At Sun, 31 May 2026 19:03:38 +0200 didier gaumet <[email protected]> wrote:
> > Le 31/05/2026 à17:46, Paul Duncan a écrità: > > Hi, > > > > My 15 year old son has found an old 2011 iMac in the side of the road. > > Long story short is that the processor probably works, but we think the > > GPU is dead as we cannot get video out of the mini display port > > connector, or the screen. > > > > So, I would like to boot from a Debian live ISO with the following > > kernel parameters (set in grub.cfg). > > > > ààconsole=ttyUSB0,19200n8 > > > > Now, I can mount up the ISO in loop mode, and get into grub.cfg, but how > > do I write this back to the ISO so that I can put in on a USB flash drive? > > > > Thanks! > > > > Paul. > > Hello, > > I don't think you need to do that: > https://www.debian.org/releases/stable/amd64/ch05s01.en.html > Chapter 5.1.5. The Boot Screen > "[...]If you wish or need to add any boot parameters for either the > installer or the kernel, press Tab (BIOS boot), or e then down arrow > three times then end, to edit the âÂÂlinuxâ line of the boot entry > (UEFI > boot). This will bring the boot command for the selected menu entry and > allow you to edit it to suit your needs. Note that the keyboard layout > at this point is still QWERTY. The help screens (see below) list some > common possible options. Press Enter (BIOS boot) or F10 (UEFI boot) to > boot the installer with your options; pressing Esc will return you to > the boot menu and undo any changes you made.[...] > Note: this assumes that the keyboard & basic *graphics* screen works. If the graphics screen in tty mode does not work, you can't do this. I don't know if an iMac exposes a tty console port or even if the iMac motherboard even has a PC-style "bridge" chipset. (*PC* motherboarda have a bridge chip which contains basic I/O interfaces (IDE/SATA, serial, USB, floppy, etc.) following standard PC interface logic. I am not sure what Apple's x86 systems do exactly. It might be the same, but I am not sure. But yes, it is not really possible to edit and re-write the ISO. The ISO-9660 file system is read-only by design. If you change the GRUB configuration you need to re-create the ISO-9660 from scratch -- this is doable, but a non-trivial process. > (you can use an Debian install media but I suppose a Debian live media > would propose the same way of entering parameters) The OP is using a Debian install ISO. > > > > -- Robert Heller -- Cell: 413-658-7953 GV: 978-633-5364 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services [email protected] -- Webhosting Services
