Booting into BIOS from bootcamp

Macs do not run BIOS, but use a compatibility layer called CSM-BIOS. There is no user interface. CSM-BIOS builds the boot device list on the fly based on what is currently plugged in.

acperry7 wrote:

In light of that, I made a system repair disc in the form of a usb; however, now I can't get into the BIOS menu in order to change the boot order to boot the usb in the first place.

Boot into OS X .

Plug-in your Windows USB Repair Disk.

Go To System Preferences -> Startup Disk.

Select your Bootcamp Windows (not your USB Repair).

Click on Restart.

Windows should boot from you USB.

Here is an example of W7 Recovery using USB - https://imgur.com/a/1DaOE#0.

You can see the gpt using sudo gpt -vv -r show /dev/disk0. The Fdisk entry you posted is called a protective MBR.

On all Macs (rom about 2006+), all disks are GPT (APM was used before that which transitioned around Leopard/Snow Leopard time frame).

http://www.rodsbooks.com/gdisk/hybrid.html

https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/ man8/gpt.8.html

http://www.mactech.com/articles/mactech/Vol.23/23.03/APMtoGPT/index.html

What year/model is your Mac?

What is the version of Windows?

Was the old partition removed and new one created using Bootcamp Assistant or Disk Utility?

On newer (2013+) Macs, windows can be installed using EFI or MBR. MBR is the legacy (old method) and is equivalent to BIOS on a PC. EFI is the newer method and does not use a MBR. W8+ support EFI.

Resizing a Windows partition is not permitted when using the MBR method. It requires a re-install of Windows from scratch. Restoring a Windows Image backup to a larger partition is problematic on Macs. If you can, I suggest re-installing Windows from scratch. If you Mac is a late 2013 model, I recommend using the EFI method.

acperry7 wrote:

I got it early 2015 which I think means it is a mid 2014 15' Retina Macbook Pro. The Windows is 8.1 Pro. I removed the old partition via Bootcamp Assistant.

It supports UEFI, so a Bootcamp Assistant is really not necessary.

I basically made a USB to install windows 8.1 in the first place, all ran well but decided to re-partition. So I removed the old partition via bootcamp, made a new, bigger partition, then reinstalled windows using the same USB I made the first time around and it installed without a hitch, but now I can't seem to use the system image I made on an external hard drive.

The USB (and the underlying Windows DVD/ISO) supports both methods, EFI and MBR. It depends whether the Alt key was used and Windows (BIOS) or EFI Boot (EFI) was chosen.

If I installed using the same method, does that mean I'm give nan option to install windows using EFI or MBR? I didn't try resizing the bootcamp partition because I was worried that if I did so, I would end up corrupting a partition and be unable to use it so I decided to play it safe. Is there any way to for sure tell that I am using MBR? That would mean I somehow managed to install EFI the first time but MBR the second (?)

You can check by looking at the output of sudo fdisk /dev/disk0. More than one entry indicates MBR (usually 4 entries) are expected.

acperry7 wrote:

Okay so I ran MsInfo32 in "Run" and it said that for my BIOS I am running UEFI and not Legacy. So, now I'm guessing it something to do with the USB bootable that I made or the way that it is running. I made the recovery drive right out Windows which is puzzling why it is not working properly...

Are there any alternative ways to make a recovery drive using a USB?

The error messages during the restore indicate you used EFI initially, which means BCA created the MBR (and the supporting GPT entries), but by choosing the EFI boot, the MBR was ignored. Subsequent install was done using the MBR, and the System Image cannot be crossed across EFI and MBR. A System Image restore on a Mac has other challenges like partition sizes, MBR recreation, etc.

Do you have data on the old System Image you want restored? If yes, use EFI Boot (without using BCA) by creating a GPT partition using Disk Utility of the size you want (I use Free Space), install Windows using EFI boot, then try a image restore. Since the image restore already has BC drivers, you will not need to re-install them (provided the image included the BC drivers to allow proper functioning).

If it is not critical data, I suggest starting from scratch and installing EFI Windows for flexibility. MBR is rigid and resizing requires re-installation.

1. Since the current installation is MBR, use only Bootcamp Assistant, nothing else, and Remove Windows. Check the output of sudo fdisk /dev/disk0 to ensure there is a single entry. Please make a backup of OSX partition.

2. Go to Disk Utility. Create a partition of the size you want and format it as Free Space.

3. Plug-in your USB with Windows/BC Drivers.

4. Power cycle Mac and hold Alt key. Choose EFI boot (not Windows).

5. Choose the newly created Free Space partition (do not touch any other partition).

6. You will be prompted for NTFS formatting. The Free Space will be split into two partitions, MSR (128MB) and MSD. MSD will become the NTFS partition.

7. Once the Windows works, try your System Image Restore.

This is the disk layout from a 2013 rMBP running W8.1 64-bit in EFI mode. The highlighted entries are the MSR and MSD partitions on this Mac.

gpt show: /dev/disk0: mediasize=500277790720; sectorsize=512; blocks=977105060

gpt show: /dev/disk0: PMBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 977105059

start size index contents

0 1 PMBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 487712920 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

488122560 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

489392096 32

489392128 262144 4 GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE

489654272 487450624 5 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

977104896 131

977105027 32 Sec GPT table

977105059 1 Sec GPT header

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 977105059] <Unknown ID>

2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

For an EFI installation, MBR is not used. The entire disk is encapsulated in the first MBR entry inside a Protective MBR. MSR/MSD are EFI constructs, not MBR sub-types. You can see it when you look at size, it has the whole disk.

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 sectors]

...

1: EE 1023 254 63 - 1023 254 63 [ 1 - 977105059] <Unknown ID>