6939b5cacf
The Linux environment for all boards using the Canaan Kendryte K210 SoC can be built with the same process, using configurations that differ only by the device tree used for the build. This patch add the shared configurations, rootfs overlay and scripts used for all K210-based boards. Since the K210 SoC only has 8 MB of SRAM, a special busybox configuration and rootfs overlay are added to save memory at runtime: * For configurations using direct kernel boot (no boot loader), the default busybox configuration busybox-minimal.config is modified using the fragment file board/canaan/k210-soc/busybox-tiny.config. This reduces the size of the busybox executable to save memory when executing shell commands. * Busybox init system is not used and a special init scripts is provided using the rootfs_overlay root file system overlay. This init script simply mounts devtmpfs, /proc and /sys, and exec an interactive shell after printing a logo. This avoids (1) boot failures due to large memory allocations by the regular busybox init system (these allocations fail on the K210 for lack of enough memory) and avoids (2) keeping the init process sleeping in the background (wasted memory). The board/canaan/k210-soc/busybox-tiny.config and the rootfs overlay files in board/canaan/k210-soc/rootfs_overlay are used for all Canaan K210 SoC based boards. For board configurations booting using the U-Boot boot loader, a common set of linux kernel configuration parameters is provided by the file board/canaan/k210-soc/linux-sdcard.config. In addition, the post build script board/canaan/k210-soc/post-build.sh file and U-Boot image generation configuration file board/canaan/k210-soc/genimage.cfg are provided. The post-build script creates a generic "k210.dtb" symlink to the compiled device tree file for the target board. This symlink is used by the genimage.cfg configuration, making this file common for all boards. Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
42 lines
1.2 KiB
Bash
Executable File
42 lines
1.2 KiB
Bash
Executable File
#!/bin/sh
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# This script replaces the default busybox init process to avoid having that
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# process staying alive and sleeping in the background, (uselessly) consuming
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# precious memory.
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# Mount procfs and sysfs
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/bin/mount -t proc proc /proc
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/bin/mount -t sysfs sysfs /sys
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# When the kernel is directly booted, devtmpfs is not automatically mounted.
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# Manually mount it if needed.
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devmnt=$(mount | grep -c devtmpfs)
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if [ ${devmnt} -eq 0 ]; then
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/bin/mount -t devtmpfs devtmpfs /dev
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fi
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# Use the /dev/console device node from devtmpfs if possible to not
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# confuse glibc's ttyname_r().
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# This may fail (E.G. booted with console=), and errors from exec will
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# terminate the shell, so use a subshell for the test
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if (exec 0</dev/console) 2>/dev/null; then
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exec 0</dev/console
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exec 1>/dev/console
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exec 2>/dev/console
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fi
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# Clear memory to reduce page fragmentation
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echo 3 > /proc/sys/vm/drop_caches
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# Print a fun logo :)
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echo " __ _"
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echo " / / (_) ____ _ _ __ __"
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echo " / / | || _ \\ | | | |\\ \\/ /"
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echo " / /___| || | | || |_| | > < "
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echo " /_____/|_||_| |_| \\____|/_/\\_\\"
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echo " 64-bits RISC-V Kendryte K210 NOMMU"
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echo ""
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# Finally, let's start an interactive shell
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exec /bin/sh
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