First, I'll explain my situation
- Device: ASUS x205ta with 32GB eMMC (Windows 8.1+Bing installed). Lets call this
/dev/mmcblk0 - usb flash drive: 64GB Sandisk ultra. installed Ubuntu 14.04. Lets call this
/dev/sda
check out result of parted -l
root@chkwag-X205TA:/home/chkwag# parted -l
Model: SanDisk SanDisk Ultra (scsi)
Disk /dev/sda: 31.6GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 2048MB 2047MB linux-swap(v1)
2 2048MB 2147MB 99.6MB fat32 boot
3 2147MB 31.6GB 29.5GB ext4
Error: /dev/mmcblk0rpmb: unrecognised disk label
Error: /dev/mmcblk0boot0: unrecognised disk label
Error: /dev/mmcblk0boot1: unrecognised disk label
Model: MMC SDW32G (sd/mmc)
Disk /dev/mmcblk0: 31.3GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 106MB 105MB fat32 EFI system partition boot
2 106MB 240MB 134MB Microsoft reserved partition msftres
3 240MB 20.5GB 20.3GB ntfs Basic data partition msftdata
4 20.5GB 31.3GB 10.7GB ntfs Basic data partition hidden, diag
eMMC and flash drive each has a ESP (format: FAT32). Currently, I'm loading Ubuntu through GRUB2(named bootia32.efi) in the ESP of usb flash drive by adding a UEFI menu entry pointing to this bootia32.efi file.(entry grub-stable below)
check out UEFI menu entries:
root@chkwag-X205TA:/home/chkwag# efibootmgr -v
BootCurrent: 0004
Timeout: 2 seconds
BootOrder: 0005,0007,0006,000C,0000,0001,0002,0003
Boot0000* Windows Boot Manager HD(1,800,32000,321f056d-350b-44ac-ac85-b19a4fac6b77)File(\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...e................
Boot0001* UEFI:CD/DVD Drive BIOS(81,0,00)
Boot0002* UEFI:Removable Device BIOS(82,0,00)
Boot0003* UEFI:Network Device BIOS(83,0,00)
Boot0005* grub_stable HD(2,3d0800,2f800,97a32bdd-cbf7-4583-a071-d205f5134f43)File(\EFI\BOOT\bootia32.efi)
Boot0006* fakeMS HD(1,800,32000,321f056d-350b-44ac-ac85-b19a4fac6b77)File(\EFI\FAKE_MS\BOOT\BOOTMGFW.EFI)
Boot0007* grub1 HD(1,800,32000,321f056d-350b-44ac-ac85-b19a4fac6b77)File(\EFI\GRUB32.EFI)
Boot000C* UEFI: SanDisk SanDisk Ultra PMAP ACPI(a0341d0,0)PCI(14,0)USB(2,0)USB(2,0)HD(2,3d0800,2f800,97a32bdd-cbf7-4583-a071-d205f5134f43)..BO
root@chkwag-X205TA:/home/chkwag#
In sense of building a dual-boot system, this does suffice but I wanted to take this further and get the UEFI firmware to load GRUB2 from ESP of eMMC (Just a personal quest). To do this, I just copied bootia32.efi that I used before in ESP of eMMC, and made a UEFI menu entry loading this file explicitly. (entry named grub1. grub32.efi is just a renamed version of bootia32.efi)
Theoretically, I believe this is correct. However, when I use this UEFI menu entry, I will not work and just execute the original windows boot manager also located in the same ESP.
I did everything I could such as renaming bootia32.efi to something else or replacing the original windows boot manager(bootmgfw.efi) with bootia32.efi with the same name. But all attemps failed.
As I said, if everything is set correctly according to THEORY, then what am I missing? What else is there that can somehow ignore my UEFI menu entry that loads GRUB2 and just decides to load windows boot manager? Or as another possibility, bootia32.efi in eMMC's ESP is somehow magically not working?
boot order should not be an issue here since if my menu entry is correct, then there is no need to move on to the next boot order. Besides, I've confirmed that loading bootia32.efi alone should still get me a command line interfaced GRUB2 if grub.cfg is not found nearby.
