[U-Boot] common/xyzmodem.c, ymodem, slow behavior receiving bytes

[Wolfgang Denk]

Dear Angelo,

In message <20121114094706.GA5697 at angel3> you wrote:
> 
> > Which exact tool chain are you using to build the code?
> 
> I tested 2 different toolchains, 
> 
> m68k-elf-gcc (Sourcery CodeBench Lite 2011.09-21) 4.6.1

OK, this should be recent enough...

> > It is set because it is useful to some (those in the need of debugging
> > their code) and does not hurt others.
> 
> My question becouse sometime embedded programmers fight for a bite free 
> in the flash. On limited boards like mine (4M Flash) once kernel and 
> some apps are stored, very small size remain for u-boot and some n.v. data 
> storage. But no problem for me, i change flags as needed eventually.

-g has zero impact on the image size!!  The debug symbol tables are
only present in the ELFK file, but they are not included in the
binary image you install on your flash.  This is what I mean by "it
does not hurt others" - the U-Boot image size with or without -g is
exactly the same.

> Sure, 20 Mhz boards are able to handle 115200 as well. So there is clearly
> something non working properly in my custom board. First thought is the 
> sdram not well initialized, resulting in very slow execution of the u-boot 
> code. Is there a way in u-boot to test code execution speed ?

Not directly.  If you just want to compare boards it is often
sufficient to do this with some shell loops, say:

	date ; for i in 1 2 3 4 5 6 7 8 9 0 ; do
	for j in 1 2 3 4 5 6 7 8 9 0 ; do
	for k in 1 2 3 4 5 6 7 8 9 0 ; do
	setenv foo 1 ; setenv foo
	done ; done ; done ; date

Best regards,

Wolfgang Denk

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