Hi Ard, I believe you are referring to MdeModulePkg\Library\BaseSerialPortLib16550\BaseSerialPortLib16550.inf I have tried using this Serial Port Library. However, this has a dependency on PciLib which is difficult to resolve as we use the Serial port early in the boot. Please do let me know if you know a workaround to solve this issue.
Regards, Sami Mujawar -----Original Message----- From: Ard Biesheuvel <[email protected]> Sent: 12 October 2018 03:50 PM To: Sami Mujawar <[email protected]> Cc: [email protected]; Leif Lindholm <[email protected]>; Ruiyu Ni <[email protected]>; Evan Lloyd <[email protected]>; Matteo Carlini <[email protected]>; Stephanie Hughes-Fitt <[email protected]>; nd <[email protected]> Subject: Re: [PATCH v1 1/6] PcAtChipsetPkg: Add MMIO Support to SerialIo Lib On 12 October 2018 at 16:40, Sami Mujawar <[email protected]> wrote: > Some virtual machine managers like kvmtool emulate the PC AT Serial > Port UART in the MMIO space so that architectures that do not support > I/O Mapped I/O can use the UART. > > This patch adds MMIO support to the PC AT SerialPortLib. > > PcdSerialUseMmio is used to select I/O or MMIO support. > If PcdSerialUseMmio is > TRUE - The value is read/written from MMIO space. > FALSE - The value is read/written from I/O space. > The Default is I/O space. > IIUC kvmtool exposes a 8250, and our 8250 driver already implements support for MMIO mapped registers. Can't you use that instead? > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Sami Mujawar <[email protected]> > --- > The changes can be seen at > https://github.com/samimujawar/edk2/commit/84f908387d2031def5d374759e7 > ad4cf90786c91 > > Notes: > v1: > - Add support to read/write from UART registers using MMIO access > [SAMI] > > PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf | 4 + > PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c | 98 > ++++++++++++++++---- > 2 files changed, 84 insertions(+), 18 deletions(-) > > diff --git a/PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf > b/PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf > index > 959d6e27c9812d201d44d9249070ab7758cbfe00..d0689793040fd930701b02dae51f > f59ea16a10c4 100644 > --- a/PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf > +++ b/PcAtChipsetPkg/Library/SerialIoLib/SerialIoLib.inf > @@ -2,6 +2,7 @@ > # Library instance for SerialIo library class > # > # Copyright (c) 2006 - 2014, Intel Corporation. All rights > reserved.<BR> > +# Copyright (c) 2018, ARM Limited. All rights reserved.<BR> > # This program and the accompanying materials # are licensed and > made available under the terms and conditions of the BSD License # > which accompanies this distribution. The full text of the license may > be found at @@ -23,6 +24,7 @@ [Defines] > > [Packages] > MdePkg/MdePkg.dec > + MdeModulePkg/MdeModulePkg.dec > > [LibraryClasses] > BaseLib > @@ -31,3 +33,5 @@ [LibraryClasses] > [Sources] > SerialPortLib.c > > +[FixedPcd] > + gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio ## CONSUMES > diff --git a/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c > b/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c > index > d1a1c6a03facad09e781b5605e22a24e5f51c618..898e5f957aae998624189c6b5389 > 12da0439dfe8 100644 > --- a/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c > +++ b/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c > @@ -2,6 +2,8 @@ > UART Serial Port library functions > > Copyright (c) 2006 - 2018, Intel Corporation. All rights > reserved.<BR> > + Copyright (c) 2018, ARM Limited. All rights reserved.<BR> > + > This program and the accompanying materials > are licensed and made available under the terms and conditions of the BSD > License > which accompanies this distribution. The full text of the license may be > found at > @@ -57,6 +59,66 @@ UINT8 gParity = 0; > UINT8 gBreakSet = 0; > > /** > + Reads an 8-bit value from the serial port. > + > + This function checks PcdSerialUseMmio to determine if I/O mapped > + IO or Memory Mapped IO operations must be performed on the serial > + port. It then uses the appropriate interface to read the Value from > + the serial port. > + > + If PcdSerialUseMmio is TRUE, then the value is read from MMIO space. > + If PcdSerialUseMmio is FALSE, then the value is read from I/O space. > + > + @param Address The UART register to read from. > + > + @return The value read from the serial port. > + > +**/ > +STATIC > +UINT8 > +SerialPortRead8 ( > + IN UINTN Address > +) > +{ > + if (FixedPcdGetBool (PcdSerialUseMmio)) { > + return MmioRead8 (Address); > + } > + > + return IoRead8 (Address); > +} > + > +/** > + Writes an 8-bit value to the serial port. > + > + This function checks PcdSerialUseMmio to determine if I/O mapped > + IO or Memory Mapped IO operations must be performed on the serial > + port. It then uses the appropriate interface to write the Value to > + the serial port. > + > + If PcdSerialUseMmio is TRUE, then the value is written to MMIO space. > + If PcdSerialUseMmio is FALSE, then the value is written to I/O space. > + > + @param Address The UART register to write. > + @param Value The value to write to the I/O port. > + > + @return The value written to the serial port. > + > +**/ > +STATIC > +UINT8 > +SerialPortWrite8 ( > + IN UINTN Address, > + IN UINT8 Value > +) > +{ > + if (FixedPcdGetBool (PcdSerialUseMmio)) { > + return MmioWrite8 (Address, Value); > + } > + > + return IoWrite8 (Address, Value); > +} > + > +/** > Initialize the serial device hardware. > > If no initialization is required, then return RETURN_SUCCESS. > @@ -91,19 +153,19 @@ SerialPortInitialize ( > // Set communications format > // > OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (gParity << > 3) | (gStop << 2) | Data); > - IoWrite8 (gUartBase + LCR_OFFSET, OutputData); > + SerialPortWrite8 (gUartBase + LCR_OFFSET, OutputData); > > // > // Configure baud rate > // > - IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8)); > - IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff)); > + SerialPortWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> > + 8)); > + SerialPortWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & > + 0xff)); > > // > // Switch back to bank 0 > // > OutputData = (UINT8) ( (gBreakSet << 6) | (gParity << 3) | (gStop > << 2) | Data); > - IoWrite8 (gUartBase + LCR_OFFSET, OutputData); > + SerialPortWrite8 (gUartBase + LCR_OFFSET, OutputData); > > return RETURN_SUCCESS; > } > @@ -148,9 +210,9 @@ SerialPortWrite ( > // Wait for the serail port to be ready. > // > do { > - Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET); > + Data = SerialPortRead8 ((UINT16) gUartBase + LSR_OFFSET); > } while ((Data & LSR_TXRDY) == 0); > - IoWrite8 ((UINT16) gUartBase, *Buffer++); > + SerialPortWrite8 ((UINT16) gUartBase, *Buffer++); > } > > return Result; > @@ -189,10 +251,10 @@ SerialPortRead ( > // Wait for the serail port to be ready. > // > do { > - Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET); > + Data = SerialPortRead8 ((UINT16) gUartBase + LSR_OFFSET); > } while ((Data & LSR_RXDA) == 0); > > - *Buffer++ = IoRead8 ((UINT16) gUartBase); > + *Buffer++ = SerialPortRead8 ((UINT16) gUartBase); > } > > return Result; > @@ -220,7 +282,7 @@ SerialPortPoll ( > // > // Read the serial port status. > // > - Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET); > + Data = SerialPortRead8 ((UINT16) gUartBase + LSR_OFFSET); > > return (BOOLEAN) ((Data & LSR_RXDA) != 0); } @@ -253,7 +315,7 @@ > SerialPortSetControl ( > // > // Read the Modem Control Register. > // > - Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET); > + Mcr = SerialPortRead8 ((UINT16) gUartBase + MCR_OFFSET); > Mcr &= (~(MCR_DTRC | MCR_RTS)); > > if ((Control & EFI_SERIAL_DATA_TERMINAL_READY) == > EFI_SERIAL_DATA_TERMINAL_READY) { @@ -267,7 +329,7 @@ SerialPortSetControl ( > // > // Write the Modem Control Register. > // > - IoWrite8 ((UINT16) gUartBase + MCR_OFFSET, Mcr); > + SerialPortWrite8 ((UINT16) gUartBase + MCR_OFFSET, Mcr); > > return RETURN_SUCCESS; > } > @@ -297,7 +359,7 @@ SerialPortGetControl ( > // > // Read the Modem Status Register. > // > - Msr = IoRead8 ((UINT16) gUartBase + MSR_OFFSET); > + Msr = SerialPortRead8 ((UINT16) gUartBase + MSR_OFFSET); > > if ((Msr & MSR_CTS) == MSR_CTS) { > *Control |= EFI_SERIAL_CLEAR_TO_SEND; @@ -318,7 +380,7 @@ > SerialPortGetControl ( > // > // Read the Modem Control Register. > // > - Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET); > + Mcr = SerialPortRead8 ((UINT16) gUartBase + MCR_OFFSET); > > if ((Mcr & MCR_DTRC) == MCR_DTRC) { > *Control |= EFI_SERIAL_DATA_TERMINAL_READY; @@ -331,7 +393,7 @@ > SerialPortGetControl ( > // > // Read the Line Status Register. > // > - Lsr = IoRead8 ((UINT16) gUartBase + LSR_OFFSET); > + Lsr = SerialPortRead8 ((UINT16) gUartBase + LSR_OFFSET); > > if ((Lsr & LSR_TXRDY) == LSR_TXRDY) { > *Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY; @@ -470,19 +532,19 @@ > SerialPortSetAttributes ( > // Set communications format > // > OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (LcrParity > << 3) | (LcrStop << 2) | LcrData); > - IoWrite8 (gUartBase + LCR_OFFSET, OutputData); > + SerialPortWrite8 (gUartBase + LCR_OFFSET, OutputData); > > // > // Configure baud rate > // > - IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8)); > - IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff)); > + SerialPortWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> > + 8)); > + SerialPortWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & > + 0xff)); > > // > // Switch back to bank 0 > // > OutputData = (UINT8) ((gBreakSet << 6) | (LcrParity << 3) | > (LcrStop << 2) | LcrData); > - IoWrite8 (gUartBase + LCR_OFFSET, OutputData); > + SerialPortWrite8 (gUartBase + LCR_OFFSET, OutputData); > > return RETURN_SUCCESS; > } > -- > 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)' > > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
