SDK Layout and Build Environment
SDK Directories
Common Tina Linux 5.0 directories:
brandy/ BOOT0, U-Boot, and boot tools
bsp/ Linux BSP device trees, drivers, and headers
build/ SDK build and packaging scripts
device/config/chips/v821/ V821 board-level configuration
kernel/linux-5.4-ansc/ Upstream-style Linux kernel tree
openwrt/ Root filesystem and user-space packages
platform/allwinner/ MPP and platform applications
prebuilt/ Host tools and cross toolchains
rtos/ RTOS source for the RISC-V MCU
out/ Build and package output
Initialize the Environment
All shortcut commands depend on the environment script:
cd <sdk-root>
source build/envsetup.sh
lunch
The X821 manual uses v821-aitoy-tina as the board example. A delivered SDK may add storage, UART, or fast-boot suffixes; treat the current lunch list and README.txt as authoritative.
Common Shortcuts
| Command | Purpose |
|---|---|
croot | Return to the SDK root |
cconfigs | Open the board BSP configuration directory |
cplat | Open the OpenWrt board directory |
cboot / cboot0 | Open the U-Boot/BOOT0 directories |
cbsp | Open the BSP directory |
crtos | Open the RTOS directory |
cout | Open the selected board output directory |
make menuconfig | Configure Tina packages |
make kernel_menuconfig | Configure the Linux kernel |
mrtos menuconfig | Configure the RTOS |
m / make | Build the SDK |
pack | Package firmware |
Parallel Build Jobs
nproc
m -j$(nproc)
Increasing -j does not provide linear speedup when memory, disk I/O, or serial build steps are the bottleneck. For stable builds, start near the number of physical cores and measure.