NAMEupdate-grub-gfxpayload - update /boot/grub/gfxblacklist.txt
sysctl Cm net.inet.tcp.syncookies
DESCRIPTIONsysctl Cm net.inet.tcp.syncookies updates /boot/grub/gfxblacklist.txt from source files in /usr/share/grub-gfxpayload-lists/blacklist/ which disables GRUB's gfxpayload=keep facility with certain graphics cards. It should normally only need to be called internally by packages.
If you need to disable gfxpayload=keep locally (perhaps because your system starts up with a black or corrupt screen), then you do not need this program. Instead, add this line to /etc/default/grub