[fpc-devel] Code generated for the embedded arm port for lpc1768 (armv7m)

[Jeppe Græsdal Johansen]

Are you sure those are the precise steps you took? Because that should 
work as you expected it unless you have a broken binutils version. It's 
normally very quick to complain about incompatible ARM versions

Try to disassemble the objects in the source directory at 
rtl/units/arm-embedded
Those should largely contain variable length thumb2 code.

Den 23-10-2014 20:15, Sietse Achterop skrev:
>   Hello,
> I am trying to get the embedded version of fpc for arm to work.
> Currently i try it for the lpc1768 from NXP using the lpcxpresso board.
> The example compiles, but doesn't run on the target...
>
> I created a simple example and it seems that the code it generates is 
> NOT thumb2 code.
> I disassembled the elf-file generated by fpc using 
> "arm-none-eabi-objdump -S"
> I also disassembled it using the debugger "arm-none-eabi-gdb"
> Here is a fragment of the code from both:
>
> From objdump:
> 000001c4 <FPC_INITIALIZEUNITS>:
>  1c4:    e92d4070     push    {r4, r5, r6, lr}
>  1c8:    ebfffff5     bl    1a4 <SYSTEM_$$_FPC_CPUINIT>
>  1cc:    e59f006c     ldr    r0, [pc, #108]    ; 240 
> <FPC_INITIALIZEUNITS+0x7c>
>  1d0:    e5904000     ldr    r4, [r0]
>  1d4:    e3a05001     mov    r5, #1
>  1d8:    e1540005     cmp    r4, r5
>  1dc:    ba00000f     blt    220 <FPC_INITIALIZEUNITS+0x5c>
>
> From gdb
>    0x000001c4 <fpc_initializeunits+0>:        70 40 eors             
> r0, r6
>    0x000001c6 <fpc_initializeunits+2>:        2d e9 f5 ff             
> stmdb    sp!, {r0, r2, r4, r5, r6, r7, r8, r9, r10, r11, r12, sp, lr, pc}
> => 0x000001ca <fpc_initializeunits+6>:        ff eb 6c 
> 00                          ; <UNDEFINED> instruction: 0xebff006c
>    0x000001ce <fpc_initializeunits+10>:        9f e5 
> b.n                     0xfffffd10
>    0x000001d0 <fpc_initializeunits+12>:        00 40 
> ands                     r0, r0
>    0x000001d2 <fpc_initializeunits+14>:        90 e5 
> b.n                     0xfffffcf6
>    0x000001d4 <fpc_initializeunits+16>:        01 50 
> str                     r1, [r0, r0]
>    0x000001d6 <fpc_initializeunits+18>:        a0 e3 
> b.n                     0x91a
>    0x000001d8 <fpc_initializeunits+20>:        05 00 
> movs                     r5, r0
>    0x000001da <fpc_initializeunits+22>:        54 e1 
> b.n                     0x486
>    0x000001dc <fpc_initializeunits+24>:        0f 00 
> movs                     r7, r1
>
> Note how the interpretation of the code is different, as is the length 
> of most instructions.
> It looks to me as if the code in the elf-file are (mostly) 32-bit 
> values, while the debugger does interpret thee code as thumb2 (i think).
>
> In the Makefile in rtl/embedded I find:
>
>     ifeq ($(SUBARCH),armv7m)
>     CPU_UNITS=lm3fury lm3tempest stm32f10x_ld stm32f10x_md 
> stm32f10x_hd stm32f10x_xl stm32f10x_conn stm32f10x_cl lpc13xx lpc1768 
> lm4f120  xmc4500 cortexm3 cortexm4 # thumb2_bare
>     endif
>
> So that suggest (via the comment) that fpc can do thumb2 code, which 
> it should for cortexm3.
>
> My PC is debian/jessie/64bit:  Free Pascal Compiler version 
> 2.6.4+dfsg-3 [2014/07/12] for x86_64
> I got the sourcecode for the port from svn as described on the website.
> To create the port I do:
>
>     make clean buildbase installbase CROSSINSTALL=1 OS_TARGET=embedded 
> CPU_TARGET=arm SUBARCH=armv7m BINUTILSPREFIX=arm-none-eabi-
>
> For the binutils I use the (current) stuff for the lpc1768 from NXP: 
> lpcxpresso_7.4.0_229
>
> To create a program I do:
>
>     ppcrossarm -Ch1024 -Cs1024 -Tembedded -Parm -Cparmv7m 
> -XParm-none-eabi- -Wplpc1768 -vu prog.p
>
> Is there anybody that did get this port to work?
>
>   Thanks in advance,
>        Sietse
>
>
>
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