Bootdisk creation using camera - General Discussion and Assistance - CHDK Forum

Bootdisk creation using camera

  • 5 Replies
  • 3411 Views
Bootdisk creation using camera
« on: 18 / September / 2010, 05:56:36 »
Advertisements
Hello.
I have found the possibility to create bootdisk using camera.
I have mentioned about this early in some topics, but want to describe more detailed here.
To create bootdisk you need to create file boot.req in the root directory of your card and write string "for DC_bootdisk" into it.
Then just format your card using camera and it will be marked as bootable.
This is equivalent to writing string "BOOTDISK" into bootsector at offset 0x40.

And I want to ask someone to test following things:
1. will this work on your camera or not
2. what camera will do if card is bigger than 4Gb

I can't test, but it looks like string "BOOTDISK" will be written, but card will be formated in FAT32 so it will not be bootable in any case.
But maybe I am wrong.

And it looks like Canon scripting have functions MakeBootDisk and MakeScriptDisk for preparing card from script, while MakeScriptDisk looks a little strange because to execute script card should be already prepared.

*

Offline reyalp

  • ******
  • 13751
Re: Bootdisk creation using camera
« Reply #1 on: 18 / September / 2010, 16:44:28 »
Hello.
I have found the possibility to create bootdisk using camera.
I have mentioned about this early in some topics, but want to describe more detailed here.
To create bootdisk you need to create file boot.req in the root directory of your card and write string "for DC_bootdisk" into it.
Then just format your card using camera and it will be marked as bootable.
This is equivalent to writing string "BOOTDISK" into bootsector at offset 0x40.
Have you tested this ? I believe that you have to actually call the eventproc "MakeBootDisk" or "MakeScriptDisk" with those files in place. Simply having the files in place does not cause the camera to make the disk bootable/scriptable.

Don't forget what the H stands for.

Re: Bootdisk creation using camera
« Reply #2 on: 19 / September / 2010, 07:41:11 »
To make disk bootable you need to create boot.req with string "for DC_bootdisk" and then format card using camera.
Maybe lowlevel format is required.
This will kill boot.req during formatting as expected, but will mark card as bootable in the bootsector.

There is no such ability for script disk - it need to be created manually.

*

Offline waldo

  • ***
  • 238
Re: Bootdisk creation using camera
« Reply #3 on: 19 / September / 2010, 12:20:47 »
I just tried this on a S95 with a 4GB card.  I could not get it to work.  I started with a FAT32 card and with a FAT16 card, with and without low level formatting.  Each time the camera formats it to FAT32 and autobooting does not work.


Re: Bootdisk creation using camera
« Reply #4 on: 19 / September / 2010, 15:08:33 »
Sorry, tested once more.
My card was previously prepared.
Don't know why, but formatter does not mark disk as bootable.
Maybe there are some more conditions.

Script functions MakeBootDisk and MakeScriptDisk works fine and does not require *.req files to be present on disk.
« Last Edit: 19 / September / 2010, 15:11:52 by cppasm »

*

Offline reyalp

  • ******
  • 13751
Re: Bootdisk creation using camera
« Reply #5 on: 19 / September / 2010, 16:04:02 »
Script functions MakeBootDisk and MakeScriptDisk works fine and does not require *.req files to be present on disk.
You are right, the .req are not required to call the function. However, the script.req must be in place for the script to actually be run.

The boot.req looks like it should have something to do with formatting, but maybe we are missing some piece.

It has already been verified many times that writing the normal BOOTDISK string does not make FAT32 bootable.

Don't forget what the H stands for.

 

Related Topics