Re: Install Debian 10 amd64 onto USB flash drive with and for Macintosh
On Wed 01 Sep 2021 at 16:00:13 (-0700), David Christensen wrote:
[three long posts]
That was very useful. I've condensed it into a file (attached) for
my own use. The footnotes are notes, guesses and queries.
My main question is — there are three identical listings taken at
different times; all say:
> # mount | grep '.dev.sd'
> /dev/sdb3 on / type ext4 (rw,relatime,errors=remount-ro)
> /dev/sdb1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro)
and yet two are labelled as wrong, and the third as correct.
I found the device letters a bit confusing when you're running the
rescue system. AFAICT, sda is always the SSD. So I was perplexed
by "Rescue operations -> Execute shell in /dev/sda3" because
your SSD only appeared to have two partitions in the OP.
What seems to be missing from the account is any consideration of
the so-called NVRAM variables, about which I know nothing. I'm
still working through how hiding the EFI/debian tree makes the
option-less booting suddenly work, but then, I don't know how
closely the Option key corresponds to pressing F12 on, say, a
Dell PC, which is how you set the device boot order.
(I haven't touched a Mac since the last century when they were
in a little AiO box.)
Cheers,
David.
Post 1 (31 Aug 2021 15:31:43 -0700)
Option boot with d-i inserted:
Select an EFI Boot disk (unclear whether SSD vs USB, or USB's bootx64.efi vs grubx64.efi)
Install buster onto newly inserted USB → "buster-mac"
Debian tree for ESP (silently) onto SSD's ESP¹
Boot with USB inserted (twice):
SSD's ESP debian tree points to USB
buster-mac runs
Boot without USB inserted:
SSD's ESP Debian tree points to USB
Grub>
Option boot without USB inserted:
Sees SSD
MacBook firmware starts macOS
Command-R boot:
MacBook firmware stuff
Boot with USB inserted:
SSD's ESP Debian tree points to USB
buster-mac runs again
fdisk shows Mac OS on sdX2, buster-mac on sdX3
SSD's ESP is mounted at /boot/efi
SSD's ESP contains APPLE and debian
Post 2 (31 Aug 2021 17:39:37 -0700)
Option boot with USB inserted:
Still sees only SSD
Boot with USB inserted (perhaps continuing from Option boot):
buster-mac runs
Listing of d-i's ESP with bootx64.efi² and grubx64.efi
USB's ESP is empty
Repeat listing of SSD's ESP
Ruminations on copying files³
Post 3 (1 Sep 2021 16:00:13 -0700)
Boot Rescue with d-i inserted:
Insert USB
Select USB's / as root filesystem
Execute a shell in sda3⁴
Edit /etc/fstab to mount USB's ESP, not SSD's
Mount USB's ESP
Install Grub, choosing USB's ESP
Boot with d-i and USB inserted:
Something⁵ displays a Grub menu
buster-mac selected and runs
Boot with USB inserted:
buster-mac selected and runs
Reports "Mount device for /boot/efi is wrong⁶ -- still using internal SSD, not USB flash drive."
Boot Rescue with d-i inserted:
Insert USB
Select USB's / as root filesystem
Install Grub, forcing "Removable media path"⁷
Boot with d-i and USB inserted:
Something⁵ displays a Grub menu
buster-mac selected and runs
Boot with USB inserted:
buster-mac selected and runs
Reports "Wrong⁶ -- internal SSD ESP is mounted at /boot/efi."
Option boot with USB inserted:
Sees SSD and EFI Boot⁸
EFI Boot selection starts buster-mac
Reports success after the same listing as the two "failures"
Boot with or without USB inserted:
macOS runs, buster-mac never runs
Option boot with USB inserted:
Sees SSD and EFI Boot⁸
EFI Boot selection starts buster-mac
Mount SSD's ESP
Move the SSD's ESP debian tree, leaving the APPLE one
Boot with USB inserted:
buster-mac runs (no Option/selection needed now)
Listing USB's ESP, identical to a standard Debian installation's
Listing of fstab mentions sdd in the comments, rather than sdc⁹
¹ Not the desired result, of course
² I think bootx64.efi might be the secure boot shim?
³ Copying EFI files might not be enough: what about NVRAM variables?
⁴ Does sda3 exist (on the SSD)?
⁵ Presumably USB ESP could do this, and perhaps SSD ESP as well
⁶ Not sure why: buster-mac has sdb3 on / and sdb1 on /boot/efi
Both these are on sdb which is the USB
There are three identical lists from mount | grep '.dev.sd'
⁷ Is this these three files? /boot/efi/EFI/BOOT/*
⁸ How different is this selection screen from the very first one?
⁹ Was sdc the firmware stick during the original installation?
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