hi!
you just create a u-boot.txt file with the kernel parameters
like this:
…
setenv mmcboot "setenv bootargs console=ttyS0,115200 root=${mmcroot} mem=1020M memmap=4M$1020M rw rootwait;bootz ${loadaddr} - ${fdtaddr}"
run mmcload;
run mmcboot;
…
Create the u-boot.scr
~/cv_soc_devkit_ghrd/software/spl_bsp/uboot-socfpga/tools/mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n “My script” -d u-boot.txt u-boot.scr
(refer http://rocketboards.org/foswiki/view/Documentation/GSRD131ProgrammingFPGA#GSRD_FPGA_Configuration)
Copy it to the fat partition.
For more information
http://blackfin.uclinux.org/doku.php?id=reduce_kernel_memory_footprint&s[]=kernel&s[]=memory
And you dont have to rebuild linux!
bye