need help on booting installer from hd media

[Long Wind <longwind2@yahoo.com>]

http://ftp.funet.fi/pub/Linux/INSTALL/Debian/dists/Debian10.8/main/installer-i386/current/images/hd-media/initrd.gz

http://ftp.funet.fi/pub/Linux/INSTALL/Debian/dists/Debian10.8/main/installer-i386/current/images/hd-media/vmlinuz

i have buster at sda2 and copy files above to /root

and add installer entry to grub.cfg and run grub-install

menuentry 'New Install' {
insmod part_msdos
insmod ext2
set root='(hd0,msdos2)'
linux /root/vmlinuz
initrd /root/initrd.gz
}

it doesn't work, what's wrong with it?

see https://www.debian.org/releases/stable/i386/ch05s01.en.html#boot-initrd

i think '(hd0,msdos1)' isn't intuitive