Hi, there is still incorrect information about installation documentation, IMHO.
below is my installation procedure, so it customed, it works for me.
/dev/sda1 for the boot/root/home partition
01. sudo mkfs.ext4 /dev/sda1
02. sudo mount /dev/sda1 /mnt
03. sudo mkdir /mnt/{boot,home}
04. sudo -s
05. yySy arch-install-scripts
06. time cp -ax / /mnt
07. cp -vaT /run/archiso/bootmnt/arch/boot/$(uname -m)/vmlinuz /mnt/boot/vmlinuz-linux
08. genfstab -U -p /mnt >> /mnt/etc/fstab
09. arch-chroot /mnt /usr/bin/zsh
10. change the configuration of pam in /etc/pam.d/su
# %PAM-1.0
# comment below line
# auth sufficient pam_rootok.so
# Uncomment the following line to implicitly trust users in the "wheel" group.
# uncomment below line
auth sufficient pam_wheel.so trust use_uid
# Uncomment the following line to require a user to be in the "wheel" group.
# auth required pam_wheel.so use_uid
auth required pam_unix.so
account required pam_unix.so
session required pam_unix.so
11. Remove some files
12. rm /etc/mkinitcpio-archiso.conf
13. rm -rf /etc/initcpio
14. rm -rf /root/.zlogin /home/<user_account>/.zlogin # or chsh to /bin/bash
15. Remake the img
mkinitcpio -p linux
16. Install the boot loader
syslinux-install_update -iam
17. blkid
obarun / # blkid
/dev/loop0: TYPE="squashfs"
/dev/sda1: UUID="XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX" TYPE="ext4" PARTUUID="XXXXXXXX-XX"
18. edit the file /boot/syslinux/syslinux.cfg and substitue XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX with the UUID of your root partition:
LABEL arch
MENU LABEL Arch Linux
LINUX ../vmlinuz-linux
APPEND root=UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX rw
INITRD ../initramfs-linux.img
LABEL archfallback
MENU LABEL Arch Linux Fallback
LINUX ../vmlinuz-linux
APPEND root=UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX rw
INITRD ../initramfs-linux-fallback.img
19. edit the file /etc/fstab and substitue XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX with the UUID of your root partition:
#
# /etc/fstab: static file system information
#
# <file system> <dir> <type> <options> <dump> <pass>
# /dev/sda1
UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX / ext4 rw,relatime,data=ordere
d 0 1
20. Change the password for root and user if you want
passwd root
passwd obarun
Exit of arch-chroot system
exit
Finally reboot