On Sunday 29 Jan 2017 14:44:45 Tom H wrote: > On Sat, Jan 28, 2017 at 2:31 PM, Mick <michaelkintz...@gmail.com> wrote: > > rEFInd is definitely a slick and useful boot manager for multibooting. > > On this occasion I did not install it, but decided to remain > > minimalist, because I do not want to interfere much with the AppleMac > > installation. > > > > So, I created /boot/EFI/LINUX/ on /dev/sda1, leaving the original > > /boot/EFI/APPLE as was and copied in the LINUX/ directory just the > > gentoo kernel image, .config and System files. I named the kernel > > image 'bootx64-4.4.39-gentoo.efi' to differentiate from other images I > > will install over time. > > > > Then using the efibootmgr I set up bootx64-4.4.39-gentoo.efi as the > > default boot kernel and when the MackBook is started it boots straight > > into Gentoo, in what it feels like milliseconds. :-) > > > > When I need to boot into MacOS I have to press the alt key (aka Option > > ⌥ key) as I power it on and the Apple firmware boot loader takes over. > > What I don't know yet is if a MacOS upgrade will wipe the > > /boot/EFI/LINUX/ in /dev/sda1 as it upgrades the APPLE files, but it > > is easy to boot with a LiveUSB and copy over the Linux kernel once > > more. > > Apple doesn't boot from the ESP [1] so it most likely won't touch > "/boot/EFI/LINUX/". > > For example, on my MacBook, the ESP only has what looks like hardware > updaters.
Yes, this is where firmware updates install images for the hardware and these are flashed/loaded when the MacOS boots. > # diskutil list disk0 > /dev/disk0 (internal): > #: TYPE NAME SIZE > IDENTIFIER 0: GUID_partition_scheme 500.3 GB > disk0 1: EFI EFI 314.6 MB > disk0s1 2: Apple_CoreStorage Macintosh HD 499.3 GB > disk0s2 3: Apple_Boot Recovery HD 650.0 MB > disk0s3 > > > # diskutil mount readOnly -mountpoint ESP disk0s1 > Volume EFI on disk0s1 mounted > > > # ls -R ESP/EFI > APPLE > > ESP/EFI/APPLE: > EXTENSIONS FIRMWARE UPDATERS > > ESP/EFI/APPLE/EXTENSIONS: > Firmware.scap > > ESP/EFI/APPLE/FIRMWARE: > MB91_0154_B09_LOCKED.fd > > ESP/EFI/APPLE/UPDATERS: > MULTIUPDATER USBCH USBCVA > > ESP/EFI/APPLE/UPDATERS/MULTIUPDATER: > HPMUtil.efi Mac-9AE82516C7C6B903.epm MultiUpdater.efi flasher_base.smc > Mac-9AE82516C7C6B903-B0_3.72.bin Mac-9AE82516C7C6B903.smc > SmcFlasher.efi flasher_update.smc > > ESP/EFI/APPLE/UPDATERS/USBCH: > HPMUtil_v39.efi J93-USBC-NVM-2.72.0-P_B0-S.bin > > ESP/EFI/APPLE/UPDATERS/USBCVA: > HPMUtil.efi fw-p1-USBCVideoAdapter-S.bin > # > > > [1] Apple's EFI firmware can read hfsplus and it boots (IIRC since OS > X 10.10) from a kernel on the Apple_Boot partition (disk0s3). Yes, Apple's firmare reads the blessed hfs+ partition and fishes out its bootx64.efi file kernel image, but I thought this was from the second partition where the OS is installed. I'll have a look tomorrow when I boot it up. -- Regards, Mick
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