China DOS Union

Now report the test results:
287 + 1, display FF;
288 + 1, crash.

debug didn't crash, and the screenshot still shows the original post from Wuyou.

By the way, if you don't explain today, I would have tried blindly last night. That would be torturing people! Fortunately, I didn't try!

I later discovered that you also have the subsequent debug program, and now attach the screenshot. In the same position.

Note that usb2~usb4 are the subsequent programs, correct!

[ Last edited by neiljoy on 2006-7-25 at 12:25 ]

I have again carefully conducted experiments using a virtual machine. The 2.88M is the same as the 1.44M, and it was also successfully done! Hope to finally crack the USB flash drive without clicking!

Okay, you did a good job. I'll study the solution as soon as possible. Wait and see the updates on http://grub4dos.jot.com/.

An update has been uploaded. Do you see if it solves the problem?

[ Last edited by 不点 on 2006-7-25 at 15:28 ]

The one I downloaded is grub_for_dos-2006-07-25.zip. After testing on a USB flash drive, the result is still the same as before. That is:
1. Using grub.exe --config-file=(fd0)/menu.lst, it freezes.
2. Using a batch file to boot the img file in the USB flash drive, it freezes.
The screen display when freezing is the same as before.

Okay, I'll upload another one today.

But can you report the output result of geometry (fd0)?

Also,

cat --hex (fd0)+1
cat --hex (fd0)287+1
cat --hex (fd0)288+1
cat --hex (fd0)2879+1
cat --hex (fd0)2880+1

Will it crash?

[ Last edited by 不点 on 2006-7-25 at 17:21 ]

geometry output:
drive 0x0:c/h/s=80/2/18,The number of sectors=2880,CHS Bytes per Sector=512
partition num:0,Filesystem type unknown,partition type 0x74
partition num:1,Filesystem type unknown,partition type 0x65
partition num:2,Filesystem type unknown,partition type 0x53
partition num:3,Filesystem type unknown,partition type 0xbb
partition num:0,Filesystem type unknown,using whole disk


cat --hex (fd0)+1 has content
cat --hex (fd0)287+1 displays ff
cat --hex (fd0)288+1 crashes
cat --hex (fd0)2879+1 crashes
cat --hex (fd0)2880+1 not crashed, displays error 26.

[ Last edited by neiljoy on 2006-7-25 at 17:55 ]

Uploaded already, try again. Estimated that it should be solved差不多.

In case it still fails, then report the output result of geometry (fd0), and whether the following are deadlocked:

cat --hex (fd0)+1
cat --hex (fd0)287+1
cat --hex (fd0)288+1

[ Last edited by 不点 on 2006-7-25 at 18:56 ]

I just finished downloading, and couldn't wait to test it. The result is -- Mission accomplished!!!!!!!!!
Specially extend the warmest congratulations and the most heartfelt thanks to the creator of grub_for_dos -- Master Budian!

Where there is a will, there is a way!!

I just quickly and roughly tested it once, and then quickly sent out this good news.
Next I will test it more carefully.

Congratulations, neiljoy! The China DOS Union will witness and record your achievements!

This bug has existed for many years (someone reported this bug in the same forum a few years ago but it wasn't resolved). It was your persistent efforts that finally helped solve the problem. As a programmer, I just did my duty. Without your testing, this bug could be said to be very difficult to solve (to the extent of "almost impossible to solve"). You are the protagonist of this action. Congratulations! Also, I say to you that where there is a will, there is a way!

This bug is a bug jointly "owned" by BIOS and GNU GRUB. From the test results you provided, I learned a lot of in-depth information about BIOS (related to int13/ah=41h). These useful information can also be used in debugging other programs. Therefore, I personally express special thanks to you here!

Let's cheer! Let's celebrate!
This seemingly insurmountable difficulty has finally been overcome by Budian!!

After another round of testing, no problems have been found so far.
geometry output:
drive 0x0:c/h/s=96/255/63,The number of sectors=1542240,CHS Bytes per Sector=512
Filesystem type unknown,partition type 0x74
Filesystem type unknown,partition type 0x65
Filesystem type unknown,partition type 0x53
Filesystem type unknown,partition type 0xbb
Filesystem type unknown,using whole disk

Several sectors that crashed on floor 52 are normal, and all have data displayed.

Neiljoy's perseverance is commendable.
Bu Dian Da Shuai's patient guidance is effective.
Congratulations! Congratulations!

"This BUG is a BUG jointly "owned" by BIOS and GNU GRUB. Can you tell me what kind of bug this is?"

The relevant information about this bug has been discussed in detail in another thread written by neiljoy. You can find it by searching for neiljoy on this site:

http://www.cn-dos.net/forum/viewthread.php?tid=22105&fpage=2