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   对嵌入式target（目标操作系统，目标架构）的支持正在开发中，只支持少数控制器。尽管如此，为嵌入式arm设备做程序还是可行的。嵌入式target没有操作系统，只有几kB的RAM和几十kB的flash。一个典型的target就是NXP公司的LPC家族的流行的设备诸如LPC2124，它拥有16kB的RAM和256kB的flash，使用ARM7的指令集。

嵌入式移植

状态

• 仅仅在svn上的2.3.1版本才能得到可用的支持
• 当前仅有arm嵌入式设备得到支持
• 当前支持的控制器仅限于NXP LPC和ATMEL AT91控制器。如果你有兴趣对其他控制器提供支持，请在这儿捐献你的代码fpc-devel mailing list然后写封信使得我们可以讨论是否加入这个支持。

ARM嵌入式

构建

从svn上获取最新的FPC源码：

 svn co http://svn.freepascal.org/svn/fpc/trunk fpc

获取ARM嵌入式binutils。

对于windows,他们可以在 http://svn.freepascal.org/svn/fpcbuild/binaries/i386-win32 得到。你可以checkout所有的目录或者仅仅手工下载arm-embedded-ar.exe，arm-embedded-as.exe，arm-embedded-ld.exe，arm-embedded-strip.exe，arm-embedded-objdump.exe和arm-embedded-objcopy.exe。把这些utils放到被PATH变量包含的目录。

编译FPC对arm-embedded的支持：

 cd fpc
 make clean buildbase installbase CROSSINSTALL=1 OS_TARGET=embedded CPU_TARGET=arm

以上的命令仅仅编译编译器和rtl，因为受限于嵌入式系统的性能编译所有的包是无意义的。不管怎样，要小心不要覆盖了已经存在于系统上的arm编译器。如果这可能发生，INSTALL_PREFIX必须被指定，以使得安装程序被放入另一个文件夹。

Testing

Below you find a simple example program, save it as tled1.pp to follow the description. The program is made for development boards like the LPC-WEB from OLIMEX (http://www.olimex.com/dev/lpc-e2124.html). When you press button 1, led 1 lights for a certain time, same for button 2 and led 2.

<delphi> procedure Wait(d : dword); begin

 while d<>0 do
   dec(d);

end;

begin

 { initialize PLL }
 InitPLL(2,1);

 { initialize LEDs }
 { port 0.8: output }
 TBitvector32(GPIO0_IODIR)[8]:=1;
 { port 0.10: output }
 TBitvector32(GPIO0_IODIR)[10]:=1;

 { turn off both LEDs }
 TBitvector32(GPIO0_IOSET)[8]:=1;
 TBitvector32(GPIO0_IOSET)[10]:=1;

 { initialize button inputs }
 { port 0.9: input }
 TBitvector32(GPIO0_IODIR)[9]:=0;
 { port 0.15: input }
 TBitvector32(GPIO0_IODIR)[15]:=0;

 { endless loop}
 while true do
   begin

     { button 1 pressed }
     if TBitvector32(GPIO0_IOPIN)[15]=0 then
       begin
         { turn on LED, inverse logic }
         TBitvector32(GPIO0_IOCLR)[8]:=1;
         { wait }
         Wait(500000);
         {  turn off LED, inverse logic }
         TBitvector32(GPIO0_IOSET)[8]:=1;
     end;

     { button 2 pressed }
     if TBitvector32(GPIO0_IOPIN)[9]=0 then
       begin
         { turn on LED, inverse logic }
         TBitvector32(GPIO0_IOCLR)[10]:=1;
         { wait }
         Wait(500000);
         { turn off LED, inverse logic }
         TBitvector32(GPIO0_IOSET)[10]:=1;
     end;
   end;

end. </delphi>

If FPC for arm-embedded is installed as described above, the program can be compiled by

 fpc -Parm -Tembedded -Wplpc2124 tled1.pp

 -Parm

tells the compiler to compile for arm.

 -Tembedded

tells the compiler to compile for the embedded target.

 -Wplpc2124

tells the compiler to compile for the NXP LPC 2124. This has two effects: first, a unit (lpc21x4 in this case) containing the startup code and the port etc. definitions for this controller is loaded. Further, the compiler uses a linker script which fits the needs of this controller.

The result of the compiler is a .hex file which can be programmed by the NXP flash programming utility.

Adding new controllers

Adding a new controller type requires basically three steps: first, extend the compiler so it knows about the name of the controller then add a linker script and finally create an rtl unit with the register definitions and the startup code.

Useful links

• http://de.wikipedia.org/wiki/Intel_HEX
• http://www.nxp.com/products/microcontrollers/support/software_download/lpc2000/
• http://www.nxp.com/acrobat_download/usermanuals/UM10114_3.pdf
• Jim Lynch: Using Open Source Tools for AT91SAM7 Cross Development - Revision B http://www.atmel.com/dyn/resources/prod_documents/atmel_tutorial_source.zip