I built the kernel from https://github.com/khadas/linux so assume latest version. I turned off CMA using both menuconfig and by editing the kvim_defconfig file, by commenting out CONFIG_CMA=y and CONFIG_DMA_CMA=y, tried the combinations of these one by one and both together and get the same error.
first error is bypass_4K being an unused variable and generates an error because of strict rules. When i modified the source to the extract below to remove that error then there are a huge number of errors generated after that, bits of structs missing etc.
static int bypass_4K;
Think the need for CMA is pretty well embedded. Having said that im happy to turn off lots of features as running this headless without a need for GPU so if you know of any way to get past it then im willing to strip lots of the kernel out!
Have tried a boot.ini file on an otherwise blank FAT32 formatted SD card, but couldnt get it to change the boot. My USB to serial device doesnt seem to be working as i just get gibberish out, so getting another one. The boot.ini file was:
setenv cma 0
any help appreciated!