linux source for raspberry pi taken from https://github.com/raspberrypi/linux/tree/master and modified to add realtime schedulers

Environment Setup

taken from

Burn Raspbian image on SDCAR of the raspberry PI

download from Raspberry website and follow their tutorial to burn a image

INSTALL TOOLCHAIN

Use the following command to install the toolchain:

git clone https://github.com/raspberrypi/tools

You can then copy the /tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64 directory to a common location (like ~/bin), and add /tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin to your $PATH in the .bashrc in your home directory (Add this line

export PATH=$PATH:PATH_TO_TOOLS_FOLDER/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin

to the end of your ~/.bashrc)

Build Kernel

clone the repo and then

in linux/BUILD_SCRIPTS run

./1_Build_rPi.sh

to build (might take a while)

and then use

lsblk #to see find the sdcard partitions

and then export your path to be visible for ./3_Enable_SSH.sh

export RPI_BOOT_PARTITION=#dev/sd?? #boot partition

export RPI_ROOT_PARTITION=#dev/sd?? #root partition

and then use

./2_Mount.sh

./3_Enable_SSH.sh

you should also export

export ARM_GCC_PATH_PREFIX=PATH_TO_TOOLCHAIN/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf-

for:

./4_Install_rPi.sh

to install the kernel

Modifications

./kernel/sched/rt.c:2325:#if defined(CONFIG_CISTER_RT_SCHEDULERS) ./kernel/sched/core.c:3997: #ifdef CONFIG_CISTER_RT_SCHEDULERS ./kernel/sched/core.c:7614:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./kernel/sched/sched.h:20:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./kernel/sched/sched.h:136:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./kernel/sched/sched.h:148:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./kernel/sched/sched.h:651:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./include/config/auto.conf:312:CONFIG_CISTER_RT_SCHEDULERS=y ./include/uapi/linux/sched.h:43:#if defined(CONFIG_CISTER_RT_SCHEDULERS) ./include/generated/autoconf.h:314:#define CONFIG_CISTER_RT_SCHEDULERS 1 ./include/linux/sched.h:65:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./include/linux/sched.h:1527:#ifdef CONFIG_CISTER_RT_SCHEDULERS ./include/uapi/linux/sched.h:44 ./arch/arm/include/uapi/asm/unistd.h:66:#define __NR_cister_set_task_rd (__NR_SYSCALL_BASE+ 32) ./arch/arm/kernel/calls.S:49: CALL(sys_cister_set_rt_subscheduler_and_params)

Syscalls

decimal: 7 sys_cister_tracing(int boolean1or0) 31 sys_cister_set_task_id(int custom_id) 32 sys_cister_set_rt_subscheduler_and_params(int rt_subscheduler, unsigned long subscheduler_parameter_lower_4_bytes, unsigned long subscheduler_parameter_higher_4_bytes) //rt_subscheduler is 0, 1 or 2: EDF, DM, RM respectively //subscheduler_parameter is a 8 byte unsigned long long //it should be relative deadline for EDF and DM, and period for RM

#define __NR_cister_tracing (__NR_SYSCALL_BASE+ 7) #define __NR_cister_set_task_id (__NR_SYSCALL_BASE+ 31) #define __NR_cister_set_rt_subscheduler_and_params (__NR_SYSCALL_BASE+ 32)

Scheduler Numbers

SCHED_RTS 7

Implemented Real-Time Schedulers

Earliest Deadline First (EDF_INDEX = 0) 0 based on absolute deadline (d) which is updated on an enqueue Deadline Monotonic (DM_INDEX = 1) based on relative deadline (D) Rate Monotonic (RM_INDEX = 2) based on Period (T)

NOTES