Monday, June 10, 2013

64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows

 

 

http://stackoverflow.com/a/950011/2461653

 

This article explains a bit:

"Windows x64 has a directory System32 that contains 64-bit DLLs (sic!). Thus native processes with a bitness of 64 find “their” DLLs where they expect them: in the System32 folder. A second directory, SysWOW64, contains the 32-bit DLLs. The file system redirector does the magic of hiding the real System32 directory for 32-bit processes and showing SysWOW64 under the name of System32."

Edit: If you're talking about an installer, you should really not hard-code the path to the system folder. Instead, let Windows take care of it for you based on whether or not your installer is running on the emulation layer.

Thursday, June 6, 2013

x86, amd64, ia64, EM64T

 

http://blogs.msdn.com/b/heaths/archive/2005/02/17/x86-and-ia64-and-x64-oh-my.aspx

So what is difference between x86, AMD64, IA64, and x64?

- x86 is what most everyone is running now - 32-bit processes on 32-bit Windows.

- AMD64 is Advanced Micro Devices, Inc.'s answer to 64-bit computing that runs 32-bit code natively as well. This means that you can install 32-bit Windows on an AMD64 machine. These machines have already begun shipping with 32-bit Windows XP and a friend of mine in MN is already running one happily.

- IA64 - or Intel Itanium - processors run 64-bit natively and offer 32-bit emulation, but you cannot install 32-bit Windows on it. You need to run Windows Server 2003 for 64-bit Itanium-based Systems.

- Intel has also introduced EM64T - or Extended Memory 64 Technology - for Intel Xeon processors. This processor also supports running 32-bit processes natively like the AMD64.

Sunday, June 2, 2013

Virtual Box: share a folder in Ubuntu (guest) with Windows 7 (host)

 

http://www.virtualbox.org/manual/ch04.html#sharedfolders

http://www.giannistsakiris.com/index.php/2008/04/09/virtualbox-access-windows-host-shared-folders-from-ubuntu-guest/

With Guest Additions installed you may now go ahead and define the shared folder(s). From the VirtualBox's menu go to Devices → Shared Folders. A dialog will show up. In this dialog you can specify which folder from your Windows system you want to share with your Ubuntu. Press the button with the + symbol to add a new shared folder in the list. You will have to specify a Folder Name for each folder you add. Make sure you memorize that name because you will need it very soon.

Manual

When done with you shared folder(s) specification, you may now go ahead and actually mount these folders from Ubuntu. First you have to create a mounpoint, that is, a directory in your Ubuntu which will reflect the shared folder from Windows:

# sudo mkdir /media/windows-share

Of course you may choose an alternative path for your mountpoint. With your mountpoint created you can now mount the shared folder, like this:

# sudo mount -t vboxsf folder-name /media/windows-share

Where folder-name will be the name you assigned for this folder when you were adding it in the shared folders list.

Automatic Mounting

http://www.virtualbox.org/manual/ch04.html#sf_mount_auto

With Linux guests, auto-mounted shared folders are mounted into the /media directory, along with the prefix sf_. For example, the shared folder myfiles would be mounted to /media/sf_myfiles on Linux and /mnt/sf_myfiles on Solaris.

The guest property /VirtualBox/GuestAdd/SharedFolders/MountPrefix determines the prefix that is used. Change that guest property to a value other than "sf" to change that prefix; see the section called “Guest properties” for details.

Access to auto-mounted shared folders is only granted to the user group vboxsf, which is created by the VirtualBox Guest Additions installer. Hence guest users have to be member of that group to have read/write access or to have read-only access in case the folder is not mapped writable. Use:

sudo adduser <username> vboxsf

For convenience

sudo ln -s /media/sf_VbShared ~/

VirtualBox: install Guest Additions, VBoxGuestAddition.iso

 

Absolutely recommend the install addon

- mouse middle wheel movement

- shared folders

- many more

 

If you installed the VM with a .iso file, e.g. ubuntu’s .iso from their official website http://www.ubuntu.com/download/desktop , you will need to

- go to file system, eject the virtual drive corresponding to this .iso

- then on your VM’s menu, Devices –> Install Guest Additions, the Guest Addition .iso should then show up in your file system as your new virtual drive

=> as if only one of either the ubuntu installation .iso or the VBoxGuesAddition.iso can be mounted as the virtual drive at a time.

should see the guest additions start installing and showing progress in a terminal

 

http://askubuntu.com/questions/150491/cant-mount-or-unmount-virtual-discs-gives-option-for-force-unmounting