ia64/xen-unstable

changeset 744:57012a0c028c

bitkeeper revision 1.444 (3f6b38d7qamTogSmHdj52H60KzAVVQ)

readme fixes
author iap10@labyrinth.cl.cam.ac.uk
date Fri Sep 19 17:11:51 2003 +0000 (2003-09-19)
parents 86ea0e2fba1d
children 52f228c7096b
files README README.CD
line diff
     1.1 --- a/README	Fri Sep 19 16:34:38 2003 +0000
     1.2 +++ b/README	Fri Sep 19 17:11:51 2003 +0000
     1.3 @@ -32,36 +32,36 @@ Xen has since grown into a project in it
     1.4  investigate interesting research issues regarding the best techniques
     1.5  for virtualizing resources such as the CPU, memory, disk and network.
     1.6  The project has been bolstered by support from Intel Research
     1.7 -Cambridge, who are now working closely with us. We've now also
     1.8 -received support from Microsoft Research Cambridge to port Windows XP
     1.9 -to run on Xen.
    1.10 +Cambridge, who are now working closely with us. We're also in receipt
    1.11 +of support from Microsoft Research Cambridge to port Windows XP to 
    1.12 +run on Xen.
    1.13  
    1.14 -Xen enables multiple operating system images to be run simultaneously
    1.15 +Xen enables multiple operating system images to execute concurrently 
    1.16  on the same hardware with very low performance overhead --- much lower
    1.17 -than commercial offerings on the same x86 platform.
    1.18 +than commercial offerings for the same x86 platform.
    1.19  
    1.20  This is achieved by requiring OSs to be specifically ported to run on
    1.21  Xen, rather than allowing unmodified OS images to be used. Crucially,
    1.22  only the OS needs to be changed -- all of the user-level application
    1.23 -binaries, libraries etc can run unmodified. Hence, the modified OS
    1.24 +binaries, libraries etc can run unmodified. Hence the modified OS
    1.25  kernel can typically just be dropped into any existing OS distribution
    1.26  or installation.
    1.27  
    1.28  Xen currently runs on the x86 architecture, but could in principle be
    1.29 -ported to other CPUs. In fact, it would have been rather easier to
    1.30 -write Xen for pretty much any other architecture as x86 doesn't do us
    1.31 -any favours at all. The best description of Xen's deign,
    1.32 -implementation and performance is contained in our October 2003 SOSP
    1.33 -paper: http://www.cl.cam.ac.uk/netos/papers/2003-xensosp.pdf
    1.34 +ported to others. In fact, it would have been rather easier to write
    1.35 +Xen for pretty much any other architecture as x86 is particularly 
    1.36 +tricky to handle. A good description of Xen's design, implementation 
    1.37 +and performance is contained in our October 2003 SOSP paper, available
    1.38 +at http://www.cl.cam.ac.uk/netos/papers/2003-xensosp.pdf
    1.39  
    1.40  We have been working on porting 3 different operating systems to run
    1.41  on Xen: Linux 2.4, Windows XP, and NetBSD.
    1.42  
    1.43  The Linux 2.4 port (currently Linux 2.4.22) works very well -- we
    1.44  regularly use it to host complex applications such as PostgreSQL,
    1.45 -Apache, BK servers etc. It runs all user-space applications we've
    1.46 +Apache, BK servers etc. It runs every user-space applications we've
    1.47  tried.  We refer to our version of Linux ported to run on Xen as
    1.48 -"XenoLinux", through really it's just standard Linux ported to a new
    1.49 +"XenoLinux", although really it's just standard Linux ported to a new
    1.50  virtual CPU architecture that we call xeno-x86 (abbreviated to just
    1.51  "xeno").
    1.52  
    1.53 @@ -78,8 +78,8 @@ source and binaries to anyone that has s
    1.54  source license, which these days has very reasonable terms. We are in
    1.55  discussions with Microsoft about the possibility of being able to make
    1.56  binary releases to a larger user community. Obviously, there are
    1.57 -issues with product activation in this environment and such like,
    1.58 -which need to be thought through.
    1.59 +issues with product activation in this environment which need to be 
    1.60 +thought through.
    1.61  
    1.62  So, for the moment, you only get to run multiple copies of Linux on
    1.63  Xen, but we hope this will change before too long.  Even running
    1.64 @@ -88,7 +88,7 @@ means of containing faults to one OS ima
    1.65  performance isolation between the various OS, enabling you to either
    1.66  restrict, or reserve resources for, particular VM instances.
    1.67  
    1.68 -Its also useful for development -- each version of Linux can have
    1.69 +It's also useful for development -- each version of Linux can have
    1.70  different patches applied, enabling different kernels to be tried
    1.71  out. For example, the "vservers" patch used by PlanetLab applies
    1.72  cleanly to our ported version of Linux.
    1.73 @@ -109,26 +109,37 @@ for us to write drivers for "legacy" har
    1.74  Xen requires a "P6" or newer processor (e.g. Pentium Pro, Celeron,
    1.75  Pentium II, Pentium III, Pentium IV, Xeon, AMD Athlon, AMD Duron).
    1.76  Multiprocessor machines are supported, and we also have basic support
    1.77 -for HyperThreading (SMT), though this remains a topic for ongoing
    1.78 +for HyperThreading (SMT), although this remains a topic for ongoing
    1.79  research. We're also looking at an AMD x86_64 port (though it should
    1.80 -run on Opterons in 32 bit mode just fine).
    1.81 +run on Opterons in 32-bit mode just fine).
    1.82  
    1.83 -Xen can currently use up to 4GB of memory. Its possible for x86
    1.84 +Xen can currently use up to 4GB of memory. It's possible for x86
    1.85  machines to address more than that (64GB), but it requires using a
    1.86  different page table format (3-level rather than 2-level) that we
    1.87  currently don't support. Adding 3-level PAE support wouldn't be
    1.88  difficult, but we'd also need to add support to all the guest
    1.89  OSs. Volunteers welcome!
    1.90  
    1.91 -We currently support a relative modern set of network cards: Intel
    1.92 +We currently support a relatively modern set of network cards: Intel
    1.93  e1000, Broadcom BCM 57xx (tg3), 3COM 3c905 (3c59x). Adding support for
    1.94  other NICs that support hardware DMA scatter/gather from half-word
    1.95 -aligned addresses is relatively straight forward, by porting the
    1.96 +aligned addresses is relatively straightforward, by porting the
    1.97  equivalent Linux driver. Drivers for a number of other older cards
    1.98  have recently been added [pcnet32, e100, tulip], but are untested and
    1.99  not recommended.
   1.100  
   1.101  
   1.102 +Building Xen and XenoLinux
   1.103 +==========================
   1.104 +
   1.105 +Take a look at the tools/misc/xen-clone script in the BK repository,
   1.106 +which will 'bk clone' the live master tree, and then set about 
   1.107 +building everything. The build procedure for xenolinux is slightly 
   1.108 +complicated as its done by running the 'mkbuildtree' script over
   1.109 +a pristine Linux tree to patch it for xenolinux.
   1.110 +
   1.111 +
   1.112 +
   1.113  Ian Pratt
   1.114  9 Sep 2003
   1.115  
     2.1 --- a/README.CD	Fri Sep 19 16:34:38 2003 +0000
     2.2 +++ b/README.CD	Fri Sep 19 17:11:51 2003 +0000
     2.3 @@ -19,10 +19,10 @@ Executive Summary
     2.4  =================
     2.5  
     2.6  This CD is a standalone demo of the Xen Virtual Machine Monitor (VMM)
     2.7 -and Linux-2.4 OS port (xenolinux). It runs entirely off the CD,
     2.8 -without requiring hard disk installation. This is acheived using a ram
     2.9 +and Linux-2.4 OS port (XenoLinux). It runs entirely off the CD,
    2.10 +without requiring hard disk installation. This is achieved using a RAM
    2.11  disk to store mutable file system data while using the CD for
    2.12 -everything else. The CD can also be used for installing Xen/xenolinux
    2.13 +everything else. The CD can also be used for installing Xen/XenoLinux
    2.14  to disk, and includes a source code snapshot along with all of the
    2.15  tools required to build it.
    2.16  
    2.17 @@ -30,7 +30,7 @@ Booting the CD
    2.18  ==============
    2.19  
    2.20  The Xen VMM is currently fairly h/w specific, but porting new device
    2.21 -drivers is relatively straight forward thanks to Xen's Linux driver
    2.22 +drivers is relatively straightforward thanks to Xen's Linux driver
    2.23  compatibility layer. The current snapshot supports the following
    2.24  hardware:
    2.25  
    2.26 @@ -38,15 +38,15 @@ CPU:  Pentium Pro/II/III/IV/Xeon, Athlon
    2.27  IDE:  Intel PIIX chipset, others will be PIO only (slow)
    2.28  SCSI: Adaptec / Dell PERC Raid (aacraid), megaraid, Adaptec aic7xxx
    2.29  Net:  Recommended: Intel e1000, Broadcom BCM57xx (tg3), 3c905 (3c59x)
    2.30 -      Tested but requires extra copies : pcnet32, Intel e100
    2.31 +      Tested but require extra copies : pcnet32, Intel e100
    2.32        Untested and also requires extra copies : tulip
    2.33  
    2.34 -Because of the demo CD's use of ram disks, make sure you have plenty
    2.35 +Because of the demo CD's use of RAM disks, make sure you have plenty
    2.36  of RAM (256MB+).
    2.37  
    2.38  To try out the Demo, boot from CD (you may need to change your BIOS
    2.39  configuration to do this), hit a key on either the keyboard or serial
    2.40 -line to pull up the Grub boot menu, then select one of the four boot
    2.41 +line to pull up the Grub boot menu, then select one of the three boot
    2.42  options:
    2.43  
    2.44   Xen / linux-2.4.22 
    2.45 @@ -59,19 +59,19 @@ problems. If you are going for a command
    2.46  the grub menu, then edit the "ip=" parameters to reflect your setup
    2.47  e.g. "ip=<ipaddr>::<gateway>:<netmask>::eth0:off". It shouldn't be
    2.48  necessary to set either the nfs server or hostname
    2.49 -parameters. Alternatively, once xenolinux has booted you can login and
    2.50 +parameters. Alternatively, once XenoLinux has booted you can login and
    2.51  setup networking with 'dhclient' or 'ifconfig' and 'route' in the
    2.52  normal way.
    2.53  
    2.54 -To make things easier for yourself, its worth trying to arrange for an
    2.55 +To make things easier for yourself, it's worth trying to arrange for an
    2.56  IP address which is the first in a sequential range of free IP
    2.57 -addresses.  Its useful to give each VM instance its own public IP
    2.58 -address (though it is possible to do NAT or use private addresses
    2.59 -etc), and the configuration files on the CD allocate IP addresses
    2.60 +addresses.  It's useful to give each VM instance its own public IP
    2.61 +address (though it is possible to do NAT or use private addresses), 
    2.62 +and the configuration files on the CD allocate IP addresses
    2.63  sequentially for subsequent domains unless told otherwise.
    2.64  
    2.65  After selecting the kernel to boot, stand back and watch Xen boot,
    2.66 -closely followed by "domain 0" running the xenolinux kernel. The boot
    2.67 +closely followed by "domain 0" running the XenoLinux kernel. The boot
    2.68  messages are also sent to the serial line (the baud rate can be set on
    2.69  the Xen cmdline, but defaults to 115200), which can be very useful for
    2.70  debugging should anything important scroll off the screen. Xen's
    2.71 @@ -91,10 +91,10 @@ best to start by configuring networking,
    2.72  manually via ifconfig and route, remembering to edit /etc/resolv.conf
    2.73  if you want DNS.
    2.74  
    2.75 -You can start an xserver with 'startx'. It defaults to a conservative
    2.76 +You can start an X server with 'startx'. It defaults to a conservative
    2.77  1024x768, but you can edit the script for higher resoloutions.  The CD
    2.78  contains a load of standard software. You should be able to start
    2.79 -Apache, PostgreSQL, Mozzila etc in the normal way, the because
    2.80 +Apache, PostgreSQL, Mozzila etc in the normal way, but because
    2.81  everything is running off CD the performance will be very sluggish and
    2.82  you may run out of memory for the 'tmpfs' file system.  You may wish
    2.83  to go ahead and install Xen/XenoLinux on your hard drive, either
    2.84 @@ -102,7 +102,7 @@ dropping Xen and the XenoLinux kernel do
    2.85  distribution, or using the file systems from the CD (which are based
    2.86  on RH9). See the installation instructions later in this document.
    2.87  
    2.88 -If you want to browse the Xen / Xenolinux source, it's all located
    2.89 +If you want to browse the Xen / XenoLinux source, it's all located
    2.90  under /usr/local/src, complete with BitKeeper repository. We've also
    2.91  included source code and configuration information for the various
    2.92  benchmarks we used in the SOSP paper.
    2.93 @@ -116,12 +116,14 @@ but since we generally use the command l
    2.94  rather better debugged at present. The key command is 'xenctl' which
    2.95  lives in /usr/local/bin and uses /etc/xenctl.xml for its default
    2.96  configuration. Run 'xenctl' without any arguments to get a help
    2.97 -message.
    2.98 +message. Note that xenctl is a java front end to various underlying 
    2.99 +internal tools written in C (xi_*). Running off CD, it seems to take 
   2.100 +an age to start...
   2.101  
   2.102 -The first thing to do is to set up a window in which you will receive
   2.103 -console output from other domains. Console output will arrive as UDP
   2.104 -packets destined for 169.254.1.0, so its necessary to setup an alias
   2.105 -on eth0. The easiest way to do this is to run:
   2.106 +Abyway, the first thing to do is to set up a window in which you will
   2.107 +receive console output from other domains. Console output will arrive
   2.108 +as UDP packets destined for 169.254.1.0, so its necessary to setup an
   2.109 +alias on eth0. The easiest way to do this is to run:
   2.110  
   2.111    xen_nat_enable
   2.112  
   2.113 @@ -136,27 +138,24 @@ Next, run a the xen UDP console displaye
   2.114    xen_read_console &
   2.115  
   2.116  
   2.117 -The tool used for starting and controlling domains is 'xenctl'. It's a
   2.118 -java front end to various underlying internal tools written in C
   2.119 -(xi_*). Running off CD, it seems to take an age to start...
   2.120 +As mentioned above, xenctl uses /etc/xenctl.xml as its default
   2.121 +configuration. The directory contains two different configs depending
   2.122 +on whether you want to use NAT, or multiple sequential external IPs
   2.123 +(it's possible to override any of the parameters on the command line
   2.124 +if you want to set specific IPs, etc).
   2.125  
   2.126 -xenctl uses /etc/xenctl.xml as its default configuration. The
   2.127 -directory contains two different configs depending on whether you want
   2.128 -to use NAT, or multiple sequential external IPs (its possible to
   2.129 -override any of the parameters on the command line, if you want to set
   2.130 -specific IPs etc).
   2.131 +The default configuration file supports NAT. To change to use multiple IPs:
   2.132  
   2.133 -The default file supports NAT. To change to use multiple IPs:
   2.134   cp /etc/xenctl.xml-publicip /etc/xenctl.xml
   2.135  
   2.136 -A sequence of commands must be given to xenctl to start a
   2.137 +A sequence of commands must be given to xenctl to start a new 
   2.138  domain. First a new domain must be created, which requires specifying
   2.139  the initial memory allocation, the kernel image to use, and the kernel
   2.140  command line. As well as the root file system details, you'll need to
   2.141  set the IP address on the command line: since Xen currently doesn't
   2.142  support a virtual console for domains >1, you won't be able to log to
   2.143  your new domain unless you've got networking configured and an sshd
   2.144 -running! (using dhcp for new domains should work too.)
   2.145 +running! (using dhcp for new domains should work too).
   2.146  
   2.147  After creating the domain, xenctl must be used to grant the domain
   2.148  access to other resources such as physical or virtual disk partions.
   2.149 @@ -171,7 +170,7 @@ referring to (-nX). To use the sample sc
   2.150  You should see the domain booting on your xen_read_console window.
   2.151  
   2.152  The xml defaults start another domain running off the CD, using a
   2.153 -separate ram based file system for mutable data in root (just like
   2.154 +separate RAM-based file system for mutable data in root (just like
   2.155  domain 0). 
   2.156  
   2.157  The new domain is started with a '4' on the kernel command line to
   2.158 @@ -179,7 +178,7 @@ tell 'init' to go to runlevel 4 rather t
   2.159  done simply to suppress a bunch of harmless error messages that would
   2.160  otherwise occur when the new (unprivileged) domain tried to access
   2.161  physical hardware resources to try setting the hwclock, system font,
   2.162 -gpm etc.
   2.163 +run gpm etc.
   2.164  
   2.165  After it's booted, you should be able to ssh into your new domain. If
   2.166  you went for a NATed address, from domain 0 you should be able to ssh
   2.167 @@ -201,14 +200,14 @@ xenctl to 'stop' (pause) a domain, or 'k
   2.168  kill it nicely by sending a shutdown event and waiting for it to
   2.169  terminate, or blow the sucker away with extreme prejudice. 
   2.170  
   2.171 -If you want to configure the new domain differently, type 'xenctl' to
   2.172 +If you want to configure a new domain differently, type 'xenctl' to
   2.173  get a list of arguments, e.g. at the 'xenctl domain new' command line
   2.174  use the "-4" option to set a diffrent IPv4 address. 
   2.175  
   2.176  xenctl can be used to set the new kernel's command line, and hence
   2.177 -determine what it uses as a root file system etc. Although the default
   2.178 +determine what it uses as a root file system, etc. Although the default
   2.179  is to boot in the same manner that domain0 did (using the RAM-based
   2.180 -file system for root and the CD for usr) it's possible to configure any
   2.181 +file system for root and the CD for /usr) it's possible to configure any
   2.182  of the following possibilities, for example:
   2.183  
   2.184   * initrd=/boot/initrd init=/linuxrc
   2.185 @@ -219,7 +218,7 @@ of the following possibilities, for exam
   2.186  
   2.187   * root=/dev/xvda1 ro
   2.188       boot using a pre-configured 'virtual block device' that will be
   2.189 -     attached to a virtual disk that will previously had a file system
   2.190 +     attached to a virtual disk that previously has had a file system
   2.191       installed on it.
   2.192  
   2.193   * root=/dev/nfs nfsroot=/path/on/server ip=<blah_including server_IP>
   2.194 @@ -234,18 +233,18 @@ read-only usr partition might make sense
   2.195  
   2.196  Alternatively, you can use 'virtual disks', which are stored as files
   2.197  within a custom file system. "xenctl partitions add" can be used to
   2.198 -'format' a partition with the file system, then virtual disks can be
   2.199 -created with "xenctl vd create". Virtual disks can then be attached to
   2.200 -a running domain as a 'virtual block device' using "xenctl vdb
   2.201 -create". The virtual disk can then optionally be partitioned
   2.202 -(e.g. "fdisk /dev/xvda") or have a file system created on it directly
   2.203 -(e.g. "mkfs -t ext3 /dev/xvda").  The virtual disk can then accessed
   2.204 -by a virtual block device associated with another domain, and even
   2.205 -used as a boot device.
   2.206 +'format' a partition with the file system, and then virtual disks can
   2.207 +be created with "xenctl vd create". Virtual disks can then be attached
   2.208 +to a running domain as a 'virtual block device' using "xenctl vdb
   2.209 +create". The virtual disk can optionally be partitioned (e.g. "fdisk
   2.210 +/dev/xvda") or have a file system created on it directly (e.g. "mkfs
   2.211 +-t ext3 /dev/xvda").  The virtual disk can then be accessed by a
   2.212 +virtual block device associated with another domain, and even used as
   2.213 +a boot device.
   2.214  
   2.215  Both virtual disks and real partitions should only be shared between
   2.216  domains in a read-only fashion otherwise the linux kernels will
   2.217 -obviously get very confused if the file system structure changes
   2.218 +obviously get very confused as the file system structure may change
   2.219  underneath them (having the same partition mounted rw twice is a sure
   2.220  fire way to cause irreparable damage)!  If you want read-write
   2.221  sharing, export the directory to other domains via NFS from domain0.
   2.222 @@ -254,12 +253,13 @@ sharing, export the directory to other d
   2.223  About The Xen Demo CD
   2.224  =====================
   2.225  
   2.226 -The purpose of the Demo CD is to distribute a snapshot of Xen's source,
   2.227 -and simultaneously provide a convenient means for enabling people to
   2.228 -get experience playing with Xen without needing to install it on their
   2.229 -hard drive. If you decide to install Xen/XenoLinux you can do so
   2.230 -simply by following the INSTALL instructions and copying the contents of
   2.231 -the CD on to a suitably formated disk partition and install the Grub
   2.232 +The purpose of the Demo CD is to distribute a snapshot of Xen's
   2.233 +source, and simultaneously provide a convenient means for enabling
   2.234 +people to get experience playing with Xen without needing to install
   2.235 +it on their hard drive. If you decide to install Xen/XenoLinux you can
   2.236 +do so simply by following the installation instructions below -- which
   2.237 +essentially involves copying the contents of the CD on to a suitably
   2.238 +formated disk partition, and then installing or updating the Grub
   2.239  bootloader.
   2.240  
   2.241  This is a bootable CD that loads Xen, and then a Linux 2.4.22 OS image
   2.242 @@ -269,7 +269,7 @@ the RedHat 9 distribution that is able t
   2.243  /var etc). Changes you make to the tmpfs will obviously not be
   2.244  persistent across reboots!
   2.245  
   2.246 -Because of the use of a ram-based file system for root, you'll need
   2.247 +Because of the use of a RAM-based file system for root, you'll need
   2.248  plenty of memory to run this CD -- something like 96MB per VM. This is
   2.249  not a restriction of Xen : once you've installed Xen, XenoLinux and
   2.250  the file system images on your hard drive you'll find you can boot VMs
   2.251 @@ -277,10 +277,10 @@ in just a few MBs.
   2.252  
   2.253  The CD contains a snapshot of the Xen and XenoLinux code base that we
   2.254  believe to be pretty stable, but lacks some of the features that are
   2.255 -currently still work in progress e.g. OS suspend/resume to file, and
   2.256 +currently still work in progress e.g. OS suspend/resume to disk, and
   2.257  various memory management enhancements to provide fast inter-OS
   2.258  communication and sharing of memory pages between OSs. We'll release
   2.259 -newer snapshots as required, in the form of a BitKeeper repository
   2.260 +newer snapshots as required, making use of a BitKeeper repository
   2.261  hosted on http://xen.bkbits.net (follow instructions from the project
   2.262  home page).  We're obviously grateful to receive any bug fixes or
   2.263  other code you can contribute. We suggest you join the
   2.264 @@ -314,7 +314,7 @@ title Xen / XenoLinux 2.4.22
   2.265          kernel /boot/image.gz dom0_mem=131072 ser_baud=115200 noht
   2.266          module /boot/xenolinux.gz root=/dev/sda4 ro console=tty0
   2.267  
   2.268 -The first line specifies which xen image to use, and what command line
   2.269 +The first line specifies which Xen image to use, and what command line
   2.270  arguments to pass to Xen. In this case, we set the maximum amount of
   2.271  memory to allocate to domain0, and the serial baud rate (the default
   2.272  is 9600 baud). We could also disable smp support (nosmp) or disable
   2.273 @@ -328,7 +328,7 @@ case, we're configuring the root partiti
   2.274  be mounted read-only (normal practice). 
   2.275  
   2.276  If we were booting with an initial ram disk (initrd), then this would
   2.277 -require a second "module" line, with no arguments.
   2.278 +require a second "module" line.
   2.279  
   2.280  
   2.281  Installing the file systems from the CD
   2.282 @@ -348,7 +348,7 @@ Next, mount the file system(s) e.g.:
   2.283    mkdir /mnt/root && mount /dev/hda3 /mnt/root
   2.284    [mkdir /mnt/usr && mount /dev/hda4 /mnt/usr]
   2.285    
   2.286 -To install the root file system, simply untar /usr/XenDemoCD/root.tar.gz
   2.287 +To install the root file system, simply untar /usr/XenDemoCD/root.tar.gz:
   2.288    cd /mnt/root && tar -zxpf /usr/XenDemoCD/root.tar.gz
   2.289  
   2.290  You'll need to edit /mnt/root/etc/fstab to reflect your file system
   2.291 @@ -360,7 +360,7 @@ though leaving out the "XenDemoCD" and "
   2.292    cd /usr && cp -a X11R6 etc java libexec root src bin dict kerberos local sbin tmp doc include lib man share /mnt/usr
   2.293  
   2.294  If you intend to boot off these file systems (i.e. use them for
   2.295 -domain0), then you probably want to copy the /usr/boot directory on
   2.296 +domain 0), then you probably want to copy the /usr/boot directory on
   2.297  the cd over the top of the current symlink to /boot on your root
   2.298  filesystem (after deleting the current symlink) i.e.:
   2.299    cd /mnt/root ; rm boot ; cp -a /usr/boot .
   2.300 @@ -368,6 +368,7 @@ filesystem (after deleting the current s
   2.301  The XenDemoCD directory is only useful if you want to build your own
   2.302  version of the XenDemoCD (see below).
   2.303  
   2.304 +
   2.305  Debugging
   2.306  ---------
   2.307  
   2.308 @@ -375,15 +376,16 @@ Xen has a set of debugging features that
   2.309  figure out what's going on. Hit 'h' on the serial line or ScrollLock-h
   2.310  on the keyboard to get a list of supported commands. 
   2.311  
   2.312 -If you have a crash you'll likely get a crash dump containing and EIP
   2.313 -(PC), which along with and 'objdump -d image' can be useful in
   2.314 -figuring out what's happened.  Debug a xenolinux image just as you
   2.315 +If you have a crash you'll likely get a crash dump containing an EIP
   2.316 +(PC) which, along with an 'objdump -d image', can be useful in
   2.317 +figuring out what's happened.  Debug a XenoLinux image just as you
   2.318  would any other Linux kernel.
   2.319  
   2.320 +
   2.321  Description of how the XenDemoCD boots
   2.322  --------------------------------------
   2.323  
   2.324 -1. Grub is used to load Xen, a xenolinux kernel, and an initrd (initial
   2.325 +1. Grub is used to load Xen, a XenoLinux kernel, and an initrd (initial
   2.326  ram disk). [The source of the version of Grub used is in /usr/local/src]
   2.327  
   2.328  2. the init=/linuxrc command line causes linux to execute /linuxrc in
   2.329 @@ -394,7 +396,7 @@ locations : /dev/hd[abcd].
   2.330  
   2.331  4. it then creates a 'tmpfs' file system and untars the
   2.332  'XenDemoCD/root.tar.gz' file into the tmpfs. This contains hopefully
   2.333 -all the files that need to be mutable. (this would be so much easier
   2.334 +all the files that need to be mutable (this would be so much easier
   2.335  if Linux supported 'stacked' or union file systems...)
   2.336  
   2.337  5. Next, /linuxrc uses the pivot_root call to change the root file
   2.338 @@ -407,7 +409,7 @@ normally.
   2.339  Building your own version of the XenDemoCD
   2.340  ------------------------------------------
   2.341  
   2.342 -The 'live ISO' version of RedHat isbased heavily on Peter Anvin's
   2.343 +The 'live ISO' version of RedHat is based heavily on Peter Anvin's
   2.344  SuperRescue CD version 2.1.2 and J. McDaniel's Plan-B:
   2.345  
   2.346   http://www.kernel.org/pub/dist/superrescue/v2/
   2.347 @@ -461,22 +463,27 @@ echo '<put_your_name_here>' > Builder
   2.348  This process can take 30 mins even on a fast machine, but you should
   2.349  eventually end up with an iso image in the build directory.
   2.350  
   2.351 -notes:
   2.352 -
   2.353 -root - the root of the file system heirarchy as presented to the running system
   2.354 -
   2.355 -rootpatch - contains files that have been modified from the standard RH, and copied over the root tree as part of the build procedure.
   2.356 -
   2.357 -irtree - the filie system tree that will go into the initrd (initial ram disk)
   2.358 +Notes:
   2.359  
   2.360 -work - a working directory used in the build process
   2.361 +  root      - the root of the file system heirarchy as presented to the
   2.362 +              running system
   2.363  
   2.364 -usr - this should really be in 'work' as its created as part of the
   2.365 -build process. It contains the 'immutable' files that will be served
   2.366 -from the CD rather than the tmpfs containing the contents of root.tar.gz
   2.367 -Some files that are normally in /etc or /var that are large and
   2.368 -actually unlikely to need changing have been moved into /usr/root
   2.369 -and replaced with links.
   2.370 +  rootpatch - contains files that have been modified from the standard
   2.371 +              RH, and copied over the root tree as part of the build
   2.372 +              procedure.
   2.373 +
   2.374 +  irtree    - the file system tree that will go into the initrd (initial
   2.375 +              ram disk)
   2.376 +
   2.377 +  work      - a working directory used in the build process
   2.378 +
   2.379 +  usr       - this should really be in 'work' as its created as part of the
   2.380 +              build process. It contains the 'immutable' files that will
   2.381 +              be served from the CD rather than the tmpfs containing the
   2.382 +              contents of root.tar.gz. Some files that are normally in /etc 
   2.383 +              or /var that are large and actually unlikely to need changing 
   2.384 +              have been moved into /usr/root and replaced with links.
   2.385 +
   2.386  
   2.387  Ian Pratt
   2.388  9 Sep 2003
   2.389 \ No newline at end of file