Hi,
I was playing around with qemu_arm and qemu_arm64 and noticed some images using the distro bootcmd infrastructure failed to boot there due to the buffer for kernel command line arguments (which is determined by CONFIG_SYS_CBSIZE) was too small. I found this odd given the images worked on some other boards but turns out all of them bump it up from the default of 256:
include/configs/tegra-common.h:#define CONFIG_SYS_CBSIZE (1024 * 2) /* Console I/O Buffer Size */ include/configs/sunxi-common.h:#define CONFIG_SYS_CBSIZE 1024 /* Console I/O Buffer Size */ include/configs/mx6_common.h:#define CONFIG_SYS_CBSIZE 512 include/configs/rpi.h:#define CONFIG_SYS_CBSIZE 1024
For 2018.03 I'll send a patch to increase it for qemu-arm too but I think for the next release we should increase default (in config_fallbacks.h) so that the user experience is consistent on all boards. But, I wonder how safe it is to increase it for these boards low on RAM and stack? Should it perhaps be increased only for boards with CONFIG_DISTRO_DEFAULTS that are expected to have enough resources for everything and the kitchen sink? Or decoupling the kernel command line length from CONFIG_SYS_CBSIZE and using malloc()? Other ideas?
Thanks, - Tuomas