Tiny Core's small enough that I'll often throw the entirety of it in /boot or /boot/EFI on my Linux desktops as a recovery environment.
How can I put an image in /boot and load and run it from GRUB?
Once I'm back home I'll put up a fuller write-up.
You mean the grub configuration file that shouldn't be edited?
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#
It is a pet peeve of mine, but according to the good people that wrote GRUB2, grub.cfg is subject to auto-magic modifications when updating the (main) Linux install, so it shouldn't be edited manually but rather sort of scripted.
For a GRUB2 installed to harddisk, modifications should be written to
40_Custom
https://help.ubuntu.com/community/Grub2/CustomMenus
otherwise (it depends on which Linux distro is the "main" one) it can happen that at next update the grub.cfg is recreated losing your changes to it.
In any case, something to the effect of
root (hd0,1)
kernel /tinycore/vmlinuz tce=sda1/tinycore/tce vga=794
initrd /tinycore/core.gz
And (as a side note) one could make a separate, static .cfg, let's say tiny.cfg and load it from shell with configfile, aka configfile /tiny.cfg.