(OK) 移动硬盘（或 U盘），安装 CentOS-8.iso Fedora-30-1.2.iso，修改内核参数：pci=nomsi,noaer

# ls /opt/iso
CentOS-8-x86_64-1905-dvd1.iso Fedora-Workstation-Live-x86_64-30-1.2.iso

# fdisk /dev/sdb
设备       启动      起点      末尾      扇区   大小 Id 类型
/dev/sdb1 *         2048 54530047 54528000    26G 83 Linux           # CentOS-8-x86_64-1905-dvd1.iso
/dev/sdb2        61442048 266242047 204800000 97.7G 83 Linux
/dev/sdb3       266242048 625141759 358899712 171.1G 7 HPFS/NTFS/exFAT
/dev/sdb4        54530048 61442047   6912000   3.3G 83 Linux           # Fedora-Workstation-Live-x86_64-30-1.2.iso

# (1) 安装 CentOS-8-x86_64-1905-dvd1.iso

livecd-iso-to-disk --reset-mbr CentOS-8-x86_64-1905-dvd1.iso /dev/sdb1
cp CentOS-8-x86_64-1905-dvd1.iso /run/media/root/centos # /run/media/root/centos is /dev/sdb1

# 移动硬盘启动 CentOS-8，安装源选择 CentOS-8-x86_64-1905-dvd1.iso

# (2) 安装 Fedora-Workstation-Live-x86_64-30-1.2.iso

# fdisk /dev/sdb
设备       启动      起点      末尾      扇区   大小 Id 类型
/dev/sdb1 *         2048 54530047 54528000    26G 83 Linux           # CentOS-8-x86_64-1905-dvd1.iso
/dev/sdb4 *     54530048 61442047   6912000   3.3G 83 Linux           # Fedora-Workstation-Live-x86_64-30-1.2.iso

livecd-iso-to-disk Fedora-Workstation-Live-x86_64-30-1.2.iso /dev/sdb4

# fdisk /dev/sdb
设备       启动      起点      末尾      扇区   大小 Id 类型
/dev/sdb1 *         2048 54530047 54528000    26G 83 Linux           # CentOS-8-x86_64-1905-dvd1.iso
/dev/sdb4        54530048 61442047   6912000   3.3G 83 Linux           # Fedora-Workstation-Live-x86_64-30-1.2.iso

# (3) 修改文件 /run/media/root/centos/syslinux/extlinux.conf，内容如下：

label linux
menu label ^Install CentOS Linux 8.0.1905 (pci=nomsi)
kernel vmlinuz
append initrd=initrd.img inst.stage2=hd:UUID=359a70d1-4ea4-7e42-bc49-50b02f0c58b3 quiet pci=nomsi
label linux
menu label ^Start Fedora-Workstation-Live 30 (pci=nomsi)
kernel vmlinuz
append initrd=initrd.img root=live:UUID=dce64d41-a28d-7f4d-aca1-1729314bcdb6 rd.live.image rw quiet pci=nomsi

label linux
menu label ^Install CentOS Linux 8.0.1905 (pci=noaer)
kernel vmlinuz
append initrd=initrd.img inst.stage2=hd:UUID=359a70d1-4ea4-7e42-bc49-50b02f0c58b3 quiet pci=noaer
label linux
menu label ^Start Fedora-Workstation-Live 30 (pci=noaer)
kernel vmlinuz
append initrd=initrd.img root=live:UUID=dce64d41-a28d-7f4d-aca1-1729314bcdb6 rd.live.image rw quiet pci=noaer

label linux
menu label ^Install CentOS Linux 8.0.1905 (pci=nomsi,noaer)
kernel vmlinuz
append initrd=initrd.img inst.stage2=hd:UUID=359a70d1-4ea4-7e42-bc49-50b02f0c58b3 quiet pci=nomsi,noaer
label linux
menu label ^Start Fedora-Workstation-Live 30 (pci=nomsi,noaer)
kernel vmlinuz
append initrd=initrd.img root=live:UUID=dce64d41-a28d-7f4d-aca1-1729314bcdb6 rd.live.image rw quiet pci=nomsi,noaer

# (4) 安装 CentOS-8-x86_64-1905-dvd1.iso