Re: [gentoo-user] Dual booting with Windows 10

[Peter Humphrey <peter@prh.myzen.co.uk>]

On Monday, 24 May 2021 16:14:43 BST Michael wrote:

> You can contact me off list if you want to work through the detail of
> configuring your system with and without a boot manager.  I think once it
> clicks, you'll be able to apply your preferred solution without much trouble
> in the future.

Thanks for the offer, Michael, but let me clear a few things up first.

1.  I don't use symlinks in /boot.
2.  I don't use grub, nor any other boot manager.
3.  ...unless you count bootctl, from sys-boot/systemd-boot.
4.  I have the existing ESP mounted on /boot. It belongs to Windows and cannot
be enlarged beyond 100MB.
5.  I have a small second system on the Gentoo disk called Rescue, so I have a
multiple-boot system.

# tree -L 3 /boot
/boot
├── EFI
│   ├── Boot
│   │   └── bootx64.efi
│   ├── Linux
│   ├── Microsoft
│   │   ├── Boot
│   │   └── Recovery
│   └── systemd
│       └── systemd-bootx64.efi
├── System.map-5.10.27-gentoo
├── System.map-5.10.27-gentoo-rescue
├── amd-uc.img
├── config-5.10.27-gentoo
├── config-5.10.27-gentoo-rescue
├── loader
│   ├── entries
│   │   ├── 08-gentoo-rescue-5.10.27.conf
│   │   ├── 09-gentoo-rescue-5.10.27.nonet.conf
│   │   ├── 30-gentoo-5.10.27.conf
│   │   ├── 32-gentoo-5.10.27.nox.conf
│   │   └── 34-gentoo-5.10.27.nonet.conf
│   ├── loader.conf
│   └── random-seed
├── vmlinuz-5.10.27-gentoo
└── vmlinuz-5.10.27-gentoo-rescue

# parted -l
[...]
Model: Samsung SSD 970 EVO Plus 250GB (nvme)
Disk /dev/nvme0n1: 250GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End    Size    File system  Name                          Flags
 1      1049kB  106MB  105MB   fat32        EFI system partition          boot, esp
 2      106MB   123MB  16.8MB               Microsoft reserved partition  msftres
 3      123MB   249GB  249GB   ntfs         Basic data partition          msftdata
 4      249GB   250GB  580MB   ntfs         Basic data partition          hidden, diag

Model: Samsung SSD 970 EVO Plus 250GB (nvme)
Disk /dev/nvme1n1: 250GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system     Name      Flags
 1      1049kB  269MB   268MB   ext4            boot
 2      269MB   34.6GB  34.4GB  linux-swap(v1)  swap-1    swap
 3      34.6GB  51.8GB  17.2GB  ext4            rescue
 4      51.8GB  86.2GB  34.4GB  ext4            root
 5      86.2GB  90.5GB  4295MB  ext4            local
 6      90.5GB  103GB   12.9GB  ext4            home
 7      103GB   129GB   25.8GB  ext4            common
[...]

I followed the installation handbook, boot-loader section, to create a UEFI
boot entry. I followed the syntax precisely, with several variations at
various attempts. In every case, the UEFI BIOS listed the new entry but
couldn't execute it.

I want to be shown a list of systems to boot immediately after the POST, which
I'm sure efibootmgr can't do, so I ran 'bootctl install' to install the code (where?) to give me the ability. That works, though I do remove the directory
with the 32-hex-digit name, and install my own loader.conf.

The system seems to be stable now.

-- 
Regards,
Peter.