GRUB4DOS UEFI does not recognize all partitions in GPT HDD/SSD and ISO formats

[nvcdhl1975]

Thank the developers for your effort

I have used GRUB4DOS legacy to boot ISO files that stored in USB flash drive (NTFS file system). It boot successfully into ISO live CD/DVD (Linux and Windows)

But when I use GRUB4DOS UEFI (2023-11-29) with same MENU.LST (has been changed the suitable path for ISO files) to boot ISO files that stored in HDD/SSD drive, it is failed to boot. The HDD/SSD partition types is GPT with NTFS file system. GRUB4DOS UEFI can mount the first NTFS partition only, others NTFS partition can not be recognized. And the ISO files can not be loaded although the ISO files can be loaded by GRUB4DOS legacy.

Please make some changes for GRUB4DOS UEFI (2023-11-29):

1. To mount ALL NTFS partitions on GPT HDD/SDD.
2. To load ISO file correctly as same as GRUB4DOS legacy

[yaya2007]

Boot the system using 'GRUB4DOS legacy'.
Execute 'geometry (hd0)' on the command line.
Execute 'root (hd0,3)' on the command line.
Execute 'root (hd0,5)' on the command line.
Start windows 10 mini on partition (hd0,3) and see if it succeeds.

[nvcdhl1975]

Hi yaya2002
Following your instruction, I have used GRUB4DOS legacy to boot ISO files on my HDD
No luck, same as GRUB4DOS UEFI the GRUB4DOS legacy 0.46a (2023-11-27) did not detect all of partitions in HDD (GPT partition table)
I have checked HDD by GEOMETRY command and the results is same as GRUB4DOS UEFI. In the attached picture, HDD is (hd1) because I use USB drive (hd0) to boot my system to check all partitions table of my HDD
Now I understand that, I can use GRUB4DOS legacy to boot ISO files successfully because the ISO files were stored in the first partition of my USB which can be detect by both GRUB4DOS UEFI the GRUB4DOS legacy, other partitions may not be detected

[yaya2007]

Boot the system using 'GRUB4DOS legacy'.
Execute 'geometry (hd1)' on the command line.
Execute 'root (hd1,3)' on the command line.
Execute 'root (hd1,5)' on the command line.
Start windows 10 mini on partition (hd1,3) and see if it succeeds.

[nvcdhl1975]

Hi yaya2002

I have tried GRUB4DOS UEFI with MENU.LST

color light-green/black light-red/black white/black white/black
timeout 30
default /default

title Windows 10 Mini (64bit)
map --mem (hd0,3)/LIVE1064.ISO (0xff)
map --hook
chainloader (0xff)
boot

title Ubuntu 22 (64bit)
map --mem (hd0,3)/UBT2204.ISO (0xff) || map --heads=0 --sectors-per-track=0 (hd0,3)/UBT2204.ISO (0xff)
map --hook
root (0xff)
kernel /casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity iso-scan/filename=(hd0,3)/UBT2204.ISO quiet splash ---
initrd /casper/initrd

title Reboot System
reboot

title Halt System
halt

It is OK to boot into both WinPE and Live UBUNTU
But when I execute 'root (hd0,5)' on the command line as your instruction, GRUB4DOS UEFI give an error message "CANNOT MOUNT SELECTED PARTITION".
GRUB4DOS UEFI has been installed on my HDD.

With GRUB4DOS legacy installed on my USB drive, I have tried same steps and get same results, only change parameters (hd0) to (hd1) because ISO files were stored on my HDD

[yaya2007]

Execute 'root (hd1,3)' on the command line.
Start windows 10 mini on partition (hd1,5) and see if it succeeds.

Can I intercept the PBR of (hd1,3) and (hd1,5) partitions, that is, the boot sector, and intercept 4 sectors.

[nvcdhl1975]

Hi yaya 2007

Following your instruction, I tried to boot WinPE on partition (hd1,5). No luck

[yaya2007]

I don't have conditional testing here. Please help me test it and provide screenshots for feedback.
Execute on the command line: root (hd0,5).
grldr.rar.txt

[nvcdhl1975]

Hi yaya2007,
Because you attached legacy version (not UEFI version) of GRUB4DOS, so I have tested it on USB drive to boot.
The USB drive is (hd0), the HDD drive is (hd1)
The 1st picture shows the results after executing of the command GEOMETRY
The 2nd picture shows the results after executing of the command ROOT
The 3rd picture shows the results after executing of the command MAP ISO file

[yaya2007]

There is a problem with the BPB table of the (hd1,5) partition table.
The number of sectors per track is 0.Usually 0x3f.
Give it another try.
grldr.rar.txt

[nvcdhl1975]

Hi yaya2007,
After trying your copy of GRUB4DOS, the pictures bellow are the results

• geometry hd(1)
• root hd(1,5)
• map hd(1,5)/BACKUP/INSTALL/LIVE1064.ISO (0xff)

[yaya2007]

correct: (hd1,5)
error: hd(1,5)

[yaya2007]

correct: (hd1,5)
error: hd(1,5)

[yaya2007]

Please test again