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diff --git a/Documentation/RFC/config.tex b/Documentation/RFC/config.tex new file mode 100644 index 0000000000..6d6c433025 --- /dev/null +++ b/Documentation/RFC/config.tex @@ -0,0 +1,291 @@ + New config language for LinuxBIOS + +\begin{abstract} +We describe the new configuration language for LinuxBIOS. +\end{abstract} + +\section{Scope} +This document defines the new configuration language for LinuxBIOS. + +\section{Goals} +The goals of the new language are these: +\begin{itemize} +\item Simplified Makefiles so people can see what is set +\item Move from the regular-expression-based language to something +a bit more comprehensible and flexible +\item make the specification easier for people to use and understand +\item allow unique register-set-specifiers for each chip +\item allow generic register-set-specifiers for each chip +\item generate static initialization code, as needed, for the +specifiers. +\end{itemize} + +\section{Language} +Here is the new language. It is very similar to the old one, differing +in only a few respects. It borrows heavily from Greg Watson's suggestions. + +I am presenting it in a pseudo-BNF in the hopes it will be easier. Things +in '' are keywords; things in ``'' are strings in the actual text. +\begin{verbatim} +#exprs are composed of factor or factor + factor etc. +expr ::= factor ( ``+'' factor | ``-'' factor | )* +#factors are term or term * term or term / term or ... +factor ::= term ( ``*'' term | ``/'' term | ... )* +# +unary-op ::= ``!'' ID +# term is a number, hexnumber, ID, unary-op, or a full-blown expression +term ::= NUM | XNUM | ID | unary-op | ``(`` expr ``)'' + +# Option command. Can be an expression or quote-string. +# Options are used in the config tool itself (in expressions and 'if') +# and are also passed to the C compiler when building linuxbios. +# It is an error to have two option commands in a file. +# It is an error to have an option command after the ID has been used +# in an expression (i.e. 'set after used' is an error) +option ::= 'option' ID '=' (``value'' | term) + +# Default command. The ID is set to this value if no option command +# is scanned. +# Multiple defaults for an ID will produce warning, but not errors. +# It is OK to scan a default command after use of an ID. +# Options always over-ride defaults. +default ::= 'default' ID '=' (``value'' | term) + +# the mainboard, southbridge, northbridge commands +# cause sourcing of Config.lb files as in the old config tool +# as parts are sourced, a device tree is built. The structure +# of the tree is determined by the structure of the components +# as they are specified. To attach a superio to a southbridge, for +# example, one would do this: +# southbridge acer/5432 +# superio nsc/123 +# end +# end +# the tool generates static initializers for this hierarchy. + +# add C code to the current component (motherboard, etc. ) +# to initialise the component-INDEPENDENT structure members +init ::= 'init' ``CODE'' + +# add C code to the current component (motherboard, etc. ) +# to initialise the component-DEPENDENT structure members +register ::= 'register' ``CODE'' + + +# mainboard command +# statements in this block will set variables controlling the mainboard, +# and will also place components (northbridge etc.) in the device tree +# under this mainboard +mainboard ::= 'mainboard' PATH (statements)* 'end' + +# standard linuxbios commands +southbridge ::= 'southbridge' PATH (statemnts)* 'end' +northbridge ::= 'northbridge' PATH (statemnts)* 'end' +superio ::= 'superio PATH (statemnts)* 'end' +cpu ::= 'cpu' PATH (statemnts)* 'end' +arch ::= 'arch' PATH (statemnts)* 'end' + +# files for building linuxbios +# include a file in crt0.S +mainboardinit ::= 'mainboardinit' PATH + +# object file +object ::= 'object' PATH +# driver objects are just built into the image in a different way +driver ::= 'driver' PATH + +# Use the Config.lb file in the PATH +dir ::= 'dir' PATH + +# add a file to the set of ldscript files +ldscript ::= 'ldscript' PATH + +# dependencies or actions for the makerule command +dep ::= 'dep' ``dependency-string'' +act ::= 'act' ``actions'' +depsacts ::= (dep | act)* +# set up a makerule +# +makerule ::= 'makerule' PATH depsacts + +#defines for use in makefiles only +# note usable in the config tool, not passed to cc +makedefine ::= 'makedefine' ``RAWTEXT'' + +# add an action to an existing make rule +addaction ::= 'addaction' PATH ``ACTION'' + +# statements +statement ::= + option + | default + | cpu + | arch + | northbridge + | southbridge + | superio + | object + | driver + | mainboardinit + | makerule + | makedefine + | addaction + | init + | register + | iif + | dir + | ldscript + +statements ::= (statement)* + +# target directory specification +target ::= 'target' PATH + +# and the whole thing +board ::= target (option)* mainboard + +\end{verbatim} + +\subsubsection{Command definitions} +\subsubsubsection{option} +\subsubsubsection{default} +\subsubsubsection{cpu} +\subsubsubsection{arch} +\subsubsubsection{northbridge} +\subsubsubsection{southbridge} +\subsubsubsection{superio} +\subsubsubsection{object} +\subsubsubsection{driver} +\subsubsubsection{mainboardinit} +\subsubsubsection{makerule} +\subsubsubsection{makedefine} +\subsubsubsection{addaction} +\subsubsubsection{init} +\subsubsubsection{register} +\subsubsubsection{iif} +\subsubsubsection{dir} +\subsubsubsection{ldscript} + + +A sample file: + +\begin{verbatim} +target x + +# over-ride the default rom size in the mainboard file +option CONFIG_ROM_SIZE=1024*1024 +mainboard amd/solo +end + +\end{verbatim} + +Sample mainboard file +\begin{verbatim} +# +### +### Set all of the defaults for an x86 architecture +### +arch i386 end +cpu k8 end +# +option CONFIG_DEBUG=1 +default CONFIG_USE_FALLBACK_IMAGE=1 +option A=(1+2) +option B=0xa +# +### +### Build our 16 bit and 32 bit linuxBIOS entry code +### +mainboardinit cpu/i386/entry16.inc +mainboardinit cpu/i386/entry32.inc +ldscript cpu/i386/entry16.lds +ldscript cpu/i386/entry32.lds +# +### +### Build our reset vector (This is where linuxBIOS is entered) +### +if CONFIG_USE_FALLBACK_IMAGE + mainboardinit cpu/i386/reset16.inc + ldscript cpu/i386/reset16.lds +else + mainboardinit cpu/i386/reset32.inc + ldscript cpu/i386/reset32.lds +end +. +. +. +if CONFIG_USE_FALLBACK_IMAGE mainboardinit arch/i386/lib/noop_failover.inc end +# +### +### Romcc output +### +#makerule ./failover.E dep "$(CONFIG_MAINBOARD)/failover.c" act "$(CPP) -I$(TOP)/src $(CPPFLAGS) $(CONFIG_MAINBOARD)/failover.c > ./failever.E" +#makerule ./failover.inc dep "./romcc ./failover.E" act "./romcc -O ./failover.E > failover.inc" +#mainboardinit ./failover.inc +makerule ./auto.E dep "$(CONFIG_MAINBOARD)/auto.c" act "$(CPP) -I$(TOP)/src -$(ROMCCPPFLAGS) $(CPPFLAGS) $(CONFIG_MAINBOARD)/auto.c > ./auto.E" +makerule ./auto.inc dep "./romcc ./auto.E" act "./romcc -O ./auto.E > auto.inc" +mainboardinit ./auto.inc +# +### +### Include the secondary Configuration files +### +northbridge amd/amdk8 +end +southbridge amd/amd8111 +end +#mainboardinit arch/i386/smp/secondary.inc +superio nsc/pc87360 + register "com1={1} com2={0} floppy=1 lpt=1 keyboard=1" +end +dir /pc80 +##dir /src/superio/winbond/w83627hf +cpu p5 end +cpu p6 end +cpu k7 end +cpu k8 end +# +### +### Build the objects we have code for in this directory. +### +##object mainboard.o +driver mainboard.o +object static_devices.o +if CONFIG_HAVE_MP_TABLE object mptable.o end +if CONFIG_HAVE_PIRQ_TABLE object irq_tables.o end +### Location of the DIMM EEPROMS on the SMBUS +### This is fixed into a narrow range by the DIMM package standard. +### +option SMBUS_MEM_DEVICE_START=(0xa << 3) +option SMBUS_MEM_DEVICE_END=(SMBUS_MEM_DEVICE_START +1) +option SMBUS_MEM_DEVICE_INC=1 +# +### The linuxBIOS bootloader. +### +option CONFIG_PAYLOAD_SIZE = (CONFIG_ROM_SECTION_SIZE - CONFIG_ROM_IMAGE_SIZE) +option CONFIG_ROM_PAYLOAD_START = (0xffffffff - CONFIG_ROM_SIZE + CONFIG_ROM_SECTION_OFFSET + 1) +# + +\end{verbatim} + +I've found the output of the new tool to be easier to +handle. Makefile.settings looks like this, for example: +\begin{verbatim} +TOP:=/home/rminnich/src/yapps2/freebios2 +TARGET_DIR:=x +export CONFIG_MAINBOARD:=/home/rminnich/src/yapps2/freebios2/src/mainboard/amd/solo +export CONFIG_ARCH:=i386 +export CONFIG_RAMBASE:=0x4000 +export CONFIG_ROM_IMAGE_SIZE:=65535 +export CONFIG_PAYLOAD_SIZE:=131073 +export CONFIG_MAX_CPUS:=1 +export CONFIG_HEAP_SIZE:=8192 +export CONFIG_STACK_SIZE:=8192 +export CONFIG_MEMORY_HOLE:=0 +export COREBOOT_VERSION:=1.1.0 +export CC:=$(CONFIG_CROSS_COMPILE)gcc + +\end{verbatim} + +In other words, instead of expressions, we see the values. It's easier to +deal with. + |