[GUIDE] How To Compile Kernel & DTBO For Redmi K20 - Redmi K20 / Xiaomi Mi 9T Guides, News, & Discussio

Introduction :
I'm not an expert in kernel development, but would like to share the steps that I followed to build my kernel. If any of other kernel developers out there would like to add on some tips or correct something, please do!
Pre-requisites :
Ubuntu or any other Linux based OS
Stable Internet Connection
Patience
Step 1 : Setup Build Environment
Open the terminal and enter the following :
Code:
sudo apt-get install git ccache automake flex lzop bison \
gperf build-essential zip curl zlib1g-dev zlib1g-dev:i386 \
g++-multilib python-networkx libxml2-utils bzip2 libbz2-dev \
libbz2-1.0 libghc-bzlib-dev squashfs-tools pngcrush \
schedtool dpkg-dev liblz4-tool make optipng maven libssl-dev \
pwgen libswitch-perl policycoreutils minicom libxml-sax-base-perl \
libxml-simple-perl bc libc6-dev-i386 lib32ncurses5-dev \
x11proto-core-dev libx11-dev lib32z-dev libgl1-mesa-dev xsltproc unzip
Step 2 : Download Required Files
Download device source :
Code:
git clone --depth=1 https://github.com/MiCode/Xiaomi_Kernel_OpenSource.git -b davinci-p-oss davinci-p-oss
Download a compatible GCC toolchain (Using AOSP's GCC for this guide) :
Code:
cd davinci-p-oss
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 toolchain
Download a compatible CLANG toolchain (Using AOSP's CLANG for this guide) : Download
Move the downloaded file in the davinci-p-oss folder manually and then extract using the following command :
Code:
tar vxzf linux-x86-android-9.0.0_r48-clang-4691093.tar.gz
Download the device-tree-compiler attached below and place it in /usr/bin
Step 3 : Make device specific changes
Make these changes in the /kernel/module.c file.
If you are not familiar with github, you can check out many github guides available on XDA, for now you can just download the module.c file attached to this thread and replace the one in /kernel folder with the downloaded one!
Now, browse back to davinci-p-oss directory, and open the davinci_user_defconfig located in \arch\arm64\configs
Add the following lines :
Code:
CONFIG_BUILD_ARM64_DT_OVERLAY=y
CONFIG_MODULE_FORCE_LOAD=y
WIFI & Audio won't work if you don't make these changes, apparently Xiaomi decided to skip wlan & audio drivers in pie sources.
Step 4 : Building The Kernel
Code:
cd davinci-p-oss
rm -rf out
mkdir out
export ARCH=arm64
export SUBARCH=arm64
export DTC_EXT=dtc
make O=out ARCH=arm64 davinci_user_defconfig
PATH="${PWD}/bin:${PWD}/toolchain/bin:${PATH}" \
make -j$(nproc --all) O=out \
ARCH=arm64 \
CC=clang \
CLANG_TRIPLE=aarch64-linux-gnu- \
CROSS_COMPILE=aarch64-linux-android- | tee kernel.log
Step 5 : How To Get Help If You Encounter Errors
A kernel.log file will be generated in davinci-p-oss folder, find the line which says error.
If you can't figure out the solution, attach the kernel.log in your reply to this thread.
Step 6 : Booting The Kernel
Once you're done with Step 4, browse to /out/arch/arm64/boot & you'll find the Image.gz-dtb file (compiled zImage)
Download the anykernel template for davinci from attachments and add your Image.gz-dtb file to the archive.
Boot in TWRP, backup your stock kernel & flash the anykernel zip.
References :
Information on compiling Android kernels with Clang by nathanchance
How to compile kernel standalone by Xiaomi
Kernel Builder Virtual Machine & device specific changes by mslezak
AnyKernel3 Template by osm0sis
Wahoo Kernel Tools by frap129
Regards,
acervenky

---

Using QCom Clang To Compile Kernel [Xiaomi's Guide]
Step 1 : Setup Build Environment
Open the terminal and enter the following :
Code:
sudo apt-get install git ccache automake flex lzop bison \
gperf build-essential zip curl zlib1g-dev zlib1g-dev:i386 \
g++-multilib python-networkx libxml2-utils bzip2 libbz2-dev \
libbz2-1.0 libghc-bzlib-dev squashfs-tools pngcrush \
schedtool dpkg-dev liblz4-tool make optipng maven libssl-dev \
pwgen libswitch-perl policycoreutils minicom libxml-sax-base-perl \
libxml-simple-perl bc libc6-dev-i386 lib32ncurses5-dev \
x11proto-core-dev libx11-dev lib32z-dev libgl1-mesa-dev xsltproc unzip
Step 2 : Download Required Files
Download device source :
Code:
git clone --depth=1 https://github.com/MiCode/Xiaomi_Kernel_OpenSource.git -b davinci-p-oss davinci-p-oss
Download a compatible GCC toolchain (Using AOSP's GCC for this guide) :
Code:
cd davinci-p-oss
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 toolchain
Download the Qcom CLANG : Download
Move the downloaded file in the davinci-p-oss folder manually and then extract using the following command :
Code:
tar vxzf snapdragon-llvm-compiler-android-linux64-609.tar.gz
Download the device-tree-compiler attached below and place it in /usr/bin
Step 3 : Make device specific changes
Make these changes in the /kernel/module.c file.
If you are not familiar with github, you can check out many github guides available on XDA, for now you can just download the module.c file attached to this thread and replace the one in /kernel folder with the downloaded one!
Now, browse back to davinci-p-oss directory, and open the davinci_user_defconfig located in \arch\arm64\configs
Add the following lines :
Code:
CONFIG_BUILD_ARM64_DT_OVERLAY=y
CONFIG_MODULE_FORCE_LOAD=y
WIFI & Audio won't work if you don't make these changes, apparently Xiaomi decided to skip wlan & audio drivers in pie sources.
Step 4 : Building The Kernel
Code:
cd davinci-p-oss
rm -rf out
mkdir out
export ARCH=arm64
export SUBARCH=arm64
export DTC_EXT=dtc
export CROSS_COMPILE=${PWD}/toolchain/bin/aarch64-linux-android-
make O=out REAL_CC=${PWD}/toolchains/llvm-Snapdragon_LLVM_for_Android_6.0/prebuilt/linux-x86_64/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- davinci_user_defconfig
make -j$(nproc) O=out REAL_CC=${PWD}/toolchains/llvm-Snapdragon_LLVM_for_Android_6.0/prebuilt/linux-x86_64/bin/clang CLANG_TRIPLE=aarch64-linux-gnu- 2>&1 | tee kernel.log
Step 5 : How To Get Help If You Encounter Errors
A kernel.log file will be generated in davinci-p-oss folder, find the line which says error.
If you can't figure out the solution, attach the kernel.log in your reply to this thread.
Step 6 : Booting The Kernel
Once you're done with Step 4, browse to /out/arch/arm64/boot & you'll find the Image.gz-dtb file (compiled zImage)
Download the anykernel template for davinci from attachments and add your Image.gz-dtb file to the archive.
Boot in TWRP, backup your stock kernel & flash the anykernel zip.
This method is mentioned in Xiaomi's Wiki, you can choose any according to your preference!
Regards,
acervenky

---

How To Compile Custom DTBO
DTBO files have been used on our device primarily to change the refresh rates.
Pre-requisites :
Compiled kernel without any errors
Step 1 : Download Required Files
Download libufdt utils from this link.
Open the terminal in the downloaded file's location.
Code:
tar vxzf libufdt-master-utils.tar.gz
Step 2 : Compile dtbo.img
Code:
cd /libufdt-master-utils/src
python mkdtboimg.py create /home/user/davinci-p-oss/out/arch/arm64/boot/dtbo.img /home/user/davinci-p-oss/out/arch/arm64/boot/dts/qcom/*.dtbo
Step 3 : Flash The Compiled dtbo.img
The compiled dtbo.img file will be located in /davinci-p-oss/out/arch/arm64/boot/ (same output folder of zImage)
Backup your stock dtbo.img and flash the newly compiled dtbo.img
References :
Kernel Builder by mslezak
Regards,
acervenky

---

reserved3

---

Nice guide @acervenky
Thank you very much
----------------------------------------------
EDIT: compiled without errors

---

oddly enough I am not able to compile their kernel using this methodology. I believe it is something to do with Clang.
I can, however, compile the elementalX kernel for the Essential PH1, using both google's and uber's toolchains
https://gitlab.com/westernmass-hosting/android/elemental-x/compiler
I am going to see if I can replicate being able to compile for Mi9 using the same methology

---

I successfully compiled the kernel and dtbo using the Ubuntu VM linked in OP, but the dtbo.img is only 3MB.
When I dumped my Mi 9T's dtbo it's 32MB. Is this normal?
I compared the output from
Code:
mkdtboimg.py dump
and it seems that dt_entry_count is 24 in the compiled dtbo compared to 28 in my dumped dtbo.
I'm running the global V10.3.11.0 MIUI ROM.
Any ideas?

---

BLUuuE83 said:
I successfully compiled the kernel and dtbo using the Ubuntu VM linked in OP, but the dtbo.img is only 3MB.
When I dumped my Mi 9T's dtbo it's 32MB. Is this normal?
I compared the output from
Code:
mkdtboimg.py dump
and it seems that dt_entry_count is 24 in the compiled dtbo compared to 28 in my dumped dtbo.
I'm running the global V10.3.11.0 MIUI ROM.
Any ideas?
Click to expand...
Click to collapse
Yes it is normal.
Regards,
acervenky

---

Hi! Can you please tell me where do i find the files for GPU and CPU frequencies? Thanks!

---

acervenky said:
Yes it is normal.
Regards,
acervenky
Click to expand...
Click to collapse
Just another question if you don't mind.
What happens if I set too low display timings? I know with a computer monitor it'll just black screen but Windows will reset to defaults after 15 seconds if you don't do anything.
Will I just get a black screen meaning I brick my phone?

---

draand28 said:
Hi! Can you please tell me where do i find the files for GPU and CPU frequencies? Thanks!
Click to expand...
Click to collapse
You can't change the CPU frequencies, however to edit GPU frequencies you can edit these files:
Code:
arch/arm64/boot/dts/qcom/sm8150-gpu-v2.dtsi
arch/arm64/boot/dts/qcom/sm8150-v2.dtsi
BLUuuE83 said:
Just another question if you don't mind.
What happens if I set too low display timings? I know with a computer monitor it'll just black screen but Windows will reset to defaults after 15 seconds if you don't do anything.
Will I just get a black screen meaning I brick my phone?
Click to expand...
Click to collapse
If you set the timings too low/high they'll reset to the default values.
Regards,
acervenky

---

Hi! Thanks for answering. I have edited those frequencies but nothing changed on the phone. Still 585mhz maximum on gpu, even though I have tried different modifications (700,800,825). Even tried to add new steps above the original ones. I got the refresh rate mod working though. Also, if you can tell me the location of thermal configuration, that would be great. I have found a sm8150-thermal.dtsi file but can't figure out the actual temperatures, there are just some too low to be correct numbers.
I'll leave you with the modifications that I've made to the gpu and gpu-v2 files.
Code:
/* Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
&soc {
pil_gpu: qcom,kgsl-hyp {
compatible = "qcom,pil-tz-generic";
qcom,pas-id = <13>;
qcom,firmware-name = "a640_zap";
};
msm_bus: qcom,kgsl-busmon{
label = "kgsl-busmon";
compatible = "qcom,kgsl-busmon";
};
gpubw: qcom,gpubw {
compatible = "qcom,devbw";
governor = "bw_vbif";
qcom,src-dst-ports = <26 512>;
operating-points-v2 = <&suspendable_ddr_bw_opp_table>;
};
gpu_opp_table: gpu-opp-table {
compatible = "operating-points-v2";
opp-825000000 {
opp-hz = /bits/ 64 <825000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_TURBO_L1>;
};
opp-735000000 {
opp-hz = /bits/ 64 <735000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_TURBO_L1>;
};
opp-675000000 {
opp-hz = /bits/ 64 <675000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_NOM_L1>;
};
opp-553850000 {
opp-hz = /bits/ 64 <553850000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_NOM>;
};
opp-486460000 {
opp-hz = /bits/ 64 <486460000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS_L2>;
};
opp-379650000 {
opp-hz = /bits/ 64 <379650000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS_L1>;
};
opp-309110000 {
opp-hz = /bits/ 64 <309110000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS>;
};
opp-215000000 {
opp-hz = /bits/ 64 <215000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
};
opp-96000000 {
opp-hz = /bits/ 64 <96000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_MIN_SVS>;
};
};
msm_gpu: qcom,[email protected] {
label = "kgsl-3d0";
compatible = "qcom,kgsl-3d0", "qcom,kgsl-3d";
status = "ok";
reg = <0x2c00000 0x40000>, <0x2c61000 0x800>,
<0x6900000 0x44000>, <0x780000 0x6fff>;
reg-names = "kgsl_3d0_reg_memory", "cx_dbgc",
"qdss_gfx", "qfprom_memory";
interrupts = <0 300 0>;
interrupt-names = "kgsl_3d0_irq";
qcom,id = <0>;
qcom,chipid = <0x06040000>;
qcom,initial-pwrlevel = <5>;
qcom,gpu-quirk-secvid-set-once;
qcom,gpu-quirk-cx-gdsc;
qcom,idle-timeout = <64>; //msecs
qcom,no-nap;
qcom,highest-bank-bit = <15>;
qcom,min-access-length = <32>;
qcom,ubwc-mode = <3>;
qcom,snapshot-size = <0x200000>; //bytes
qcom,gpu-qdss-stm = <0x161c0000 0x40000>; // base addr, size
qcom,tsens-name = "tsens_tz_sensor12";
#cooling-cells = <2>;
tzone-names = "gpuss-0-usr", "gpuss-1-usr";
qcom,pm-qos-active-latency = <1000>;
qcom,l2pc-cpu-mask-latency = <1000>;
qcom,pm-qos-wakeup-latency = <100>;
clocks = <&clock_gpucc GPU_CC_CXO_CLK>,
<&clock_gcc GCC_DDRSS_GPU_AXI_CLK>,
<&clock_gcc GCC_GPU_MEMNOC_GFX_CLK>,
<&clock_gpucc GPU_CC_CX_GMU_CLK>,
<&clock_gpucc GPU_CC_AHB_CLK>,
<&clock_cpucc L3_GPU_VOTE_CLK>;
clock-names = "rbbmtimer_clk", "mem_clk",
"mem_iface_clk", "gmu_clk",
"gpu_cc_ahb", "l3_vote";
qcom,isense-clk-on-level = <1>;
/* Bus Scale Settings */
qcom,gpubw-dev = <&gpubw>;
qcom,bus-control;
qcom,msm-bus,name = "grp3d";
qcom,bus-width = <32>;
qcom,msm-bus,num-cases = <13>;
qcom,msm-bus,num-paths = <1>;
qcom,msm-bus,vectors-KBps =
<26 512 0 0>,
<26 512 0 400000>, // 1 bus=100
<26 512 0 600000>, // 2 bus=150
<26 512 0 800000>, // 3 bus=200
<26 512 0 1200000>, // 4 bus=300
<26 512 0 1648000>, // 5 bus=412
<26 512 0 2188000>, // 6 bus=547
<26 512 0 2724000>, // 7 bus=681
<26 512 0 3072000>, // 8 bus=768
<26 512 0 4068000>, // 9 bus=1017
<26 512 0 5184000>, // 10 bus=1296
<26 512 0 6220000>, // 11 bus=1555
<26 512 0 7216000>; // 12 bus=1804
/* GDSC regulator names */
regulator-names = "vddcx", "vdd";
/* GDSC oxili regulators */
vddcx-supply = <&gpu_cx_gdsc>;
vdd-supply = <&gpu_gx_gdsc>;
/* GPU OPP data */
operating-points-v2 = <&gpu_opp_table>;
/* GPU related llc slices */
cache-slice-names = "gpu", "gpuhtw";
cache-slices = <&llcc 12>, <&llcc 11>;
qcom,l3-pwrlevels {
#address-cells = <1>;
#size-cells = <0>;
compatible = "qcom,l3-pwrlevels";
qcom,[email protected] {
reg = <0>;
qcom,l3-freq = <0>;
};
qcom,l3-pwrl[email protected] {
reg = <1>;
qcom,l3-freq = <864000000>;
};
qcom,[email protected] {
reg = <2>;
qcom,l3-freq = <1344000000>;
};
};
/* GPU Mempools */
qcom,gpu-mempools {
#address-cells = <1>;
#size-cells = <0>;
compatible = "qcom,gpu-mempools";
/* 4K Page Pool configuration */
qcom,[email protected] {
reg = <0>;
qcom,mempool-page-size = <4096>;
qcom,mempool-reserved = <2048>;
qcom,mempool-allocate;
};
/* 8K Page Pool configuration */
qcom,[email protected] {
reg = <1>;
qcom,mempool-page-size = <8192>;
qcom,mempool-reserved = <1024>;
qcom,mempool-allocate;
};
/* 64K Page Pool configuration */
qcom,[email protected] {
reg = <2>;
qcom,mempool-page-size = <65536>;
qcom,mempool-reserved = <256>;
};
/* 1M Page Pool configuration */
qcom,[email protected] {
reg = <3>;
qcom,mempool-page-size = <1048576>;
qcom,mempool-reserved = <32>;
};
};
/* Power levels */
qcom,gpu-pwrlevels {
#address-cells = <1>;
#size-cells = <0>;
compatible = "qcom,gpu-pwrlevels";
qcom,[email protected] {
reg = <0>;
qcom,gpu-freq = <600000000>;
qcom,bus-freq = <12>;
qcom,bus-min = <10>;
qcom,bus-max = <12>;
};
qcom,[email protected] {
reg = <1>;
qcom,gpu-freq = <553850000>;
qcom,bus-freq = <10>;
qcom,bus-min = <9>;
qcom,bus-max = <11>;
};
qcom,[email protected] {
reg = <2>;
qcom,gpu-freq = <486460000>;
qcom,bus-freq = <9>;
qcom,bus-min = <8>;
qcom,bus-max = <10>;
};
qcom,[email protected] {
reg = <3>;
qcom,gpu-freq = <379650000>;
qcom,bus-freq = <8>;
qcom,bus-min = <7>;
qcom,bus-max = <9>;
};
qcom,[email protected] {
reg = <4>;
qcom,gpu-freq = <309110000>;
qcom,bus-freq = <5>;
qcom,bus-min = <5>;
qcom,bus-max = <7>;
};
qcom,[email protected] {
reg = <5>;
qcom,gpu-freq = <215000000>;
qcom,bus-freq = <4>;
qcom,bus-min = <3>;
qcom,bus-max = <5>;
};
qcom,[email protected] {
reg = <6>;
qcom,gpu-freq = <0>;
qcom,bus-freq = <0>;
qcom,bus-min = <0>;
qcom,bus-max = <0>;
};
};
};
kgsl_msm_iommu: qcom,[email protected] {
compatible = "qcom,kgsl-smmu-v2";
reg = <0x02CA0000 0x10000>;
/* CB5(ATOS) & CB5/6/7 are protected by HYP */
qcom,protect = <0xa0000 0xc000>;
clocks =<&clock_gcc GCC_GPU_CFG_AHB_CLK>,
<&clock_gcc GCC_DDRSS_GPU_AXI_CLK>,
<&clock_gcc GCC_GPU_MEMNOC_GFX_CLK>;
clock-names = "iface_clk", "mem_clk", "mem_iface_clk";
qcom,secure_align_mask = <0xfff>;
qcom,retention;
qcom,hyp_secure_alloc;
gfx3d_user: gfx3d_user {
compatible = "qcom,smmu-kgsl-cb";
label = "gfx3d_user";
iommus = <&kgsl_smmu 0x0 0x401>;
qcom,gpu-offset = <0xa8000>;
};
gfx3d_secure: gfx3d_secure {
compatible = "qcom,smmu-kgsl-cb";
label = "gfx3d_secure";
iommus = <&kgsl_smmu 0x2 0x400>;
};
};
gmu: qcom,[email protected] {
label = "kgsl-gmu";
compatible = "qcom,gpu-gmu";
reg = <0x2c6a000 0x30000>,
<0xb280000 0x10000>,
<0xb480000 0x10000>;
reg-names = "kgsl_gmu_reg",
"kgsl_gmu_pdc_cfg",
"kgsl_gmu_pdc_seq";
interrupts = <0 304 0>, <0 305 0>;
interrupt-names = "kgsl_hfi_irq", "kgsl_gmu_irq";
qcom,msm-bus,name = "cnoc";
qcom,msm-bus,num-cases = <2>;
qcom,msm-bus,num-paths = <1>;
qcom,msm-bus,vectors-KBps =
<26 10036 0 0>, // CNOC off
<26 10036 0 100>; // CNOC on
regulator-names = "vddcx", "vdd";
vddcx-supply = <&gpu_cx_gdsc>;
vdd-supply = <&gpu_gx_gdsc>;
clocks = <&clock_gpucc GPU_CC_CX_GMU_CLK>,
<&clock_gpucc GPU_CC_CXO_CLK>,
<&clock_gcc GCC_DDRSS_GPU_AXI_CLK>,
<&clock_gcc GCC_GPU_MEMNOC_GFX_CLK>,
<&clock_gpucc GPU_CC_AHB_CLK>;
clock-names = "gmu_clk", "cxo_clk", "axi_clk",
"memnoc_clk", "gpu_cc_ahb";
/* AOP mailbox for sending ACD enable and disable messages */
mboxes = <&qmp_aop 0>;
mbox-names = "aop";
qcom,gmu-pwrlevels {
#address-cells = <1>;
#size-cells = <0>;
compatible = "qcom,gmu-pwrlevels";
/* GMU power levels must go from lowest to highest */
qcom,[email protected] {
reg = <0>;
qcom,gmu-freq = <0>;
};
qcom,[email protected] {
reg = <1>;
qcom,gmu-freq = <200000000>;
};
};
gmu_user: gmu_user {
compatible = "qcom,smmu-gmu-user-cb";
iommus = <&kgsl_smmu 0x4 0x400>;
};
gmu_kernel: gmu_kernel {
compatible = "qcom,smmu-gmu-kernel-cb";
iommus = <&kgsl_smmu 0x5 0x400>;
};
};
};
Code:
/* Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
&soc {
gpu_opp_table_v2: gpu_opp_table_v2 {
compatible = "operating-points-v2";
opp-825000000 {
opp-hz = /bits/ 64 <825000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_TURBO_L1>;
};
opp-735000000 {
opp-hz = /bits/ 64 <735000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_TURBO_L1>;
};
opp-675000000 {
opp-hz = /bits/ 64 <675000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_NOM_L1>;
};
opp-585000000 {
opp-hz = /bits/ 64 <585000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_NOM>;
};
opp-499200000 {
opp-hz = /bits/ 64 <499200000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS_L2>;
};
opp-427000000 {
opp-hz = /bits/ 64 <427000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS_L1>;
};
opp-345000000 {
opp-hz = /bits/ 64 <345000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_SVS>;
};
opp-257000000 {
opp-hz = /bits/ 64 <257000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_LOW_SVS>;
};
opp-96000000 {
opp-hz = /bits/ 64 <96000000>;
opp-microvolt = <RPMH_REGULATOR_LEVEL_MIN_SVS>;
};
};
};

---

acervenky said:
How To Compile Custom DTBO
DTBO files have been used on our device primarily to change the refresh rates.
Pre-requisites :
Compiled kernel without any errors
Step 1 : Download Required Files
Download libufdt utils from this link.
Open the terminal in the downloaded file's location.
Code:
tar vxzf libufdt-master-utils.tar.gz
Step 2 : Compile dtbo.img
Code:
cd /libufdt-master-utils/src
python mkdtboimg.py create /home/user/davinci-p-oss/out/arch/arm64/boot/dtbo.img /home/user/davinci-p-oss/out/arch/arm64/boot/dts/qcom/*.dtbo
Step 3 : Flash The Compiled dtbo.img
The compiled dtbo.img file will be located in /davinci-p-oss/out/arch/arm64/boot/ (same output folder of zImage)
Backup your stock dtbo.img and flash the newly compiled dtbo.img
References :
Kernel Builder by mslezak
Regards,
acervenky
Click to expand...
Click to collapse
What is the DTBO ? For what is it and why does it need changes ?

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I followed instruction to build on Ubuntu 20.04 and got following console output
make[1]: Entering directory '/home/android/sources/k/davinci-p-oss/out'
../scripts/gcc-version.sh: line 32: printf: Is: invalid number
../scripts/gcc-version.sh: line 32: printf: your: invalid number
../scripts/gcc-version.sh: line 32: printf: PATH: invalid number
../scripts/gcc-version.sh: line 32: printf: set: invalid number
../scripts/gcc-version.sh: line 32: printf: correctly?: invalid number
../scripts/gcc-version.sh: line 32: printf: Is: invalid number
../scripts/gcc-version.sh: line 32: printf: your: invalid number
../scripts/gcc-version.sh: line 32: printf: PATH: invalid number
../scripts/gcc-version.sh: line 32: printf: set: invalid number
../scripts/gcc-version.sh: line 32: printf: correctly?: invalid number
/bin/sh: 1: [: 0000: unexpected operator
HOSTCC scripts/basic/fixdep
GEN ./Makefile
HOSTCC scripts/kconfig/conf.o
SHIPPED scripts/kconfig/zconf.tab.c
SHIPPED scripts/kconfig/zconf.lex.c
HOSTCC scripts/kconfig/zconf.tab.o
HOSTLD scripts/kconfig/conf
scripts/kconfig/conf --silentoldconfig Kconfig
***
*** Configuration file ".config" not found!
***
*** Please run some configurator (e.g. "make oldconfig" or
*** "make menuconfig" or "make xconfig").
***
make[4]: *** [../scripts/kconfig/Makefile:40: silentoldconfig] Error 1
make[3]: *** [../Makefile:529: silentoldconfig] Error 2
make[2]: Nothing to be done for '/home/android/sources/k/davinci-p-oss/out'.
kernel.log
make[1]: Entering directory '/home/android/sources/k/davinci-p-oss/out'
GEN ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
make[1]: Nothing to be done for '/home/android/sources/k/davinci-p-oss/out'.
make[1]: Leaving directory '/home/android/sources/k/davinci-p-oss/out'
#### build completed successfully (21 seconds) ####
Any advice on how to fix it?
Best Regards,

---

I found issues. Compile successfully with default .bashrc and Ubuntu 18.04

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VD171 said:
What is the DTBO ? For what is it and why does it need changes ?
Click to expand...
Click to collapse
DTB=Device Tree Blobs
From Oreo, device hardware blobs load outside of kernel.
When you turn on your device, these components load step by step:
1- first ramdisk. Say how OS may load. Set permission for each partition.
2- second kernel boot. Say any hardware how to communicate with operation system.
3- dtb/dtbo partition load. Help any hardware work property.
Without dtb, your boot.img not booted or boot on old dtbs.img on your phone. (If you lot of changes on your kernel codes, old blobs not enough for standard performance)
For more info see:
https://source.android.com/devices/architecture/dto/partitions

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GenomeX said:
DTB=Device Tree Blobs
From Oreo, device hardware blobs load outside of kernel.
When you turn on your device, these components load step by step:
1- first ramdisk. Say how OS may load. Set permission for each partition.
2- second kernel boot. Say any hardware how to communicate with operation system.
3- dtb/dtbo partition load. Help any hardware work property.
Without dtb, your boot.img not booted or boot on old dtbs.img on your phone. (If you lot of changes on your kernel codes, old blobs not enough for standard performance)
For more info see:
https://source.android.com/devices/architecture/dto/partitions
Click to expand...
Click to collapse
With all the details it was very easy to understand what it is and how DTB/DTBO works.
Thank you very much for an amazing answer.

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How to make dtbo.img to dts

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acervenky said:
Introduction :
I'm not an expert in kernel development, but would like to share the steps that I followed to build my kernel. If any of other kernel developers out there would like to add on some tips or correct something, please do!
Pre-requisites :
Ubuntu or any other Linux based OS
Stable Internet Connection
Patience
Step 1 : Setup Build Environment
Open the terminal and enter the following :
Code:
sudo apt-get install git ccache automake flex lzop bison \
gperf build-essential zip curl zlib1g-dev zlib1g-dev:i386 \
g++-multilib python-networkx libxml2-utils bzip2 libbz2-dev \
libbz2-1.0 libghc-bzlib-dev squashfs-tools pngcrush \
schedtool dpkg-dev liblz4-tool make optipng maven libssl-dev \
pwgen libswitch-perl policycoreutils minicom libxml-sax-base-perl \
libxml-simple-perl bc libc6-dev-i386 lib32ncurses5-dev \
x11proto-core-dev libx11-dev lib32z-dev libgl1-mesa-dev xsltproc unzip
Step 2 : Download Required Files
Download device source :
Code:
git clone --depth=1 https://github.com/MiCode/Xiaomi_Kernel_OpenSource.git -b davinci-p-oss davinci-p-oss
Download a compatible GCC toolchain (Using AOSP's GCC for this guide) :
Code:
cd davinci-p-oss
git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9 toolchain
Download a compatible CLANG toolchain (Using AOSP's CLANG for this guide) : Download
Move the downloaded file in the davinci-p-oss folder manually and then extract using the following command :
Code:
tar vxzf linux-x86-android-9.0.0_r48-clang-4691093.tar.gz
Download the device-tree-compiler attached below and place it in /usr/bin
Step 3 : Make device specific changes
Make these changes in the /kernel/module.c file.
If you are not familiar with github, you can check out many github guides available on XDA, for now you can just download the module.c file attached to this thread and replace the one in /kernel folder with the downloaded one!
Now, browse back to davinci-p-oss directory, and open the davinci_user_defconfig located in \arch\arm64\configs
Add the following lines :
Code:
CONFIG_BUILD_ARM64_DT_OVERLAY=y
CONFIG_MODULE_FORCE_LOAD=y
WIFI & Audio won't work if you don't make these changes, apparently Xiaomi decided to skip wlan & audio drivers in pie sources.
Step 4 : Building The Kernel
Code:
cd davinci-p-oss
rm -rf out
mkdir out
export ARCH=arm64
export SUBARCH=arm64
export DTC_EXT=dtc
make O=out ARCH=arm64 davinci_user_defconfig
PATH="${PWD}/bin:${PWD}/toolchain/bin:${PATH}" \
make -j$(nproc --all) O=out \
ARCH=arm64 \
CC=clang \
CLANG_TRIPLE=aarch64-linux-gnu- \
CROSS_COMPILE=aarch64-linux-android- | tee kernel.log
Step 5 : How To Get Help If You Encounter Errors
A kernel.log file will be generated in davinci-p-oss folder, find the line which says error.
If you can't figure out the solution, attach the kernel.log in your reply to this thread.
Step 6 : Booting The Kernel
Once you're done with Step 4, browse to /out/arch/arm64/boot & you'll find the Image.gz-dtb file (compiled zImage)
Download the anykernel template for davinci from attachments and add your Image.gz-dtb file to the archive.
Boot in TWRP, backup your stock kernel & flash the anykernel zip.
References :
Information on compiling Android kernels with Clang by nathanchance
How to compile kernel standalone by Xiaomi
Kernel Builder Virtual Machine & device specific changes by mslezak
AnyKernel3 Template by osm0sis
Wahoo Kernel Tools by frap129
Regards,
acervenky
Click to expand...
Click to collapse