OvmfPkg/README

   1
   2 === OVMF OVERVIEW ===
   3
   4 The Open Virtual Machine Firmware (OVMF) project aims
   5 to support firmware for Virtual Machines using the edk2
   6 code base.  More information can be found at:
   7
   8 http://www.tianocore.org/ovmf/
   9
  10 === STATUS ===
  11
  12 Current capabilities:
  13 * IA32 and X64 architectures
  14 * QEMU (0.10.0 or later)
  15   - Video, keyboard, IDE, CD-ROM, serial
  16   - Runs UEFI shell
  17   - Optional NIC support.  Requires QEMU (0.12.2 or later)
  18 * UEFI Linux boots
  19 * UEFI Windows 8 boots
  20 * UEFI Windows 7 & Windows 2008 Server boot (see important notes below!)
  21
  22 === FUTURE PLANS ===
  23
  24 * Test/Stabilize UEFI Self-Certification Tests (SCT) results
  25
  26 === BUILDING OVMF ===
  27
  28 Pre-requisites:
  29 * Build environment capable of build the edk2 MdeModulePkg.
  30 * A properly configured ASL compiler:
  31   - Intel ASL compiler: Available from http://www.acpica.org
  32   - Microsoft ASL compiler: Available from http://www.acpi.info
  33 * NASM: http://www.nasm.us/
  34
  35 Update Conf/target.txt ACTIVE_PLATFORM for OVMF:
  36                              PEI arch   DXE arch   UEFI interfaces
  37 * OvmfPkg/OvmfPkgIa32.dsc      IA32       IA32           IA32
  38 * OvmfPkg/OvmfPkgIa32X64.dsc   IA32       X64            X64
  39 * OvmfPkg/OvmfPkgX64.dsc       X64        X64            X64
  40
  41 Update Conf/target.txt TARGET_ARCH based on the .dsc file:
  42                              TARGET_ARCH
  43 * OvmfPkg/OvmfPkgIa32.dsc     IA32
  44 * OvmfPkg/OvmfPkgIa32X64.dsc  IA32 X64
  45 * OvmfPkg/OvmfPkgX64.dsc      X64
  46
  47 Following the edk2 build process, you will find the OVMF binaries
  48 under the $WORKSPACE/Build/*/*/FV directory.  The actual path will
  49 depend on how your build is configured.  You can expect to find
  50 these binary outputs:
  51 * OVMF.FD
  52   - Please note!  This filename has changed.  Older releases used OVMF.Fv.
  53 * OvmfVideo.rom
  54   - This file is not built separately any longer, starting with svn r13520.
  55
  56 More information on building OVMF can be found at:
  57
  58 https://github.com/tianocore/tianocore.github.io/wiki/How%20to%20build%20OVMF
  59
  60 === RUNNING OVMF on QEMU ===
  61
  62 * QEMU 0.12.2 or later is required.
  63 * Be sure to use qemu-system-x86_64, if you are using and X64 firmware.
  64   (qemu-system-x86_64 works for the IA32 firmware as well, of course.)
  65 * Use OVMF for QEMU firmware (3 options available)
  66   - Option 1: QEMU 1.6 or newer; Use QEMU -pflash parameter
  67     * QEMU/OVMF will use emulated flash, and fully support UEFI variables
  68     * Run qemu with: -pflash path/to/OVMF.fd
  69     * Note that this option is required for running SecureBoot-enabled builds
  70       (-D SECURE_BOOT_ENABLE).
  71   - Option 2: Use QEMU -bios parameter
  72     * Note that UEFI variables will be partially emulated, and non-volatile
  73       variables may lose their contents after a reboot
  74     * Run qemu with: -bios path/to/OVMF.fd
  75   - Option 3: Use QEMU -L parameter
  76     * Note that UEFI variables will be partially emulated, and non-volatile
  77       variables may lose their contents after a reboot
  78     * Either copy, rename or symlink OVMF.fd => bios.bin
  79     * Use the QEMU -L parameter to specify the directory where the bios.bin
  80       file is located.
  81 * The EFI shell is built into OVMF builds at this time, so it should
  82   run automatically if a UEFI boot application is not found on the
  83   removable media.
  84 * On Linux, newer version of QEMU may enable KVM feature, and this might
  85   cause OVMF to fail to boot.  The QEMU '-no-kvm' may allow OVMF to boot.
  86 * Capturing OVMF debug messages on qemu:
  87   - The default OVMF build writes debug messages to IO port 0x402.  The
  88     following qemu command line options save them in the file called
  89     debug.log: '-debugcon file:debug.log -global isa-debugcon.iobase=0x402'.
  90   - It is possible to revert to the original behavior, when debug messages were
  91     written to the emulated serial port (potentially intermixing OVMF debug
  92     output with UEFI serial console output).  For this the
  93     '-D DEBUG_ON_SERIAL_PORT' option has to be passed to the build command (see
  94     the next section), and in order to capture the serial output qemu needs to
  95     be started with eg. '-serial file:serial.log'.
  96   - Debug messages fall into several categories.  Logged vs. suppressed
  97     categories are controlled at OVMF build time by the
  98     'gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel' bitmask (an UINT32
  99     value) in the selected .dsc file.  Individual bits of this bitmask are
 100     defined in <MdePkg/Include/Library/DebugLib.h>.  One non-default bit (with
 101     some performance impact) that is frequently set for debugging is 0x00400000
 102     (DEBUG_VERBOSE).
 103   - The RELEASE build target ('-b RELEASE' build option, see below) disables
 104     all debug messages.  The default build target is DEBUG.
 105
 106 === Build Scripts ===
 107
 108 On systems with the bash shell you can use OvmfPkg/build.sh to simplify
 109 building and running OVMF.
 110
 111 So, for example, to build + run OVMF X64:
 112 $ OvmfPkg/build.sh -a X64
 113 $ OvmfPkg/build.sh -a X64 qemu
 114
 115 And to run a 64-bit UEFI bootable ISO image:
 116 $ OvmfPkg/build.sh -a X64 qemu -cdrom /path/to/disk-image.iso
 117
 118 To build a 32-bit OVMF without debug messages using GCC 4.5:
 119 $ OvmfPkg/build.sh -a IA32 -b RELEASE -t GCC45
 120
 121 === SMM support ===
 122
 123 Requirements:
 124 * SMM support requires QEMU 2.5.
 125 * The minimum required QEMU machine type is "pc-q35-2.5".
 126 * SMM with KVM requires Linux 4.4 (host).
 127
 128 OVMF is capable of utilizing SMM if the underlying QEMU or KVM hypervisor
 129 emulates SMM. SMM is put to use in the S3 suspend and resume infrastructure,
 130 and in the UEFI variable driver stack. The purpose is (virtual) hardware
 131 separation between the runtime guest OS and the firmware (OVMF), with the
 132 intent to make Secure Boot actually secure, by preventing the runtime guest OS
 133 from tampering with the variable store and S3 areas.
 134
 135 For SMM support, OVMF must be built with the "-D SMM_REQUIRE" option. The
 136 resultant firmware binary will check if QEMU actually provides SMM emulation;
 137 if it doesn't, then OVMF will log an error and trigger an assertion failure
 138 during boot (even in RELEASE builds). Both the naming of the flag (SMM_REQUIRE,
 139 instead of SMM_ENABLE), and this behavior are consistent with the goal
 140 described above: this is supposed to be a security feature, and fallbacks are
 141 not allowed. Similarly, a pflash-backed variable store is a requirement.
 142
 143 QEMU should be started with the options listed below (in addition to any other
 144 guest-specific flags). The command line should be gradually composed from the
 145 hints below. '\' is used to extend the command line to multiple lines, and '^'
 146 can be used on Windows.
 147
 148 * QEMU binary and options specific to 32-bit guests:
 149
 150   $ qemu-system-i386 -cpu coreduo,-nx \
 151
 152   or
 153
 154   $ qemu-system-x86_64 -cpu <MODEL>,-lm,-nx \
 155
 156 * QEMU binary for running 64-bit guests (no particular options):
 157
 158   $ qemu-system-x86_64 \
 159
 160 * Flags common to all SMM scenarios (only the Q35 machine type is supported):
 161
 162   -machine q35,smm=on,accel=(tcg|kvm) \
 163   -m ... \
 164   -smp ... \
 165   -global driver=cfi.pflash01,property=secure,value=on \
 166   -drive if=pflash,format=raw,unit=0,file=OVMF_CODE.fd,readonly=on \
 167   -drive if=pflash,format=raw,unit=1,file=copy_of_OVMF_VARS.fd \
 168
 169 * In order to disable S3, add:
 170
 171   -global ICH9-LPC.disable_s3=1 \
 172
 173 === Network Support ===
 174
 175 OVMF provides a UEFI network stack by default. Its lowest level driver is the
 176 NIC driver, higher levels are generic. In order to make DHCP, PXE Boot, and eg.
 177 socket test utilities from the StdLib edk2 package work, (1) qemu has to be
 178 configured to emulate a NIC, (2) a matching UEFI NIC driver must be available
 179 when OVMF boots.
 180
 181 (If a NIC is configured for the virtual machine, and -- dependent on boot order
 182 -- PXE booting is attempted, but no DHCP server responds to OVMF's DHCP
 183 DISCOVER message at startup, the boot process may take approx. 3 seconds
 184 longer.)
 185
 186 * For each NIC emulated by qemu, a GPLv2 licensed UEFI driver is available from
 187   the iPXE project. The qemu source distribution, starting with version 1.5,
 188   contains prebuilt binaries of these drivers (and of course allows one to
 189   rebuild them from source as well). This is the recommended set of drivers.
 190
 191 * Use the qemu -netdev and -device options, or the legacy -net option, to
 192   enable NIC support: <http://wiki.qemu.org/Documentation/Networking>.
 193
 194 * For a qemu >= 1.5 binary running *without* any "-M machine" option where
 195   "machine" would identify a < qemu-1.5 configuration (for example: "-M
 196   pc-i440fx-1.4" or "-M pc-0.13"), the iPXE drivers are automatically available
 197   to and configured for OVMF in the default qemu installation.
 198
 199 * For a qemu binary in [0.13, 1.5), or a qemu >= 1.5 binary with an "-M
 200   machine" option where "machine" selects a < qemu-1.5 configuration:
 201
 202   - download a >= 1.5.0-rc1 source tarball from <http://wiki.qemu.org/Download>,
 203
 204   - extract the following iPXE driver files from the tarball and install them
 205     in a location that is accessible to qemu processes (this may depend on your
 206     SELinux configuration, for example):
 207
 208     qemu-VERSION/pc-bios/efi-e1000.rom
 209     qemu-VERSION/pc-bios/efi-ne2k_pci.rom
 210     qemu-VERSION/pc-bios/efi-pcnet.rom
 211     qemu-VERSION/pc-bios/efi-rtl8139.rom
 212     qemu-VERSION/pc-bios/efi-virtio.rom
 213
 214   - extend the NIC's -device option on the qemu command line with a matching
 215     "romfile=" optarg:
 216
 217     -device e1000,...,romfile=/full/path/to/efi-e1000.rom
 218     -device ne2k_pci,...,romfile=/full/path/to/efi-ne2k_pci.rom
 219     -device pcnet,...,romfile=/full/path/to/efi-pcnet.rom
 220     -device rtl8139,...,romfile=/full/path/to/efi-rtl8139.rom
 221     -device virtio-net-pci,...,romfile=/full/path/to/efi-virtio.rom
 222
 223 * Independently of the iPXE NIC drivers, the default OVMF build provides a
 224   basic virtio-net driver, located in OvmfPkg/VirtioNetDxe.
 225
 226 * Also independently of the iPXE NIC drivers, Intel's proprietary E1000 NIC
 227   driver (PROEFI) can be embedded in the OVMF image at build time:
 228
 229   - Download UEFI drivers for the e1000 NIC
 230     - http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=17515&lang=eng
 231     - Install the drivers into a directory called Intel3.5 in your WORKSPACE.
 232
 233   - Include the driver in OVMF during the build:
 234     - Add "-D E1000_ENABLE" to your build command,
 235     - For example: "build -D E1000_ENABLE".
 236
 237 * When a matching iPXE driver is configured for a NIC as described above, it
 238   takes priority over other drivers that could possibly drive the card too:
 239
 240                  | e1000  ne2k_pci  pcnet  rtl8139  virtio-net-pci
 241     -------------+------------------------------------------------
 242     iPXE         |   x       x        x       x           x
 243     VirtioNetDxe |                                        x
 244     Intel PROEFI |   x
 245
 246 === OVMF Flash Layout ===
 247
 248 Like all current IA32/X64 system designs, OVMF's firmware
 249 device (rom/flash) appears in QEMU's physical address space
 250 just below 4GB (0x100000000).
 251
 252 The layout of the firmware device in memory looks like:
 253
 254 +--------------------------------------- 4GB (0x100000000)
 255 | VTF0 (16-bit reset code) and OVMF SEC
 256 | (SECFV)
 257 +--------------------------------------- varies based on flash size
 258 |
 259 | Compressed main firmware image
 260 | (FVMAIN_COMPACT)
 261 |
 262 +--------------------------------------- base + 0x20000
 263 | Fault-tolerant write (FTW)
 264 | Spare blocks (64KB/0x10000)
 265 +--------------------------------------- base + 0x10000
 266 | FTW Work block (4KB/0x1000)
 267 +--------------------------------------- base + 0x0f000
 268 | Event log area (4KB/0x1000)
 269 +--------------------------------------- base + 0x0e000
 270 | Non-volatile variable storage
 271 | area (56KB/0xe000)
 272 +--------------------------------------- base address
 273
 274 OVMF supports building a 1MB or a 2MB flash image. The base address for
 275 a 1MB image in QEMU physical memory is 0xfff00000. The base address for
 276 a 2MB image is 0xffe00000.
 277
 278 The code in SECFV locates FVMAIN_COMPACT, and decompresses the
 279 main firmware (MAINFV) into RAM memory at address 0x800000. The
 280 remaining OVMF firmware then uses this decompressed firmware
 281 volume image.
 282
 283 === UNIXGCC Debug ===
 284
 285 If you build with the UNIXGCC toolchain, then debugging will be disabled
 286 due to larger image sizes being produced by the UNIXGCC toolchain. The
 287 first choice recommendation is to use GCC44 or newer instead.
 288
 289 If you must use UNIXGCC, then you can override the build options for
 290 particular libraries and modules in the .dsc to re-enable debugging
 291 selectively. For example:
 292   [Components]
 293   OvmfPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf {
 294     <BuildOptions>
 295       GCC:*_*_*_CC_FLAGS             = -UMDEPKG_NDEBUG
 296   }
 297   MdeModulePkg/Universal/BdsDxe/BdsDxe.inf {
 298     <BuildOptions>
 299       GCC:*_*_*_CC_FLAGS             = -UMDEPKG_NDEBUG
 300   }
 301
 302 === UEFI Windows 7 & Windows 2008 Server ===
 303
 304 * One of the '-vga std' and '-vga qxl' QEMU options should be used.
 305 * Only one video mode, 1024x768x32, is supported at OS runtime.
 306 * The '-vga qxl' QEMU option is recommended. After booting the installed
 307   guest OS, select the video card in Device Manager, and upgrade its driver
 308   to the QXL XDDM one. Download location:
 309   <http://www.spice-space.org/download.html>, Guest | Windows binaries.
 310   This enables further resolutions at OS runtime, and provides S3
 311   (suspend/resume) capability.