[Sony Xperia P, U, Sola, Go] munjeni:
Ok, but I tried two versions but all had that battery drain so I analysed stock kernel by disasembling him and found these things was wrong in custom boot images... So right command for generating boot image is:

python mkelf.py -o kernel.elf zImage@0x00008000 initrd.gz@0x01000000,ramdisk

than you need to hex edit generated boot image:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000 7F 45 4C 46 01 01 01 61 00 00 00 00 00 00 00 00 .ELF...a........
00000010 02 00 28 00 01 00 00 00 00 80 00 00 34 00 00 00 ..(......€..4...
00000020 00 00 00 00 00 00 00 00 34 00 20 00 [COLOR="Red"]02[/COLOR] 00 00 00 ........4. .....

0x02 mean 2 parts so to include third part (elf.3) you need to change 0x02 to 0x03

than you need to inject elf.3 by hex editing and implementing these elf.3 between 0x70 and 0x4d0 offset, final kernel.elf looks like:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000 7F 45 4C 46 01 01 01 61 00 00 00 00 00 00 00 00 .ELF...a........
00000010 02 00 28 00 01 00 00 00 00 80 00 00 34 00 00 00 ..(......€..4...
00000020 00 00 00 00 00 00 00 00 34 00 20 00 [COLOR="Red"]03[/COLOR] 00 00 00 ........4. .....
00000030 00 00 00 00 01 00 00 00 00 10 00 00 00 80 00 00 .............€..
00000040 00 80 00 00 D4 D8 3A 00 D4 D8 3A 00 00 00 00 00 .€..ÔŘ:.ÔŘ:.....
00000050 00 00 00 00 01 00 00 00 D4 E8 3A 00 00 00 00 01 ........Ôč:.....
00000060 00 00 00 01 CB 58 23 00 CB 58 23 00 00 00 00 80 ....ËX#.ËX#....€
00000070 [COLOR="Red"]00 00 00 00 53 49 4E 21 94 00 00 00 00 00 00 00 ....SIN!”.......
00000080 00 00 00 00 30 04 00 00 30 04 00 00 04 00 00 00 ....0...0.......
00000090 04 00 00 00 02 00 00 00 04 2D 01 00 00 00 00 00 .........-......
000000A0 00 00 52 00 00 00 00 00 00 00 94 20 F1 77 14 10 ..R.......” ńw..
000000B0 CF 4B CB EE F8 6C 64 9C F3 CC B3 8D 6C 24 C1 D6 ĎKËîřldśóĚłŤl$ÁÖ
000000C0 6B 6F 68 B2 9B 23 A4 3B CF C1 52 39 00 00 04 C4 koh˛›#¤;ĎÁR9...Ä
000000D0 00 49 84 EC 20 D9 C4 BB 73 4F EF C1 32 58 AF 09 .I„ě ŮÄ»sOďÁ2XŻ.
000000E0 7F 35 E4 A1 3B 5A 24 AA ED 25 0E AD 1C 00 FA D9 .5äˇ;Z$Şí%.*..úŮ
000000F0 63 CB 77 9F 09 00 00 03 C8 00 01 02 C1 02 BF 30 cËwź....Č...Á.ż0
00000100 82 02 BB 30 82 01 A3 A0 03 02 01 02 02 01 02 30 ‚.»0‚.Ł .......0
00000110 0D 06 09 2A 86 48 86 F7 0D 01 01 0B 05 00 30 17 ...*†H†÷......0.
00000120 31 15 30 13 06 03 55 04 03 14 0C 53 31 5F 52 6F 1.0...U....S1_Ro
00000130 6F 74 5F 33 30 36 35 30 1E 17 0D 31 31 31 31 31 ot_30650...11111
00000140 38 31 33 33 39 33 33 5A 17 0D 33 31 31 31 32 30 8133933Z..311120
00000150 31 33 33 39 33 33 5A 30 10 31 0E 30 0C 06 03 55 133933Z0.1.0...U
00000160 04 03 14 05 53 31 5F 53 57 30 82 01 22 30 0D 06 ....S1_SW0‚."0..
00000170 09 2A 86 48 86 F7 0D 01 01 01 05 00 03 82 01 0F .*†H†÷.......‚..
00000180 00 30 82 01 0A 02 82 01 01 00 B4 2A 22 EE 88 E3 .0‚...‚...´*"î.ă
00000190 29 19 99 6E B8 2E 7D F5 5D 79 70 1C 80 1C 0E B7 ).™n¸.}ő]yp.€..·
000001A0 42 45 E8 23 45 9D 66 45 6E 88 50 B6 11 DF 6C 55 BEč#EťfEn.P¶.ßlU
000001B0 73 29 F3 E1 32 03 0F F0 92 EE F3 3D 0B 82 5D 51 s)óá2..đ’îó=.‚]Q
000001C0 5C 9D 8E 61 35 42 B7 EE FF 5B AB 70 B8 36 1A A9 \ťŽa5B·î˙[«p¸6.©
000001D0 55 42 B8 9C 9B EE CB 33 5D 7F FC BA 3E CA 8D 0B UB¸ś›îË3].üş>ĘŤ.
000001E0 A6 60 8D 81 82 B7 53 AD 91 66 5B 70 B7 B0 AE 12 ¦`Ť.‚·S*‘f[p·°®.
000001F0 FC A8 EC C1 34 58 7F 23 22 50 57 84 E4 81 C9 A0 ü¨ěÁ4X.#"PW„ä.É
00000200 0B 30 D9 F0 18 73 57 6B AC 64 51 61 DA 2E 55 48 .0Ůđ.sWk¬dQaÚ.UH
00000210 2C 0F A3 85 28 B1 01 D3 0E 1B DA C6 29 40 77 8A ,.Ł…(±.Ó..ÚĆ)@wŠ
00000220 36 0E 50 8F 48 1E F4 3D 73 60 14 52 C7 A6 73 56 6.PŹH.ô=s`.RÇ¦sV
00000230 78 56 58 E8 2F B0 12 76 20 FD C3 E7 D3 A6 E5 5B xVXč/°.v ýĂçÓ¦ĺ[
00000240 2B 84 1F 9C 9C E1 1D 9F 3A 58 07 BA C2 96 08 97 +„.śśá.ź:X.şÂ–.—
00000250 00 54 76 7F A3 1B AE 33 6A FE BF 58 CC 3A E0 23 .Tv.Ł.®3jţżXĚ:ŕ#
00000260 B0 C2 C0 8E 42 D7 AF A5 56 D9 66 23 A4 B1 2B C7 °ÂŔŽB×ŻĄVŮf#¤±+Ç
00000270 BF 44 FA 91 37 A8 24 09 E8 0F 65 6B 8C 50 DB CC żDú‘7¨$.č.ekŚPŰĚ
00000280 0F B4 A5 F6 83 DB 5A 26 FF 6F 02 03 01 00 01 A3 .´Ąö.ŰZ&˙o.....Ł
00000290 19 30 17 30 0A 06 03 55 04 05 04 03 02 01 01 30 .0.0...U.......0
000002A0 09 06 03 55 1D 13 04 02 30 00 30 0D 06 09 2A 86 ...U....0.0...*†
000002B0 48 86 F7 0D 01 01 0B 05 00 03 82 01 01 00 A5 C7 H†÷.......‚...ĄÇ
000002C0 B1 A5 30 75 EA 27 57 DB 23 55 34 1C E9 1A 50 BD ±Ą0uę'WŰ#U4.é.P˝
000002D0 64 B0 53 9F 86 BC 72 C5 89 9F 5F DD 1A C0 4C ED d°Sź†ĽrĹ‰ź_Ý.ŔLí
000002E0 81 A7 B3 9C D8 89 F7 0A 7C 26 7E F6 67 8E F1 C0 .§łśŘ‰÷.|&~ögŽńŔ
000002F0 E9 A0 63 0E 42 32 F9 C6 FF C2 4B 4C 93 7E 4A 27 é c.B2ůĆ˙ÂKL“~J'
00000300 EF 5B CF 22 04 B8 31 28 C5 B7 73 5E 36 BC D0 A3 ď[Ď".¸1(Ĺ·s^6ĽĐŁ
00000310 CB 53 C2 D8 88 5B 7F 78 1B E6 B2 F5 9B 9B 25 9E ËSÂŘ.[.x.ć˛ő››%ž
00000320 F5 93 B5 92 13 44 D5 C0 30 7D B7 4B 4A 00 4E CB ő“µ’.DŐŔ0}·KJ.NË
00000330 12 4A 91 AE 79 F1 64 64 51 8A D7 A3 89 5A AC AC .J‘®yńddQŠ×Ł‰Z¬¬
00000340 BD EC 82 62 7B 26 48 AB FC 54 CB EC D0 8D C9 E2 ˝ě‚b{&H«üTËěĐŤÉâ
00000350 A5 D0 FF 9A ED E0 36 5F 71 25 E5 6D 3B 65 ED D9 ĄĐ˙šíŕ6_q%ĺm;eíŮ
00000360 35 FB D8 94 E6 DD 14 C8 DA 97 08 C7 B7 93 2F EC 5űŘ”ćÝ.ČÚ—.Ç·“/ě
00000370 C4 8C DA 30 59 68 14 8B EF DA E0 34 5C E1 24 41 ÄŚÚ0Yh.‹ďÚŕ4\á$A
00000380 3A 40 7C 51 60 C3 6B B6 A3 F4 DE 39 D3 D4 F5 60 :@|Q`Ăk¶ŁôŢ9ÓÔő`
00000390 C9 EB 09 64 36 5E 12 71 ED 6C C0 53 BF 58 28 8E Éë.d6^.qílŔSżX(Ž
000003A0 16 D5 68 24 1C 48 F8 A9 11 FF C6 0A 41 3A 02 23 .Őh$.Hř©.˙Ć.A:.#
000003B0 37 A9 E7 9F C5 61 2E B5 49 D3 B4 B5 73 A9 02 01 7©çźĹa.µIÓ´µs©..
000003C0 00 51 0B DB 77 B1 72 81 F9 B4 04 74 EE DE 1C 32 .Q.Űw±r.ů´.tîŢ.2
000003D0 CD 98 22 05 27 35 83 0D 50 61 B3 34 3A 04 AB CF Í.".'5..Pał4:.«Ď
000003E0 25 CD 25 76 86 A9 4F EA AA D6 5A 83 3A 77 09 9B %Í%v†©OęŞÖZ.:w.›
000003F0 F7 D0 E5 27 28 83 20 4A A1 DD 88 E4 3C 69 12 CE ÷Đĺ'(. JˇÝ.ä<i.Î
00000400 1E C1 69 24 92 C7 91 C9 2F 12 56 98 B4 05 4A B2 .Ái$’Ç‘É/.V.´.J˛
00000410 38 E0 9A C2 EC ED 4C CB F6 9C 53 F7 4E 3F D0 F6 8ŕšÂěíLËöśS÷N?Đö
00000420 CB EF D2 7C B1 C8 A3 AC B1 5D 65 DA AE 8E 50 15 ËďŇ|±ČŁ¬±]eÚ®ŽP.
00000430 31 13 7C 78 56 5C 3E FC 3F 3D ED EF 12 24 20 A4 1.|xV\>ü?=íď.$ ¤
00000440 FF C6 76 21 D7 03 D7 85 5A EE 0D 53 D7 CD 0A 02 ˙Ćv!×.×…Zî.S×Í..
00000450 E7 0A F0 8D DB CC 58 8B 51 CD 85 A2 18 A3 90 D2 ç.đŤŰĚX‹QÍ…˘.Ł.Ň
00000460 5F 93 7A 71 81 B0 14 C5 B5 B4 77 CC BD D8 65 F2 _“zq.°.Ĺµ´wĚ˝Řeň
00000470 4C B8 4E D7 ED FA 01 C4 C2 D1 39 5D 95 D1 26 C5 L¸N×íú.ÄÂŃ9]•Ń&Ĺ
00000480 4E EB 22 48 03 BE 05 42 F6 48 46 8D E9 85 D6 1A Në"H.ľ.BöHFŤé…Ö.
00000490 12 0B E6 8B 33 85 7B CD F2 AA 6E 5E 21 84 27 12 ..ć‹3…{ÍňŞn^!„'.
000004A0 4F F3 F7 55 FE 4F 33 1D BE C2 15 61 D7 F5 00 E0 Oó÷UţO3.ľÂ.a×ő.ŕ
000004B0 D6 8B 55 61 6B AA B6 C8 7D 23 4F 73 05 92 3C 6F Ö‹UakŞ¶Č}#Os.’<o
000004C0 AD D2 F1 06 11 8B 00 00 00 00 00 00 00 00 00 00 *Ňń..‹..........[/COLOR]
000004D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

Than you can hex compare stock kernel.elf and generated kernel.elf and you can see its ~the_same :)

And finaly revert these elf to sin by command:

./bin2sin kernel.elf 030000002200000000D0000000800000