* [U-Boot-Users] [Fwd: Re: reducing size of u-boot binary]
@ 2007-12-15 6:27 vibi
2007-12-17 13:38 ` Jerry Van Baren
0 siblings, 1 reply; 2+ messages in thread
From: vibi @ 2007-12-15 6:27 UTC (permalink / raw)
To: u-boot
dear jerry,
thanks for your reply.i am using u-boot 1.1.5 .my binary is only 90kb &
i still wanted to reduce the size.i thought compiling u-boot is like
compiling linux kernel,ie source file for the disabled commands wont get
compiled,now i understood that i was wrong.
i wanted to reduce size to less than 90kb because of constraints in
available flash memory space.
i have done it by disabling bootp & rarp by using #define macros
i didnt find option for that in /include/cmd_confdefs.h .
once again i thank you for your response
thanks & regards
vibi sreenivasan
On Fri, 2007-12-14 at 07:20 -0500, Jerry Van Baren wrote:
> vibi wrote:
> > hello,
> > can any one please tell me how to reduce the size of u-boot.bin.
> > i tried by disabling commands in the
> > include/config/at91rm9200dk.h,as per the read me document
> > even after this when i compile,i was unable to decrease the
> > size.
> >
> > thanks in advance.
> >
> > regards
> > vibi sreenivasan
>
> How big is your binary, why do you need to reduce its size? I ask
> because most of the time this question is the result of a link gone bad
> where part of the linked binary lives in low memory space and part lives
> in high memory space. As a result, the .bin has a huge amount of filled
> (unused) data between the two.
>
> Best regards,
> gvb
>
^ permalink raw reply [flat|nested] 2+ messages in thread
* [U-Boot-Users] [Fwd: Re: reducing size of u-boot binary]
2007-12-15 6:27 [U-Boot-Users] [Fwd: Re: reducing size of u-boot binary] vibi
@ 2007-12-17 13:38 ` Jerry Van Baren
0 siblings, 0 replies; 2+ messages in thread
From: Jerry Van Baren @ 2007-12-17 13:38 UTC (permalink / raw)
To: u-boot
vibi wrote:
> On Fri, 2007-12-14 at 07:20 -0500, Jerry Van Baren wrote:
>> vibi wrote:
>>> hello,
>>> can any one please tell me how to reduce the size of u-boot.bin.
>>> i tried by disabling commands in the
>>> include/config/at91rm9200dk.h,as per the read me document
>>> even after this when i compile,i was unable to decrease the
>>> size.
>>>
>>> thanks in advance.
>>>
>>> regards
>>> vibi sreenivasan
>> How big is your binary, why do you need to reduce its size? I ask
>> because most of the time this question is the result of a link gone bad
>> where part of the linked binary lives in low memory space and part lives
>> in high memory space. As a result, the .bin has a huge amount of filled
>> (unused) data between the two.
>>
>> Best regards,
>> gvb
>
> dear jerry,
> thanks for your reply.i am using u-boot 1.1.5 .my binary is only 90kb &
> i still wanted to reduce the size.i thought compiling u-boot is like
> compiling linux kernel,ie source file for the disabled commands wont get
> compiled,now i understood that i was wrong.
>
> i wanted to reduce size to less than 90kb because of constraints in
> available flash memory space.
>
> i have done it by disabling bootp & rarp by using #define macros
> i didnt find option for that in /include/cmd_confdefs.h .
>
> once again i thank you for your response
>
> thanks & regards
> vibi sreenivasan
Hi Vibi,
90K is already pretty small for a u-boot image. I don't know how small
u-boot can get, but rule of thumb is 128K is a reasonable size for good
functionality.
<http://www.denx.de/wiki/view/UBoot/DesignPrinciples>
With respect to the commands, disabling commands should cut the actual
command code out via #ifdefs, so disabling commands should result in a
smaller image, even though all the files are still compiled.
a) There is a limit to how much can be cut out by removing commands.
There still is a lot of support code necessary.
b) It is possible that a command that is disabled needs a support
function, but the support function isn't disabled so not all the
potential savings are realized.
Note that u-boot is going to a better configuration and linking
methodology that doesn't compile unused pieces (as opposed to compiling
code that is #ifdefed out). I don't expect this to save any significant
amount of memory, but it is possible that it will turn up and fix errors
or inefficiencies with the current method.
Best regards,
gvb
^ permalink raw reply [flat|nested] 2+ messages in thread
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2007-12-15 6:27 [U-Boot-Users] [Fwd: Re: reducing size of u-boot binary] vibi
2007-12-17 13:38 ` Jerry Van Baren
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