -egcs-1.0.2 -binutils-2.8.1, with rtems patches -newlib-1.8.0, with rtems patches - -Verification -------------------------------- -Single processor tests: not applicable -Multi-processort tests: not applicable -Timing tests: - not applicable - -Porting -------- - not applicable |