-#LyX 1.4.3 created this file. For more info see http://www.lyx.org/
+#LyX 1.4.5 created this file. For more info see http://www.lyx.org/
\lyxformat 245
\begin_document
\begin_header
\begin_layout Date
\size normal
-SDCC 2.7.4
+SDCC 2.8.0
\size footnotesize
\newline
\end_inset
- functions are casted to int unless explicitly casted
+ functions are casted to int unless explicitly casted and
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
+
+\end_inset
+
+
+\series default
+and
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+
+\end_inset
+
+
+\series default
+ command line option are not defined
\begin_inset Marginal
status collapsed
\family default
\newline
- will push a as an int and as a char resp.
+ will push a as an int and as a char resp if
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
+
+\end_inset
+
+
+\series default
+and
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+
+\end_inset
+
+
+\series default
+ command line options are not defined,
+\newline
+ will push a as two ints if
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
+
+\end_inset
+
+
+\series default
+or
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+
+\end_inset
+
+
+\series default
+ command line option is defined.
\end_layout
\begin_layout Itemize
\begin_layout List
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-no-std-crt0
+\series default
+
+\begin_inset LatexCommand \index{Z80!Options!-\/-no-std-crt0}
+
+\end_inset
+
+ When linking, skip the standard crt0.o object file.
+ You must provide your own crt0.o for your system when linking.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
\series bold
-bo
\series default
\begin_layout Standard
\begin_inset Tabular
-<lyxtabular version="3" rows="11" columns="2">
+<lyxtabular version="3" rows="15" columns="2">
<features>
<column alignment="left" valignment="top" leftline="true" width="3in">
<column alignment="left" valignment="top" leftline="true" rightline="true" width="3in">
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
is used
\end_layout
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+SDCC_REVISION
+\begin_inset LatexCommand \index{SDCC\_REVISION}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Always defined.
+ SDCC svn revision number
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+SDCC_PARMS_IN_BANK1
+\begin_inset LatexCommand \index{SDCC\_PARMS\_IN\_BANK1}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+when
+\emph on
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-parms-in-bank1
+\emph default
+ is used
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+SDCC_FLOAT_REENT
+\begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+when
+\emph on
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-float-reent
+\emph default
+ is used
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+SDCC_INT_LONG_REENT
+\begin_inset LatexCommand \index{SDCC\_INT\_LONG\_REENT}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+when
+\emph on
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-int-long-reent
+\emph default
+ is used
+\end_layout
+
\end_inset
</cell>
</row>
These are currently not used for the MCS51 port.
If you absolutely need them you can fall back to inline assembly or submit
a patch to SDCC.
+\end_layout
+
+\begin_layout Subsection
+Bankswitching
+\end_layout
+
+\begin_layout Standard
+Bankswitching
+\begin_inset LatexCommand \index{Bankswitching}
+
+\end_inset
+
+ (a.k.a.
+ code banking
+\begin_inset LatexCommand \index{code banking}
+
+\end_inset
+
+) is a technique to increase the code space above the 64k limit of the 8051.
+\end_layout
+
+\begin_layout Subsubsection
+Hardware
+\end_layout
+
+\begin_layout Standard
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="4">
+<features>
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell multicolumn="1" alignment="center" valignment="top" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+8000-FFFF
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+bank1
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+bank2
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+bank3
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell multicolumn="1" alignment="center" valignment="top" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0000-7FFF
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+common
+\end_layout
+
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+<cell multicolumn="2" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row>
+<cell multicolumn="1" alignment="center" valignment="top" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+SiLabs C8051F120 example
+\end_layout
+
+\end_inset
+</cell>
+<cell multicolumn="2" alignment="center" valignment="top" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+<cell multicolumn="2" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+<cell multicolumn="2" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\newline
+Usually the hardware uses some sfr (an output port or an internal sfr) to
+ select a bank and put it in the banked area of the memory map.
+ Because the selected bank usually becomes active immediately you cannot
+ jump call directly from one bank to another and need to use a so-called
+ trampoline in the common area.
+ For SDCC an example trampoline is in crtbank.asm and you may need to change
+ it to your 8051 derivative or schematic.
+ The presented code is written for the C8051F120.
+\newline
+
+\newline
+When calling a banked function
+ SDCC will put the LSB of the functions address in register R0, the MSB
+ in R1 and the bank in R2 and then call this trampoline __sdcc_banked_call.
+ The current selected bank is saved on the stack, the new bank is selected
+ and an indirect jump is made.
+ When the banked function returns it jumps to __sdcc_banked_ret which restores
+ the previous bank and returns to the caller.
+\end_layout
+
+\begin_layout Subsubsection
+Software
+\end_layout
+
+\begin_layout Standard
+When writing banked software using SDCC you need to use some special keywords
+ and options.
+ You also need to take over a bit of work from the linker.
+\newline
+
+\newline
+To create a function
+ that can be called from another bank it requires the keyword banked.
+ The caller must see this in the prototype of the callee and the callee
+ needs it for a proper return.
+ Called functions within the same bank as the caller do not need the banked
+ keyword nor do functions in the common area.
+ Beware: SDCC does not know or check if functions are in the same bank.
+ This is your responsibility!
+\newline
+
+\newline
+Normally all functions you write end up in
+ the segment CSEG.
+ If you want a function explicitly to reside in the common area put it in
+ segment HOME.
+ This applies for instance to interrupt service routines as they should
+ not be banked.
+\end_layout
+
+\begin_layout Standard
+Functions that need to be in a switched bank must be put in a named segment.
+ The name can be mostly anything upto eight characters (e.g.
+ BANK1).
+ To do this you either use --codeseg BANK1 on the command line when compiling
+ or #pragma codeseg BANK1 at the top of the C source file.
+ The segment name always applies to the whole source file and generated
+ object so functions for different banks need to be defined in different
+ source files.
+\newline
+
+\newline
+When linking your objects you need to tell the linker where
+ to put your segments.
+ To do this you use the following command line option to SDCC: -Wl-b BANK1=0x180
+00.
+ This sets the virtual start address of this segment.
+ It sets the banknumber to 0x01 and maps the bank to 0x8000 and up.
+ The linker will not check for overflows, again this is your responsibility.
+\end_layout
+
+\begin_layout Standard
\begin_inset VSpace bigskip
\end_inset
\begin_layout Enumerate
Add DEVICE to
\family typewriter
-/path/to/sdcc/device/lib/pics.all
+/path/to/sdcc/device/lib/pic16/pics.all
\family default
(and
\family typewriter
\end_inset
- or -
+
+\series default
+or
+\series bold
+ -
\begin_inset ERT
status collapsed
'__data' instead of 'data'.
\end_layout
+\begin_layout Itemize
+Integer promotion of variable arguments is not performed if the argument
+ is explicitly taypecasted unless the
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
+
+\end_inset
+
+
+\series default
+or
+\series bold
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+
+\end_inset
+
+
+\series default
+ command line options are used.
+\end_layout
+
+\begin_deeper
+\begin_layout Verse
+
+\family typewriter
+void vararg_func (char *str, ...) { str; }
+\newline
+
+\newline
+void main (void)
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+char c = 10;
+\newline
+
+\newline
+\InsetSpace ~
+\InsetSpace ~
+/* argument
+ u is promoted to int before
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+* passing to function */
+\newline
+\InsetSpace ~
+\InsetSpace ~
+vararg_func ("%c", c);
+\newline
+
+\newline
+\InsetSpace ~
+\InsetSpace ~
+/*
+ argument u is not promoted to int,
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+* it is passed as char to function
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+* if
+ --std-cXX is not defined;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+* is promoted to int before passing
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+* to function
+ if --std-cXX is defined */
+\newline
+\InsetSpace ~
+\InsetSpace ~
+vararg_func ("%bc", (char)u);
+\newline
+}
+\end_layout
+
+\end_deeper
\begin_layout Section
Cyclomatic Complexity
\begin_inset LatexCommand \index{Cyclomatic complexity}
\end_layout
\begin_layout Standard
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net#Who}
+\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/#Who}
\end_inset
projects / fw / sdcc / blobdiff