Uefi and porteus 3.0

[brokenman]

I understand you only want to talk about flash devices, but the problem is we simply can't assume that a user will install Porteus only to a flash device. It is a portable distro that we report to be installable on all devices. This includes optical, SSD, SCSI, HDI and flash.

[Ed_P]

we simply can't assume that a user will install Porteus only to a flash device.

Can't Porteus determine a device type? If the device is sdbx or higher it implies it's not the machine's hard drive does it not? Or check it's size and if it's 64 MB or less allow the format option to be skipped? (I'm not aware of any machines build in the past 10 yrs with hard drives that small. Years ago yes but not in this century.)

And to be clear I'm talking about your UEFI install script not the standard Porteus install script.

[brokenman]

Simply put ... a hybrid MBR is not going to happen. For now we will have to stick with just a plain MBR that loads Porteus (on a FAT32 partition ) that is big enough for windows to use as storage. This means it will be bootable in both EFI and BIOS systems and windows 7/vista should have no problem seeing the device. People with 2T+ devices will need to use a GPT to get full benefits. Thanks fanthom. Case closed.

[Ed_P]

Simply put ... a hybrid MBR is not going to happen.

For the record, the approach I use did not create a "hybrid MBR" or a "protected MBR", it uses the MBR that the Porteus Install app creates. It then uses GDISK's option to create the GUID Partition Table (GPT) from the MBR. Nothing in the MBR is changed.

[brokenman]

If you created an MBR together with a GPT then you are looking at a hybrid MBR. That's what hybrid means. Also, I am pretty sure if you run gdisk and create a GPT then it will convert the MBR into a protective MBR. You can see in gdisk when you first run it that the device has an MBR only. Then after running it you will see a GPT and a 'protective MBR'. As for what the exact difference between the two is, well, I'm not sure.

In any case the method we will use won't use a GPT. As far as I know only windows needs a GPT to boot from. Most linux-like systems will happily boot from a standard FAT32 partition without a GPT. I'm putting together an installer that I will pass on for testing. More challenging than I anticipated.

[donald]

--> protective mbr <--
This MBR defines exactly one partition that takes up the entire disk as unknown partition type.
This prevents that old operating systems and partitioning/mbr tools which do not support GPT,
can cause damage.
Therefore it is called "protective".. 8)

[brokenman]

Confirmed.

"The protective MBR is an MBR that defines a single partition entry (of type 0xEE) that covers the entire area of the disk used by GPT structures and partitions. It is designed to prevent GPT-unaware programs from accidentally modifying a GPT disk."

(Apple TN2166)

[Ed_P]

The MBR partition on my Porteus UEFI flash drive is not type 0xEE.

Code: Select all

D:\Users\Ed\My Utilities\MBRfix>mbrfix /drive 1 driveinfo
Drive 1
Cylinders = 948
Tracks (heads) per cylinder = 255
Sectors per track = 63
Bytes per sector = 512
Disk size = 7797565440 (Bytes) = 7 (GB)

D:\Users\Ed\My Utilities\MBRfix>mbrfix /drive 1 listpartitions
# Boot Size (MB) Type
1 Yes      7440   11  WIN95 OSR2 32-bit FAT
2             0    0  None
3             0    0  None
4             0    0  None

It is not Protected, not changed by Gdisk, when it read it in creating the GPT table, and thus not a hybrid. It is just a plain old simple MBR record, created by the Porteus install utility, that works allowing older OS systems to read my UEFI Porteus booting flash drive, like now on my Windows 7 machine.

And while I haven't tried it yet I suspect USB capable TVs will be able to read it also.

[Ed_P]

A new way to convert MBR to GPT!! And no data lost.

https://docs.microsoft.com/en-us/window ... mbr-to-gpt

[fulalas]

The big question is: does it allow us to boot through UEFI using a NTFS partition?

[Ed_P]

Well, the small EFI partition has to be FAT32 ttbomk but not the other partitions where the OSs are installed.

On my Dell I have 8 partitions, the 1 EFI partition and 7 NTFS partitions. The partition table is GPT according to GParted.

[fulalas]

And here we go with chaos, hahaha! I just want things to be simple The funny thing is that there's nothing on the UEFI specification requiring a FAT32 partition to work, however, for an unknown reason motherboard manufacturers decided that non-FAT32 partitions are not good for UEFI.

[francois]

Are we going to have a real tutorial on uefi installation for porteus 4.0?

[Ed_P]

I suspect it's pretty much the same as posted here: UEFI Boot Confusion [Solved]

All that should be needed is the following:

• Create your Porteus file online at: build.porteus.org
  Be sure to select 64bit and the UEFI enabled.
  Create one single FAT32 partition on the USB
  Put all the files from the ISO onto the USB stick
  Open a root terminal and change into the boot folder on the USB stick
  Run the Porteus-installer-for-Linux.com

From a standard porteus install (and assuming your USB partition is at sdb1)

Code: Select all

mloop /path/to/my/porteus.iso
cp -a /mnt/loop/* /mnt/sdb1
sync
cd /mnt/sdb1/boot
./Porteus-installer-for-Linux.com

That's all.

As for formating the drive:

Code: Select all

## Run GParted to partition & format the USB drive with a msdos Partition table.  ##
##  Use GParted's View > Device Information to check Partition Table type.        ##
##  Use GParted's Device > Create Partition Table if Partition Table shows as GPT.##
## Or under Windows use:                                                          ##
## > diskpart          * Run Command Prompt with Admin Rights.                    ##
## > list disk                                                                    ##
## >....                                                                          ##
## > select disk 1     * Note: disk nbr is the nbr of the USB disk                ##
## > clean                                                                        ##
## > create partition primary                                                     ##
## > exit

[fulalas]

I might be wrong, but 'Porteus-installer-for-Linux.com' usually formats on for legacy mode not UEFI. Or at least that's what I saw yesterday after countless tries of booting Porteus through UEFI -- no success at all.