On Thu, 1 Jun 2023 at 10:22, Oliver Steffen <[email protected]> wrote: > > Quoting Gerd Hoffmann (2023-06-01 08:08:03) > > Flash can be write-protected in qemu (which is usually the case for > > code). In case the variable store flash block is configured read-only > > ovmf wouldn't be able to store EFI variables there, so not setting up > > fvb in that case (and fallhack to emulation) is the better option. > > I like the term "fallhack", I'll keep that in mind for future use >,< >
+1 Merged as #4461 > > It'll avoid problems later due to flash writes failing. > > > > The patch tries to write back the original value read earlier, so flash > > content doesn't change in case the write succeeds. But the status we > > read back after the attempt to write will tell us whenever flash is > > writable or not. > > > > Signed-off-by: Gerd Hoffmann <[email protected]> > > --- > > OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c | 14 +++++++++++--- > > 1 file changed, 11 insertions(+), 3 deletions(-) > > > > diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c > > b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c > > index 54f859de9ff9..a577aea55614 100644 > > --- a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c > > +++ b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c > > @@ -114,9 +114,17 @@ QemuFlashDetected ( > > DEBUG ((DEBUG_INFO, "QemuFlashDetected => FD behaves as RAM\n")); > > *Ptr = OriginalUint8; > > } else if (ProbeUint8 == CLEARED_ARRAY_STATUS) { > > - DEBUG ((DEBUG_INFO, "QemuFlashDetected => FD behaves as FLASH\n")); > > - FlashDetected = TRUE; > > - *Ptr = READ_ARRAY_CMD; > > + *Ptr = WRITE_BYTE_CMD; > > + *Ptr = OriginalUint8; > > + *Ptr = READ_STATUS_CMD; > > + ProbeUint8 = *Ptr; > > + *Ptr = READ_ARRAY_CMD; > > + if (ProbeUint8 & 0x10 /* programming error */) { > > + DEBUG ((DEBUG_INFO, "QemuFlashDetected => FD behaves as FLASH, > > write-protected\n")); > > + } else { > > + DEBUG ((DEBUG_INFO, "QemuFlashDetected => FD behaves as FLASH, > > writable\n")); > > + FlashDetected = TRUE; > > + } > > } > > } > > > > -- > > 2.40.1 > > > > - Oliver > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#105545): https://edk2.groups.io/g/devel/message/105545 Mute This Topic: https://groups.io/mt/99258444/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
