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authorGerd Hoffmann <kraxel@redhat.com>2021-12-13 09:16:56 +0100
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2021-12-13 12:16:32 +0000
commitc802f8935ca34f06f22292c92ed152db89c66f00 (patch)
treea3e7a5ee9fbecad23d809f11bb015694d8e9e319
parent79dcaf7054dbe90a30c7ce288b7f2ed882d96cf2 (diff)
downloadedk2-c802f8935ca34f06f22292c92ed152db89c66f00.zip
edk2-c802f8935ca34f06f22292c92ed152db89c66f00.tar.gz
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OvmfPkg/Microvm/fdt: add empty fdt
FdtClient is unhappy without a device tree, so add an empty fdt which we can use in case etc/fdt is not present in fw_cfg. On ARM machines a device tree is mandatory for hardware detection, that's why FdtClient fails hard. On microvm the device tree is only used to detect virtio-mmio devices (this patch series) and the pcie host (future series). So edk2 can continue with limited functionality in case no device tree is present: no storage, no network, but serial console and direct kernel boot works. qemu release 6.2 & newer will provide a device tree for microvm. Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3689 Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
-rw-r--r--OvmfPkg/PlatformPei/Platform.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c
index c9ec1d7..d0323c6 100644
--- a/OvmfPkg/PlatformPei/Platform.c
+++ b/OvmfPkg/PlatformPei/Platform.c
@@ -16,6 +16,7 @@
//
// The Library classes this module consumes
//
+#include <Library/BaseMemoryLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
@@ -321,6 +322,18 @@ PciExBarInitialization (
);
}
+static const UINT8 EmptyFdt[] = {
+ 0xd0, 0x0d, 0xfe, 0xed, 0x00, 0x00, 0x00, 0x48,
+ 0x00, 0x00, 0x00, 0x38, 0x00, 0x00, 0x00, 0x48,
+ 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00, 0x11,
+ 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x09,
+};
+
VOID
MicrovmInitialization (
VOID
@@ -335,8 +348,9 @@ MicrovmInitialization (
Status = QemuFwCfgFindFile ("etc/fdt", &FdtItem, &FdtSize);
if (EFI_ERROR (Status)) {
- DEBUG ((DEBUG_INFO, "%a: no etc/fdt found in fw_cfg\n", __FUNCTION__));
- return;
+ DEBUG ((DEBUG_INFO, "%a: no etc/fdt found in fw_cfg, using dummy\n", __FUNCTION__));
+ FdtItem = 0;
+ FdtSize = sizeof (EmptyFdt);
}
FdtPages = EFI_SIZE_TO_PAGES (FdtSize);
@@ -346,8 +360,12 @@ MicrovmInitialization (
return;
}
- QemuFwCfgSelectItem (FdtItem);
- QemuFwCfgReadBytes (FdtSize, NewBase);
+ if (FdtItem) {
+ QemuFwCfgSelectItem (FdtItem);
+ QemuFwCfgReadBytes (FdtSize, NewBase);
+ } else {
+ CopyMem (NewBase, EmptyFdt, FdtSize);
+ }
FdtHobData = BuildGuidHob (&gFdtHobGuid, sizeof (*FdtHobData));
if (FdtHobData == NULL) {