[Fedora-livecd-list] livecd-iso-to-disk : cannot create Legacy BIOS bootable partition with gptmbr.bin from syslinux

[Gregory Fowler]

Hi

I think that the disk utility "parted"  is broken with regard to making 
hard drive partitions bootable.  At least when syslinux gptmbr.bin file 
is used to format it.  This is causing the livecd-iso-to-disk utility to 
incorrectly create a USB stick that is capable of UEFI boot but not 
Legacy BIOS boot.
Question:
*Can we get parted to write the bootable flag on the gptmbr.bin 
partition in the same way that sgdisk accomplishes this?
*Or can we use the better tool in this situation (sgdisk) and patch the 
livecd-iso-to-disk script to enable the use of sgdisk  when making USB 
sticks with the gptmbr.bin file from syslinux?


For this test you need ...
UEFI 2.1 compliant system
Legacy BIOS bootable system
Livecd ISO image the was correctly mastered as a UEFI and Legacy 
Bootable system.
livecd-tools-16.3
parted
gdisk
syslinux (with gptmbr.bin)

Run bash -x /usr/bin/livecd-iso-to-disk --reset-mbr --format --efi 
image.iso /dev/sdb  and save the output.
###SAMPLE Output shows sgdisk does not see partition as bootable after 
parted does its work.
###  Then after sgdisk does its work, it shows the partition as bootable.
...
...
Press Enter to continue or ctrl-c to abort
+ read

+ umount /dev/sdb /dev/sdb1
+ :
+ /sbin/parted --script /dev/sdb mklabel gpt
++ LC_ALL=C
++ /sbin/parted --script -m /dev/sdb 'unit b print'
++ grep '^/dev/sdb:'
+ partinfo='/dev/sdb:8019509248B:scsi:512:512:gpt:hp v165w;'
++ echo /dev/sdb:8019509248B:scsi:512:512:gpt:hp 'v165w;'
++ cut -d : -f 2
++ sed -e 's/B$//'
+ size=8019509248
+ /sbin/parted --script /dev/sdb unit b mkpart '"EFI System Partition"' 
fat32 1048576 8018460672 set 1 boot on
+ '[' -x /usr/sbin/sgdisk ']'
+ SGDISK=
++ /usr/sbin/sgdisk /dev/sdb --attributes=1:show
+ SGDISK=
+ echo 'SGDISK reports /dev/sdb attributes: '
SGDISK reports /dev/sdb attributes:
+ echo
+ egrep -i 'bios boot'
+ echo 'parted failed to make the partition Legacy BIOS bootable; USING 
SGDISK '
parted failed to make the partition Legacy BIOS bootable; USING SGDISK
+ /usr/sbin/sgdisk /dev/sdb --attributes=1:set:2
The operation has completed successfully.
++ /usr/sbin/sgdisk /dev/sdb --attributes=1:show
+ SGDISK='1:2:1 (legacy BIOS bootable)'
+ echo 'SGDISK reports /dev/sdb attributes: 1:2:1 (legacy BIOS bootable)'
SGDISK reports /dev/sdb attributes: 1:2:1 (legacy BIOS bootable)
...
...
+ echo 'Target device is now set up with a Live image!'
Target device is now set up with a Live image!
+ exitclean
+ RETVAL=0
+ '[' -d /media/srctmp.NpEBDs ']'
+ '[' -d /media/tgttmp.ui8qin ']'
+ exit 0



Notice that parted is supposed to create a "bootable Flag" for the 
partition on the gptmbr.bin formatted USB stick.
If we reboot from the stick in legacy mode, we get the syslinux error 
"Missing Operating System"
see
http://syslinux.zytor.com/wiki/index.php/Common_Problems#Missing_Operating_System_.28mbr.bin.29 

http://syslinux.zytor.com/wiki/index.php/Common_Problems#Missing_OS_.28gptmbr.bin.29 


If we patch the script like below and use it to re-create the USB stick 
( make it use the gdisk package's "sgdisk" util to make the partition 
bootable), then we can reboot from the USB stick in Legacy Mode and we 
have a proper Legacy/UEFI bootable USB stick that was formatted with 
syslinux gptmbr.bin.


##Patch to prove this out
--- livecd-iso-to-disk    2011-04-28 09:52:40.000000000 -0400
+++ livecd-iso-to-disk_oracle    2011-04-28 09:52:41.000000000 -0400
@@ -422,6 +422,20 @@
      partinfo=$(LC_ALL=C /sbin/parted --script -m $device "unit b 
print" |grep ^$device:)
      size=$(echo $partinfo |cut -d : -f 2 |sed -e 's/B$//')
      /sbin/parted --script $device unit b mkpart '"EFI System 
Partition"' fat32 1048576 $(($size - 1048576)) set 1 boot on
+    #parted may not properly set the gptmbr partition as bootable.
+    #Use sgdisk to check and fix
+    if [ -x /usr/sbin/sgdisk ] ;  then
+    SGDISK=""
+    SGDISK=$(/usr/sbin/sgdisk  $device --attributes=1:show)
+    echo "SGDISK reports $device attributes: $SGDISK"
+    if ! echo $SGDISK | egrep -i 'bios boot' ; then
+      echo "parted failed to make the partition Legacy BIOS bootable; 
USING SGDISK "
+      /usr/sbin/sgdisk $device --attributes=1:set:2
+      SGDISK=$(/usr/sbin/sgdisk  $device --attributes=1:show)
+      echo "SGDISK reports $device attributes: $SGDISK"
+    fi
+    fi
+
      # Sometimes automount can be _really_ annoying.
      echo "Waiting for devices to settle..."
      /sbin/udevadm settle

Thanks
Gregory Fowler
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