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3GB kernel binary!
Posted: Sat Oct 08, 2005 6:25 pm
by Colonel Kernel
Wow, something went really wrong here. For a long time I've been running two parallel builds of my kernel -- one that passes -D NDEBUG to gcc (my "free" build) and one without (my "checked" build). I added -O3 to the compiler settings for my free build, and suddenly my kernel binary grows from 23KB to 3GB!
I'm guessing there is something subtle that I don't understand about my linker script, since my kernel is linked to run in the higher half. Here it is:
Code: Select all
ENTRY (StartPrecursor)
OUTPUT_FORMAT(binary)
SECTIONS
{
. = 0xC0100000;
.text :
{
*(.text)
*(.rodata)
}
.data ALIGN (0x1000) :
{
*(.data)
}
.bss :
{
_sbss = .;
*(COMMON)
*(.bss)
_ebss = .;
}
}
Are there any magical sections I'm not aware of that would only show up when compiling with -O3 (or any of the -O's, they all do the same thing)? BTW, I'm using a gcc cross-compiler (built from gcc 3.4.1 sources according to the instructions on the OS FAQ).
Re:3GB kernel binary!
Posted: Sat Oct 08, 2005 9:07 pm
by pradeep
Well i really don't know the answer but the same question was posted long back and i think it was answered by Pype.Clicker better he could give you the answer
Re:3GB kernel binary!
Posted: Sat Oct 08, 2005 11:34 pm
by Colonel Kernel
Thanks for mentioning Pype's name -- that finally got me some results in the forum's search function.
Apparently, using -O3 was causing some of the string constants to go in sections named .rodata.str
x.
y. This fixed it:
Code: Select all
ENTRY (StartPrecursor)
OUTPUT_FORMAT(binary)
SECTIONS
{
. = 0xC0100000;
.text :
{
*(.text)
*(.rodata*) /* <--- aha! */
}
.data ALIGN (0x1000) :
{
*(.data)
}
.bss :
{
_sbss = .;
*(COMMON)
*(.bss)
_ebss = .;
}
}
Re:3GB kernel binary!
Posted: Sun Oct 09, 2005 4:15 am
by Pype.Clicker
;D ROFL. Just invoke my name and your kernel will automagically debug
For I am the mighty wizard of OS. How wizzy your OS is, the wizard has a wizzer for your for nothing is too wizzy for the wize wizard of OS. ;D
(seems i'm in a hilarous-like-BI day
)
Re:3GB kernel binary!
Posted: Sun Oct 09, 2005 1:13 pm
by DruG5t0r3
Follow the binary brick wall ;D
Re:3GB kernel binary!
Posted: Sun Oct 09, 2005 3:11 pm
by 0Scoder
lol, could be an advert for broadband: Follow the megabit road could be a nice slogan
Re:3GB kernel binary!
Posted: Sun Oct 09, 2005 3:26 pm
by Pype.Clicker
@oscoder: i suppose "follow the white megrabit" will hit broader audience
@drugstore: actually, it's "The Road of Yellow Bits".