https://git.reactos.org/?p=reactos.git;a=commitdiff;h=8f04a09e748ce5c9f3e5779d5964aeffa8979eda
commit 8f04a09e748ce5c9f3e5779d5964aeffa8979eda Author: Hermès Bélusca-Maïto <[email protected]> AuthorDate: Sun Jun 23 03:03:40 2019 +0200 Commit: Hermès Bélusca-Maïto <[email protected]> CommitDate: Sun Jun 23 03:07:19 2019 +0200 [BOOTVID] Fixes for VgaIsPresent() and VidInitialize(). - VgaIsPresent(): Re-select the memory mode register before playing around with the sequencer flag. Otherwise the VGA may not be detected correctly from time to time. - VidInitialize(): Simplify the initialization loop, reset AddressSpace to its "default" value of 1 when calling HalFindBusAddressTranslation() on 'NullAddress'. --- drivers/base/bootvid/i386/bootvid.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) diff --git a/drivers/base/bootvid/i386/bootvid.c b/drivers/base/bootvid/i386/bootvid.c index 2909b6c4a93..89fc4f4a6ee 100644 --- a/drivers/base/bootvid/i386/bootvid.c +++ b/drivers/base/bootvid/i386/bootvid.c @@ -332,6 +332,9 @@ VgaIsPresent(VOID) /* Write null plane */ __outpw(0x3C4, 0x100); + /* Select memory mode register */ + __outpb(0x3C4, 4); + /* Write sequencer flag */ __outpb(0x3C5, SeqReg2 ^ 8); @@ -365,24 +368,25 @@ VidInitialize(IN BOOLEAN SetMode) ULONG_PTR Context = 0; PHYSICAL_ADDRESS TranslatedAddress; PHYSICAL_ADDRESS NullAddress = {{0, 0}}, VgaAddress; - ULONG AddressSpace = 1; + ULONG AddressSpace; BOOLEAN Result; ULONG_PTR Base; /* Make sure that we have a bus translation function */ if (!HalFindBusAddressTranslation) return FALSE; - /* Get the VGA Register address */ - Result = HalFindBusAddressTranslation(NullAddress, - &AddressSpace, - &TranslatedAddress, - &Context, - TRUE); - if (!Result) return FALSE; - /* Loop trying to find possible VGA base addresses */ while (TRUE) { + /* Get the VGA Register address */ + AddressSpace = 1; + Result = HalFindBusAddressTranslation(NullAddress, + &AddressSpace, + &TranslatedAddress, + &Context, + TRUE); + if (!Result) return FALSE; + /* See if this is I/O Space, which we need to map */ if (!AddressSpace) { @@ -409,20 +413,14 @@ VidInitialize(IN BOOLEAN SetMode) &Context, FALSE); if (Result) break; - - /* Try to see if there's any other address */ - Result = HalFindBusAddressTranslation(NullAddress, - &AddressSpace, - &TranslatedAddress, - &Context, - TRUE); - if (!Result) return FALSE; } else { /* It's not, so unmap the I/O space if we mapped it */ if (!AddressSpace) MmUnmapIoSpace((PVOID)VgaRegisterBase, 0x400); } + + /* Continue trying to see if there's any other address */ } /* Success! See if this is I/O Space, which we need to map */
