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[U-Boot-Users] [Fwd: Re: reducing size of u-boot binary]

U-Boot-Users vibi 2 participants 2 messages Dec 15, 2007 – Dec 17, 2007

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#0 lore raw

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

Quoted 22 lines · Jerry Van Baren
Quoted 11 lines · vibi

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

#1 lore raw
Quoted 31 lines · vibi
Quoted 12 lines · Jerry Van Baren
Quoted 11 lines · vibi

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

Quoted 8 lines

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.

Quoted 7 lines

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