[U-Boot-Users] Optimized U-boot : Optimization of UCC and TFTP codes of UBOOT

[Wolfgang Denk]

In message <1034141BCEB1424784F14A38BD006D82165BB5 at zin33exm22.fsl.freescale.net> you wrote:
> 
>                 I am currently trying to optimize the Ethernet driver
> initialization code and the Tftp code of the U-boot so that it can fit
> into the I2CPROM of the 8321 LCDB board whose PROM size is 32 KB, but
> out of which only 18 KB is available for the code. 

I recommend to check code and data sizes of  a  few  objects  in  the
U-Boot  tree,  and  to  re-consiser if it is worth to spent effort on
this.

...
> do bare initialization of the Ethernet and does not implement any
> complex functionalities. The only functions that are required are the
> (1) TX event (2) RX event (3) Error Control and (4)CRC.

Yes, and you will need initialization of the CPU, the RAM (for stack
and I/O buffers, and you will need support for the environment and
code to read it (for things like MAC address), and you may want to be
able to see what's happening, so a minimal serial driver is needed,
which in turn asks for things like printf, and... and...

> The Tftp code (present in the net directory of the U-Boot) then should
> support a simple file transfer protocol implemented in a minimal
> fashion.

Right. That's what the initiual 'T' stands for. I don;t think that the
current code is overly bloated.

> The Ethernet initialization code and the Tftp code size should not be
> more than 18 KB. 

Let's give it a quick check on a TQM834x system:

-> size cpu/mpc83xx/*.o net/*.o lib_generic/string.o lib_generic/vsprintf.o
   text    data     bss     dec     hex filename
    468      24       0     492     1ec cpu/mpc83xx/cpu.o
    304       0       0     304     130 cpu/mpc83xx/cpu_init.o
   1868       8       0    1876     754 cpu/mpc83xx/i2c.o
    104       0       0     104      68 cpu/mpc83xx/interrupts.o
      0       0       0       0       0 cpu/mpc83xx/resetvec.o
      0       0       0       0       0 cpu/mpc83xx/spd_sdram.o
   1260     248       0    1508     5e4 cpu/mpc83xx/speed.o
  14584      92       0   14676    3954 cpu/mpc83xx/start.o
   1804      76       0    1880     758 cpu/mpc83xx/traps.o
   2296     120       0    2416     970 net/bootp.o
   2588      76      12    2676     a74 net/eth.o
   6528     324     204    7056    1b90 net/net.o
   4784     208    2224    7216    1c30 net/nfs.o
    576      48       0     624     270 net/rarp.o
      0       0       0       0       0 net/sntp.o
   2220     196      52    2468     9a4 net/tftp.o
   1256       4       0    1260     4ec lib_generic/string.o
   3032      24       0    3056     bf0 lib_generic/vsprintf.o
==============================================================
  43467    1448

Just this fraction of the U-Boot code gives a total of more than 44 kB.
I doubt that you can optimize away 60% of this...

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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