Building
bedrock[RTOS] uses chorus as its build system. Chorus is included as a git submodule at 3rd/tools/chorus.
Prerequisites
arm-none-eabi-gcctoolchainqemu-system-arm(for running on QEMU)- Go compiler (to build chorus, if not using a prebuilt binary)
Installing on Arch Linux
sudo pacman -S arm-none-eabi-gcc arm-none-eabi-newlib qemu-system-armBuilding Chorus
cd 3rd/tools/chorus
go build -o chorus .
sudo cp chorus /usr/local/bin/Build
From the project root:
chorusThis produces:
| Artifact | Description |
|---|---|
libbedrock_kernel.a | Kernel: scheduler, tasks, time, IPC |
libbedrock_hal.a | HAL: timer, context switch, UART, startup |
libbedrock_lib.a | Library: static pool allocator |
bedrock_example.elf | Example application linked with all libraries |
Clean
chorus cleanRemoves all *.o, *.a, *.elf, *.bin files.
Running on QEMU
qemu-system-arm -M lm3s6965evb -nographic -kernel bedrock_example.elfPress Ctrl+A, then X to exit QEMU.
Build Configuration
The chorus.build file defines variables and compile-time configuration.
Variables
| Variable | Description |
|---|---|
CC | C compiler (arm-none-eabi-gcc) |
AR | Archiver (arm-none-eabi-ar) |
OBJCOPY | Object copy tool (arm-none-eabi-objcopy) |
CFLAGS | Compiler flags (C11, Cortex-M3, thumb, includes, config defines) |
LDFLAGS | Linker flags (nostdlib, gc-sections, linker script) |
Compile-Time Configuration
Configuration values are passed as -D flags in CFLAGS:
| Define | Default | Description |
|---|---|---|
CONFIG_MAX_TASKS | 16 | Maximum number of tasks |
CONFIG_NUM_PRIORITIES | 8 | Number of priority levels |
CONFIG_DEFAULT_STACK_SIZE | 1024 | Default stack size in bytes |
CONFIG_TICKLESS | 1 | Enable tickless operation |
BR_HAL_SYS_CLOCK_HZ | 16000000 | System clock frequency |
To change a value, edit the CFLAGS line in chorus.build.
Link Order
The linker processes libraries left-to-right. The link command places project libraries before system libraries:
main.o -lbedrock_kernel -lbedrock_hal -lbedrock_lib -lc -lnosys -lgccThis ensures that references from kernel/HAL code to memcpy, memset etc. are resolved by -lc.