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| author | Jordan Justen <jordan.l.justen@intel.com> | 2013-11-12 18:34:28 +0000 |
|---|---|---|
| committer | jljusten <jljusten@6f19259b-4bc3-4df7-8a09-765794883524> | 2013-11-12 18:34:28 +0000 |
| commit | e58e5bcd23badac8ef91d3bcc73baac3ca27e2ae (patch) | |
| tree | 680fc97e3cacbe3364bb33b40a59571f5f72c9e5 /OvmfPkg/README | |
| parent | 9a08997862989794460d53402c577ee74c60a278 (diff) | |
| download | edk2-e58e5bcd23badac8ef91d3bcc73baac3ca27e2ae.tar.gz edk2-e58e5bcd23badac8ef91d3bcc73baac3ca27e2ae.tar.bz2 edk2-e58e5bcd23badac8ef91d3bcc73baac3ca27e2ae.zip | |
OvmfPkg/README: Add information about OVMF flash layout
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14836 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'OvmfPkg/README')
| -rw-r--r-- | OvmfPkg/README | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/OvmfPkg/README b/OvmfPkg/README index 213d8648d6..f2c2fc7996 100644 --- a/OvmfPkg/README +++ b/OvmfPkg/README @@ -179,6 +179,43 @@ longer.) VirtioNetDxe | x
Intel PROEFI | x
+=== OVMF Flash Layout ===
+
+Like all current IA32/X64 system designs, OVMF's firmware
+device (rom/flash) appears in QEMU's physical address space
+just below 4GB (0x100000000).
+
+The layout of the firmware device in memory looks like:
+
++--------------------------------------- 4GB (0x100000000)
+| VTF0 (16-bit reset code) and OVMF SEC
+| (SECFV)
++--------------------------------------- varies based on flash size
+|
+| Compressed main firmware image
+| (FVMAIN_COMPACT)
+|
++--------------------------------------- base + 0x20000
+| Fault-tolerant write (FTW)
+| Spare blocks (64KB/0x10000)
++--------------------------------------- base + 0x10000
+| FTW Work block (4KB/0x1000)
++--------------------------------------- base + 0x0f000
+| Event log area (4KB/0x1000)
++--------------------------------------- base + 0x0e000
+| Non-volatile variable storage
+| area (56KB/0xe000)
++--------------------------------------- base address
+
+OVMF supports building a 1MB or a 2MB flash image. The base address for
+a 1MB image in QEMU physical memory is 0xfff00000. The base address for
+a 2MB image is 0xffe00000.
+
+The code in SECFV locates FVMAIN_COMPACT, and decompresses the
+main firmware (MAINFV) into RAM memory at address 0x800000. The
+remaining OVMF firmware then uses this decompressed firmware
+volume image.
+
=== UNIXGCC Debug ===
If you build with the UNIXGCC toolchain, then debugging will be disabled
|