Compiling an optimized Samdroid Kernel

[antibyte]

Here is how to compile LeshaKs Samdroid Kernel with an optimized
Toolchain and Kernel config.
Using his pre-setup development enviroment here:
[Dev] VMWare image for build i5700 kernel (2.6.29 for Android 2.1)

I hope i did not forget something.

Toolchain
-----------
ct-ng menuconfig :

Target options --->
"Architecture level" -> "armv6k" // enable arm v6k extensions
"Target CFLAGS"-> "-O3" // enable level 3 optimizations

Rebuild Toolchain.

Kernel
--------

make menuconfig :

System Type --->
*** Processor Type ***[*] Support ARM V6K processor extensions // was disabled

*** Processor Features ***

[ ] Disable branch predicition // was enabled

Modules Folder
-----------------
_mm1 script:

add "CFLAGS=-O3" to the "make ..." line

_kmake and _kmake_s ( LeshaKs Scripts in ~/bin)
----------------------------------------------------------

"make -j2" ---> "make -j2 CFLAGS=-O3"
"make" ---> "make CFLAGS="-O3"


Resulting Kernel can be found here :

Wohoo ! more speed for your Spica !

[antibyte]

Did lots of tests and came up with a very fast second version :

Wohoo ! more speed for your Spica !

Instructions for building will be updated this evening.

[LeshaK]

Did lots of tests and came up with a very fast second version

Could you get new su2 from sbin at master from leshak's i5700-leshak-initramfs2 - GitHub
for your next build

[pixiejoe]

quite same results as v1

[antibyte]

quite same results as v1

You mean from Linpack ?
Linpack only gets faster as it gets more CPU time in this case i think.
But the overall performance and graphics performance is better.
I found out that i had some settings wrong and doing a recompile
at the moment. Maybe it gets a little bit better

[sotipay]

can't wait for your next kernel antibyte, keep up the good work!

[bharaniviswan]

nice work @antibyte

[equk]

Did lots of tests and came up with a very fast second version :

Wohoo ! more speed for your Spica !

Instructions for building will be updated this evening.

I had 2 crashes last night causing the phone to reboot & the only thing I changed was the kernel

not really sure why it's causing reboots

[antibyte]

Just dont use JIT, there is no kernel that can fix the bugs in JIT

---------- Post added at 01:22 AM ---------- Previous post was at 12:30 AM ----------

One word of warning if someone is going to build his own Spica-kernel :

Do never ever try to build the "cmm" memory management kernel module (s3c-cmm.so) with optimizations enabled (-O)
I had a opengl benchmarking app hanging every time when i did this, and so i did
disable optimizations for this module until today.
But the Spica is really faster if this one is optimized too, so i thought i enable the optimizations
again. This worked for a while, but then the phone totaly crashed and graphics controller
got crazy. Even after pulling the battery and restarting i had stripes and flickering on the display for a while.
It seems the optimized module badly corrupted the memory. As this could lead to all sorts of serious
problems, dont use compiler optimizations on this module ! Make sure that CFLAGS=-O0 for cmm

[Second_Fry]

Компиляция linux-утилит под Android - Hack wiki

-march=armv6kz -mtune=arm1176zjf-s -mfpu=vfp -Os

March отличается + можно задать mtune и mfpu.

[UPD:] CFLAGS="-O3 -fomit-frame-pointer" (omit-frame-pointer is stable and fast on my gentoo)