doc: Refresh URLs in the qemu-tech documentation

The TwoOStwo and Willows page seem to have disappeared completely,
and also some of the other links were not pointing to the right
locations anymore.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 qemu-tech.texi | 73 ++++++++++++++++++++++++----------------------------------
 1 file changed, 30 insertions(+), 43 deletions(-)

On 25/09/2015 11:38, Thomas Huth wrote:
> The TwoOStwo and Willows page seem to have disappeared completely,
> and also some of the other links were not pointing to the right
> locations anymore.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  qemu-tech.texi | 73 ++++++++++++++++++++++++----------------------------------
>  1 file changed, 30 insertions(+), 43 deletions(-)
> 
> diff --git a/qemu-tech.texi b/qemu-tech.texi
> index b6fcb2d..022017d 100644
> --- a/qemu-tech.texi
> +++ b/qemu-tech.texi
> @@ -320,7 +320,7 @@ SH4
>  @node QEMU compared to other emulators
>  @section QEMU compared to other emulators
>  
> -Like bochs [3], QEMU emulates an x86 CPU. But QEMU is much faster than
> +Like bochs [1], QEMU emulates an x86 CPU. But QEMU is much faster than
>  bochs as it uses dynamic compilation. Bochs is closely tied to x86 PC
>  emulation while QEMU can emulate several processors.
>  
> @@ -333,25 +333,25 @@ than QEMU (in particular it does register allocation) but it is closely
>  tied to an x86 host and target and has no support for precise exceptions
>  and system emulation.
>  
> -EM86 [4] is the closest project to user space QEMU (and QEMU still uses
> +EM86 [3] is the closest project to user space QEMU (and QEMU still uses
>  some of its code, in particular the ELF file loader). EM86 was limited
>  to an alpha host and used a proprietary and slow interpreter (the
> -interpreter part of the FX!32 Digital Win32 code translator [5]).
> +interpreter part of the FX!32 Digital Win32 code translator [4]).
>  
> -TWIN [6] is a Windows API emulator like Wine. It is less accurate than
> -Wine but includes a protected mode x86 interpreter to launch x86 Windows
> -executables. Such an approach has greater potential because most of the
> -Windows API is executed natively but it is far more difficult to develop
> -because all the data structures and function parameters exchanged
> +TWIN from Willows Software was a Windows API emulator like Wine. It is less
> +accurate than Wine but includes a protected mode x86 interpreter to launch
> +x86 Windows executables. Such an approach has greater potential because most
> +of the Windows API is executed natively but it is far more difficult to
> +develop because all the data structures and function parameters exchanged
>  between the API and the x86 code must be converted.
>  
> -User mode Linux [7] was the only solution before QEMU to launch a
> +User mode Linux [5] was the only solution before QEMU to launch a
>  Linux kernel as a process while not needing any host kernel
>  patches. However, user mode Linux requires heavy kernel patches while
>  QEMU accepts unpatched Linux kernels. The price to pay is that QEMU is
>  slower.
>  
> -The Plex86 [8] PC virtualizer is done in the same spirit as the now
> +The Plex86 [6] PC virtualizer is done in the same spirit as the now
>  obsolete qemu-fast system emulator. It requires a patched Linux kernel
>  to work (you cannot launch the same kernel on your PC), but the
>  patches are really small. As it is a PC virtualizer (no emulation is
> @@ -359,13 +359,13 @@ done except for some privileged instructions), it has the potential of
>  being faster than QEMU. The downside is that a complicated (and
>  potentially unsafe) host kernel patch is needed.
>  
> -The commercial PC Virtualizers (VMWare [9], VirtualPC [10], TwoOStwo
> -[11]) are faster than QEMU, but they all need specific, proprietary
> +The commercial PC Virtualizers (VMWare [7], VirtualPC [8]) are faster
> +than QEMU (without virtualization), but they all need specific, proprietary
>  and potentially unsafe host drivers. Moreover, they are unable to
>  provide cycle exact simulation as an emulator can.
>  
> -VirtualBox [12], Xen [13] and KVM [14] are based on QEMU. QEMU-SystemC
> -[15] uses QEMU to simulate a system where some hardware devices are
> +VirtualBox [9], Xen [10] and KVM [11] are based on QEMU. QEMU-SystemC
> +[12] uses QEMU to simulate a system where some hardware devices are
>  developed in SystemC.
>  
>  @node Portable dynamic translation
> @@ -608,64 +608,51 @@ way, it can be relocated at load time.
>  @table @asis
>  
>  @item [1]
> -@url{http://citeseer.nj.nec.com/piumarta98optimizing.html}, Optimizing
> -direct threaded code by selective inlining (1998) by Ian Piumarta, Fabio
> -Riccardi.
> +@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,
> +by Kevin Lawton et al.
>  
>  @item [2]
> -@url{http://developer.kde.org/~sewardj/}, Valgrind, an open-source
> -memory debugger for x86-GNU/Linux, by Julian Seward.
> +@url{http://www.valgrind.org/}, Valgrind, an open-source memory debugger
> +for GNU/Linux.
>  
>  @item [3]
> -@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,
> -by Kevin Lawton et al.
> +@url{http://ftp.dreamtime.org/pub/linux/Linux-Alpha/em86/v0.2/docs/em86.html},
> +the EM86 x86 emulator on Alpha-Linux.
>  
>  @item [4]
> -@url{http://www.cs.rose-hulman.edu/~donaldlf/em86/index.html}, the EM86
> -x86 emulator on Alpha-Linux.
> -
> -@item [5]
>  @url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/@/full_papers/chernoff/chernoff.pdf},
>  DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton
>  Chernoff and Ray Hookway.
>  
> -@item [6]
> -@url{http://www.willows.com/}, Windows API library emulation from
> -Willows Software.
> -
> -@item [7]
> +@item [5]
>  @url{http://user-mode-linux.sourceforge.net/},
>  The User-mode Linux Kernel.
>  
> -@item [8]
> +@item [6]
>  @url{http://www.plex86.org/},
>  The new Plex86 project.
>  
> -@item [9]
> +@item [7]
>  @url{http://www.vmware.com/},
>  The VMWare PC virtualizer.
>  
> -@item [10]
> -@url{http://www.microsoft.com/windowsxp/virtualpc/},
> +@item [8]
> +@url{https://www.microsoft.com/download/details.aspx?id=3702},
>  The VirtualPC PC virtualizer.
>  
> -@item [11]
> -@url{http://www.twoostwo.org/},
> -The TwoOStwo PC virtualizer.
> -
> -@item [12]
> +@item [9]
>  @url{http://virtualbox.org/},
>  The VirtualBox PC virtualizer.
>  
> -@item [13]
> +@item [10]
>  @url{http://www.xen.org/},
>  The Xen hypervisor.
>  
> -@item [14]
> -@url{http://kvm.qumranet.com/kvmwiki/Front_Page},
> +@item [11]
> +@url{http://www.linux-kvm.org/},
>  Kernel Based Virtual Machine (KVM).
>  
> -@item [15]
> +@item [12]
>  @url{http://www.greensocs.com/projects/QEMUSystemC},
>  QEMU-SystemC, a hardware co-simulator.
>  
> 

Applied, thanks.

Paolo