[Galaxy S III Mini Android Development] 1N4148:
/sys/kernel/liveopp/arm_step10

In this file you'll find 2 parameters:

Varm & Vbbx

Varm is the voltage applied to the ARM core which is already at max level. Only parameter left for playing around with is Vbbx, which is (as far as I know from CMOS technology) the bias voltage for switching the transistors in the chip. The higher the clock frequency the more swing they need for fast switching.

As you can see from the source code of the regulator chip, the 1st digit in the Vbbx hex value is the vbbp part of the struct, the 2nd is the vbbn part.

Default value for frequencies up to 1000 MHz is 0xDB which translates into -300/+300 according to the source (cannot measure without disassembling my device ;)). For 1100/1200 I have the CroPol defaults values 0xCF in my kernel, which translates into -400/+400 & -100/+400. If I use 0xCF as Vbbx for 1200 MHz my device's rebooting. Imho you can try every combination from -0/+0 to -400/+400. 25 attempts left :)

/* AB8500 device - Vbbp_vsel and Vbbn_sel in 100mV steps */
static const struct regulator_volt_range ab8500_vbbp_vsel[] = {
{ {0x00, 0}, {0x10, 100000}, {0x40, 400000} },
{ {0x50, 400000}, {0x10, 0}, {0x70, 400000} },
{ {0x80, -400000}, {0x10, 0}, {0xb0, -400000} },
{ {0xc0, -400000}, {0x10, 100000}, {0xf0, -100000} },
};

static const struct regulator_volt_range ab8500_vbbn_vsel[] = {
{ {0x00, 0}, {0x01, -100000}, {0x04, -400000} },
{ {0x05, -400000}, {0x01, 0}, {0x07, -400000} },
{ {0x08, 0}, {0x01, 100000}, {0x0c, 400000} },
{ {0x0d, 400000}, {0x01, 0}, {0x0f, 400000} },
};

---------- Post added at 07:24 PM ---------- Previous post was at 07:17 PM ----------

No need to remount /system as rw as the files are under /sys, which is root writable. I'm using ES File Explorer, but you can also use adb.

e.g.

C:\>adb shell

$ su

# cat /sys/kernel/liveopp/arm_step10 [checking for the right frequency]

# cat 0x8f >/sys/kernel/liveopp/arm_step10 [set new Vbbx]

or to find out under-/overvolting

Increase Varm voltage one step for a frequency:

#cat varm+ >/sys/kernel/liveopp/arm_stepXX

Decrease Varm voltage one step for a frequency:

#cat varm- >/sys/kernel/liveopp/arm_stepXX

Maybe there's a rapid apk coder around here who makes a small app for changing the liveop values? I'm to dumb for that, didn't even tried to make a 'Hello world' app ;)

---------- Post added at 07:37 PM ---------- Previous post was at 07:24 PM ----------

Ok, for the hardcore tweakers among the crowd here, there is even more to play with.

For every arm_stepXX there are 5 parameters which can changed on the fly:

// changing pll

#cat pll=YYYY >/sys/kernel/liveopp/arm_stepXX

// changing varm (values > 0x35 won't increase the voltage any further as this is obviously a regulator limit)

#cat varm=YY >/sys/kernel/liveopp/arm_stepXX

// changing vbbx

#cat varm=YY >/sys/kernel/liveopp/arm_stepXX

// changing ape opp (valid values 25, 50 & 100)

#cat apeopp=YY >/sys/kernel/liveopp/arm_stepXX

// changing ddr opp (valid values are 25, 50 & 100)

#cat ddropp=YY >/sys/kernel/liveopp/arm_stepXX

Have a look at the huge frequency table from ChronoMonochromes kernel:

static struct liveopp_arm_table liveopp_arm[] = {
#ifndef CONFIG_LIVEOPP_EXTREMELY_UVED_TABLE
//	| CLK | PLL | VDD | VBB | DDR | APE |
{ 46000, 46080, 0x00050106, 0x18, 0xDB, 25, 25},
{ 69000, 69120, 0x00050109, 0x18, 0xDB, 25, 25},
{ 92000, 92160, 0x0005010c, 0x18, 0xDB, 25, 25},
{ 115000, 115200, 0x0005010f, 0x18, 0xDB, 25, 25},
{ 140000, 138240, 0x00050112, 0x18, 0xDB, 25, 25},
{ 160000, 161280, 0x00050115, 0x18, 0xDB, 25, 25},
{ 184000, 184320, 0x00050118, 0x18, 0xDB, 25, 25},
{ 200000, 199680, 0x0005011a, 0x18, 0xDB, 25, 25},
{ 230000, 230400, 0x0005011e, 0x18, 0xDB, 25, 25},
{ 253000, 253440, 0x00050121, 0x18, 0xDB, 25, 25},
{ 276000, 276480, 0x00050124, 0x18, 0xDB, 25, 25},
{ 300000, 299520, 0x00050127, 0x18, 0xDB, 25, 25},
{ 322000, 322560, 0x0005012a, 0x18, 0xDB, 25, 25},
{ 345000, 345600, 0x0005012d, 0x18, 0xDB, 25, 25},
{ 369000, 368640, 0x00050130, 0x18, 0xDB, 25, 25},
{ 400000, 399360, 0x00050134, 0x18, 0xDB, 25, 50},
{ 438000, 437760, 0x00050139, 0x20, 0xDB, 25, 50},
{ 460000, 460800, 0x0005013c, 0x20, 0xDB, 25, 50},
{ 484000, 483840, 0x0005013f, 0x20, 0xDB, 25, 50},
{ 507000, 506880, 0x00050142, 0x20, 0xDB, 25, 50},
{ 530000, 529920, 0x00050145, 0x20, 0xDB, 25, 50},
{ 553000, 552960, 0x00050148, 0x20, 0xDB, 25, 50},
{ 576000, 576000, 0x0005014b, 0x20, 0xDB, 25, 50},
{ 600000, 599040, 0x0005014e, 0x20, 0xDB, 25, 50},
{ 622000, 622080, 0x00050151, 0x24, 0xDB, 50, 50},
{ 645000, 645120, 0x00050154, 0x24, 0xDB, 50, 50},
{ 668000, 668160, 0x00050157, 0x24, 0xDB, 50, 50},
{ 691000, 691200, 0x0005015a, 0x24, 0xDB, 50, 50},
{ 714000, 714240, 0x0005015d, 0x24, 0xDB, 50, 50},
{ 737000, 737280, 0x00050160, 0x24, 0xDB, 50, 50},
{ 760000, 760320, 0x00050163, 0x24, 0xDB, 50, 50},
{ 783000, 783360, 0x00050166, 0x24, 0xDB, 50, 50},
{ 800000, 798720, 0x00050168, 0x24, 0xDB, 100, 50},
{ 830000, 829440, 0x0005016c, 0x2F, 0xDB, 100, 50},
{ 852000, 852480, 0x0005016f, 0x2F, 0xDB, 100, 50},
{ 875000, 875520, 0x00050172, 0x2F, 0xDB, 100, 50},
{ 900000, 898560, 0x00050175, 0x2F, 0xDB, 100, 50},
{ 922000, 921600, 0x00050178, 0x2F, 0xDB, 100, 100},
{ 945000, 944640, 0x0005017b, 0x2F, 0xDB, 100, 100},
{ 968000, 967680, 0x0005017e, 0x2F, 0xDB, 100, 100},
{ 1000000, 998400, 0x00050182, 0x2F, 0xDB, 100, 100},
{ 1037000, 1036800, 0x00050187, 0x32, 0xDB, 100, 100},
{ 1060000, 1059840, 0x0005018a, 0x33, 0x8F, 100, 100},
{ 1083000, 1082880, 0x0005018d, 0x35, 0x8F, 100, 100},
{ 1106000, 1105920, 0x00050190, 0x36, 0x8F, 100, 100},
{ 1129000, 1128960, 0x00050193, 0x36, 0x8F, 100, 100},
{ 1150000, 1152000, 0x00050196, 0x36, 0x8F, 100, 100},
{ 1175000, 1175040, 0x00050199, 0x36, 0x8F, 100, 100},
{ 1200000, 1198080, 0x0005019c, 0x37, 0x8F, 100, 100},
{ 1222000, 1221120, 0x0005019f, 0x39, 0x8F, 100, 100},
{ 1244000, 1244160, 0x000501a2, 0x39, 0x8F, 100, 100},
#else
{ 46000, 46080, 0x00050106, 0x05, 0xDB, 25, 25},
{ 69000, 69120, 0x00050109, 0x05, 0xDB, 25, 25},
{ 92000, 92160, 0x0005010c, 0x05, 0xDB, 25, 25},
{ 115000, 115200, 0x0005010f, 0x07, 0xDB, 25, 25},
{ 140000, 138240, 0x00050112, 0x09, 0xDB, 25, 25},
{ 160000, 161280, 0x00050115, 0x09, 0xDB, 25, 25},
{ 184000, 184320, 0x00050118, 0x09, 0xDB, 25, 25},
{ 200000, 199680, 0x0005011a, 0x09, 0xDB, 25, 25},
{ 230000, 230400, 0x0005011e, 0x09, 0xDB, 25, 25},
{ 253000, 253440, 0x00050121, 0x11, 0xDB, 25, 25},
{ 276000, 276480, 0x00050124, 0x11, 0xDB, 25, 25},
{ 300000, 299520, 0x00050127, 0x11, 0xDB, 25, 25},
{ 322000, 322560, 0x0005012a, 0x11, 0xDB, 25, 25},
{ 345000, 345600, 0x0005012d, 0x12, 0xDB, 25, 25},
{ 369000, 368640, 0x00050130, 0x12, 0xDB, 25, 25},
{ 400000, 399360, 0x00050134, 0x12, 0xDB, 25, 50},
{ 438000, 437760, 0x00050139, 0x13, 0xDB, 25, 50},
{ 460000, 460800, 0x0005013c, 0x13, 0xDB, 25, 50},
{ 484000, 483840, 0x0005013f, 0x14, 0xDB, 25, 50},
{ 507000, 506880, 0x00050142, 0x14, 0xDB, 25, 50},
{ 530000, 529920, 0x00050145, 0x15, 0xDB, 25, 50},
{ 553000, 552960, 0x00050148, 0x16, 0xDB, 25, 50},
{ 576000, 576000, 0x0005014b, 0x18, 0xDB, 25, 50},
{ 600000, 599040, 0x0005014e, 0x19, 0xDB, 25, 50},
{ 622000, 622080, 0x00050151, 0x1B, 0xDB, 50, 50},
{ 645000, 645120, 0x00050154, 0x1C, 0xDB, 50, 50},
{ 668000, 668160, 0x00050157, 0x1D, 0xDB, 50, 50},
{ 691000, 691200, 0x0005015a, 0x1D, 0xDB, 50, 50},
{ 714000, 714240, 0x0005015d, 0x1D, 0xDB, 50, 50},
{ 737000, 737280, 0x00050160, 0x1F, 0xDB, 50, 50},
{ 760000, 760320, 0x00050163, 0x1F, 0xDB, 50, 50},
{ 783000, 783360, 0x00050166, 0x20, 0xDB, 50, 50},
{ 800000, 798720, 0x00050168, 0x20, 0xDB, 100, 50},
{ 830000, 829440, 0x0005016c, 0x23, 0xDB, 100, 50},
{ 852000, 852480, 0x0005016f, 0x24, 0xDB, 100, 50},
{ 875000, 875520, 0x00050172, 0x26, 0xDB, 100, 50},
{ 900000, 898560, 0x00050175, 0x28, 0xDB, 100, 50},
{ 922000, 921600, 0x00050178, 0x29, 0xDB, 100, 100},
{ 945000, 944640, 0x0005017b, 0x2B, 0xDB, 100, 100},
{ 968000, 967680, 0x0005017e, 0x2B, 0xDB, 100, 100},
{ 1000000, 998400, 0x00050182, 0x2D, 0xDB, 100, 100},
{ 1037000, 1036800, 0x00050187, 0x2F, 0xDB, 100, 100},
{ 1060000, 1059840, 0x0005018a, 0x30, 0x8F, 100, 100},
{ 1083000, 1082880, 0x0005018d, 0x31, 0x8F, 100, 100},
{ 1106000, 1105920, 0x00050190, 0x32, 0x8F, 100, 100},
{ 1129000, 1128960, 0x00050193, 0x34, 0x8F, 100, 100},
{ 1150000, 1152000, 0x00050196, 0x35, 0x8F, 100, 100},
{ 1175000, 1175040, 0x00050199, 0x36, 0x8F, 100, 100},
{ 1200000, 1198080, 0x0005019c, 0x36, 0x8F, 100, 100},
{ 1222000, 1221120, 0x0005019f, 0x38, 0x8F, 100, 100},
{ 1244000, 1244160, 0x000501a2, 0x39, 0x8F, 100, 100},
#endif
};