On Thu, Jan 26, 2023 at 10:37:35AM +0100, Peter Zijlstra wrote:
> On Wed, Dec 21, 2022 at 01:59:02PM +0100, Daniel Kiper wrote:
> > Sorry for late reply...
> >
> > May I ask you to send the patches using "git send-email"?
>
> I'll try -- I'm one of the few quilt holdouts in Linux-land so I don't
> have much experience with it.
>
>
> > Please add a blurb how to use this driver to the docs/grub.texi file.
> >
> > > GRUB_TERMINAL="serial console"
> > >
> > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> > > ---
> > >
> > > Index: grub/grub-core/Makefile.core.def
> > > ===================================================================
> > > --- grub.orig/grub-core/Makefile.core.def
> > > +++ grub/grub-core/Makefile.core.def
> > > @@ -2047,6 +2047,7 @@ module = {
> > > ieee1275 = term/ieee1275/serial.c;
> > > mips_arc = term/arc/serial.c;
> > > efi = term/efi/serial.c;
> > > + pci = term/pci/serial.c;
> >
> > I think this should be "x86 = term/pci/serial.c".
>
> I thought the whole purpose of Glenn's patch was to allow doing the 'pci
> =' thing, so that all platforms that support PCI get to have the
> benefit.
>
> But if you really want I can make it 'x86 =' ofcourse.
Ben, you've lived a very long time in !x86 land, can you elucidate us on
this? My thinking is that if someone sticks a 16550 on a PCI board, this
driver should work on any PCI enabled platform, not just x86, rite?
>
>
> > > +static int
> > > +find_pciserial (grub_pci_device_t dev, grub_pci_id_t pciid, void *data)
> >
> > grub_pci_id_t pciid __attribute__ ((unused))
> >
> > > +{
> > > + grub_pci_address_t cmd_addr, class_addr, bar_addr;
> > > + struct grub_serial_port *port;
> > > + grub_uint32_t class, bar;
> > > + grub_uint16_t cmdreg;
> > > + int *port_num = data;
> > > + grub_err_t err;
> > > +
> > > + (void)pciid;
> >
> > ... and please drop this...
> >
>
> > > +error:
> >
> > s/error/fail/
> >
> > And please add a space before label...
>
> All done, except the Makefile thing, find the updated version below.
> I'll attempt to git-send-email both patches once we agree on the
> Makefile hunk.
>
>
> ---
> Subject: term/serial: Add support for PCI serial devices
>
> Loosely based on early_pci_serial_init() from Linux, allow GRUB to make
> use of PCI serial devices.
>
> Specifically, my Alderlake NUC exposes the Intel AMT SoL UART as a PCI
> enumerated device but doesn't include it in the EFI tables.
>
> Tested and confirmed working on a "Lenovo P360 Tiny" with Intel AMT
> enabled. This specific machine has (from lspci -vv):
>
> 00:16.3 Serial controller: Intel Corporation Device 7aeb (rev 11) (prog-if 02
> [16550])
> DeviceName: Onboard - Other
> Subsystem: Lenovo Device 330e
> Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort-
> <TAbort- <MAbort- >SERR- <PERR- INTx-
> Interrupt: pin D routed to IRQ 19
> Region 0: I/O ports at 40a0 [size=8]
> Region 1: Memory at b4224000 (32-bit, non-prefetchable) [size=4K]
> Capabilities: [40] MSI: Enable- Count=1/1 Maskable- 64bit+
> Address: 0000000000000000 Data: 0000
> Capabilities: [50] Power Management version 3
> Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA
> PME(D0-,D1-,D2-,D3hot-,D3cold-)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Kernel driver in use: serial
>
> From which the following config (/etc/default/grub) gets a working
> serial setup:
>
> GRUB_CMDLINE_LINUX="console=tty0 earlyprintk=pciserial,00:16.3,115200
> console=ttyS0,115200"
> GRUB_SERIAL_COMMAND="serial --speed=115200 pci_00:16.3"
> GRUB_TERMINAL="serial console"
>
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> Tested-by: Glenn Washburn <developm...@efficientek.com>
> Reviewed-by: Glenn Washburn <developm...@efficientek.com>
> ---
>
> Index: grub/grub-core/Makefile.core.def
> ===================================================================
> --- grub.orig/grub-core/Makefile.core.def
> +++ grub/grub-core/Makefile.core.def
> @@ -2057,6 +2057,7 @@ module = {
> ieee1275 = term/ieee1275/serial.c;
> mips_arc = term/arc/serial.c;
> efi = term/efi/serial.c;
> + pci = term/pci/serial.c;
>
> enable = terminfomodule;
> enable = ieee1275;
> Index: grub/grub-core/term/pci/serial.c
> ===================================================================
> --- /dev/null
> +++ grub/grub-core/term/pci/serial.c
> @@ -0,0 +1,93 @@
> +/*
> + * GRUB -- GRand Unified Bootloader
> + * Copyright (C) 2022 Free Software Foundation, Inc.
> + *
> + * GRUB is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 3 of the License, or
> + * (at your option) any later version.
> + *
> + * GRUB is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <grub/serial.h>
> +#include <grub/term.h>
> +#include <grub/types.h>
> +#include <grub/pci.h>
> +#include <grub/mm.h>
> +#include <grub/misc.h>
> +
> +static int
> +find_pciserial (grub_pci_device_t dev,
> + grub_pci_id_t pciid __attribute__ ((unused)),
> + void *data __attribute__ ((unused)))
> +{
> + grub_pci_address_t cmd_addr, class_addr, bar_addr;
> + struct grub_serial_port *port;
> + grub_uint32_t class, bar;
> + grub_uint16_t cmdreg;
> + grub_err_t err;
> +
> + cmd_addr = grub_pci_make_address (dev, GRUB_PCI_REG_COMMAND);
> + cmdreg = grub_pci_read (cmd_addr);
> +
> + class_addr = grub_pci_make_address (dev, GRUB_PCI_REG_REVISION);
> + class = grub_pci_read (class_addr);
> +
> + bar_addr = grub_pci_make_address (dev, GRUB_PCI_REG_ADDRESS_REG0);
> + bar = grub_pci_read (bar_addr);
> +
> + /* 16550 compatible MODEM or SERIAL */
> + if (((class >> 16) != GRUB_PCI_CLASS_COMMUNICATION_MODEM &&
> + (class >> 16) != GRUB_PCI_CLASS_COMMUNICATION_SERIAL) ||
> + ((class >> 8) & 0xff) != GRUB_PCI_SERIAL_16550_COMPATIBLE)
> + return 0;
> +
> + if ((bar & GRUB_PCI_ADDR_SPACE_MASK) != GRUB_PCI_ADDR_SPACE_IO)
> + return 0;
> +
> + port = grub_zalloc (sizeof (*port));
> + if (port == NULL)
> + return 0;
> +
> + port->name = grub_xasprintf ("pci_%02x:%02x.%x",
> + grub_pci_get_bus (dev),
> + grub_pci_get_device (dev),
> + grub_pci_get_function (dev));
> + if (port->name == NULL)
> + goto fail;
> +
> + grub_pci_write (cmd_addr, cmdreg | GRUB_PCI_COMMAND_IO_ENABLED);
> +
> + port->driver = &grub_ns8250_driver;
> + port->port = bar & GRUB_PCI_ADDR_IO_MASK;
> + err = grub_serial_config_defaults (port);
> + if (err != GRUB_ERR_NONE)
> + {
> + grub_print_error ();
> + goto fail;
> + }
> +
> + err = grub_serial_register (port);
> + if (err != GRUB_ERR_NONE)
> + goto fail;
> +
> + return 0;
> +
> + fail:
> + grub_free (port->name);
> + grub_free (port);
> + return 0;
> +}
> +
> +void
> +grub_pciserial_init (void)
> +{
> + grub_pci_iterate (find_pciserial, NULL);
> +}
> Index: grub/grub-core/term/serial.c
> ===================================================================
> --- grub.orig/grub-core/term/serial.c
> +++ grub/grub-core/term/serial.c
> @@ -505,6 +505,9 @@ GRUB_MOD_INIT(serial)
> #ifdef GRUB_MACHINE_ARC
> grub_arcserial_init ();
> #endif
> +#ifdef GRUB_HAS_PCI
> + grub_pciserial_init ();
> +#endif
> }
>
> GRUB_MOD_FINI(serial)
> Index: grub/include/grub/pci.h
> ===================================================================
> --- grub.orig/include/grub/pci.h
> +++ grub/include/grub/pci.h
> @@ -80,8 +80,13 @@
>
> #define GRUB_PCI_STATUS_DEVSEL_TIMING_SHIFT 9
> #define GRUB_PCI_STATUS_DEVSEL_TIMING_MASK 0x0600
> +
> #define GRUB_PCI_CLASS_SUBCLASS_VGA 0x0300
> #define GRUB_PCI_CLASS_SUBCLASS_USB 0x0c03
> +#define GRUB_PCI_CLASS_COMMUNICATION_SERIAL 0x0700
> +#define GRUB_PCI_CLASS_COMMUNICATION_MODEM 0x0703
> +
> +#define GRUB_PCI_SERIAL_16550_COMPATIBLE 0x02
>
> #ifndef ASM_FILE
>
> Index: grub/include/grub/serial.h
> ===================================================================
> --- grub.orig/include/grub/serial.h
> +++ grub/include/grub/serial.h
> @@ -210,6 +210,10 @@ grub_arcserial_init (void);
> struct grub_serial_port *grub_arcserial_add_port (const char *path);
> #endif
>
> +#ifdef GRUB_HAS_PCI
> +void grub_pciserial_init (void);
> +#endif
> +
> struct grub_serial_port *grub_serial_find (const char *name);
> extern struct grub_serial_driver grub_ns8250_driver;
> void EXPORT_FUNC(grub_serial_unregister_driver) (struct grub_serial_driver
> *driver);
> Index: grub/docs/grub.texi
> ===================================================================
> --- grub.orig/docs/grub.texi
> +++ grub/docs/grub.texi
> @@ -1386,6 +1386,7 @@ separated by spaces.
> Valid terminal input names depend on the platform, but may include
> @samp{console} (native platform console), @samp{serial} (serial terminal),
> @samp{serial_<port>} (serial terminal with explicit port selection),
> +@samp{pci_<bus>:<device>.<function>} (PCI serial with explicit location),
> @samp{at_keyboard} (PC AT keyboard), or @samp{usb_keyboard} (USB keyboard
> using the HID Boot Protocol, for cases where the firmware does not handle
> this).
> @@ -1399,6 +1400,7 @@ separated by spaces.
> Valid terminal output names depend on the platform, but may include
> @samp{console} (native platform console), @samp{serial} (serial terminal),
> @samp{serial_<port>} (serial terminal with explicit port selection),
> +@samp{pci_<bus>:<device>.<function>} (PCI serial with explicit location),
> @samp{gfxterm} (graphics-mode output), @samp{vga_text} (VGA text output),
> @samp{mda_text} (MDA text output), @samp{morse} (Morse-coding using system
> beeper) or @samp{spkmodem} (simple data protocol using system speaker).
> @@ -4165,7 +4167,7 @@ Commands usable anywhere in the menu and
> @node serial
> @subsection serial
>
> -@deffn Command serial [@option{--unit=unit}] [@option{--port=port}]
> [@option{--speed=speed}] [@option{--word=word}] [@option{--parity=parity}]
> [@option{--stop=stop}]
> +@deffn Command serial [@option{--unit=unit}] [@option{--port=port}]
> [@option{--speed=speed}] [@option{--word=word}] [@option{--parity=parity}]
> [@option{--stop=stop}] [@option{name}]
> Initialize a serial device. @var{unit} is a number in the range 0-3
> specifying which serial port to use; default is 0, which corresponds to
> the port often called COM1.
> @@ -4197,6 +4199,19 @@ If passed no @var{unit} nor @var{port},
> the system default serial port and its configuration. If this information
> is not available, it will default to @var{unit} 0.
>
> +If used @var{name}, a machine and driver specific name given during probing,
> +will be used to indicate which serial port to use. Possible forms include:
> +@itemize @bullet
> +@item
> +@samp{serial_<port>} as an alternative to --port
> +@item
> +@samp{usbN} the N'th USB serial detected
> +@item
> +@samp{efiN} the N'th EFI serial detected
> +@item
> +@samp{pci_<bus>:<device>.<func>} PCI serial at the specified location
> +@end itemize
> +
> The serial port is not used as a communication channel unless the
> @command{terminal_input} or @command{terminal_output} command is used
> (@pxref{terminal_input}, @pxref{terminal_output}).
> @@ -4205,6 +4220,7 @@ Examples:
> @example
> serial --port=3f8 --speed=9600
> serial --port=mmio,fefb0000.l --speed=115200
> +serial --speed=115200 pci_00:16.3
> @end example
>
> See also @ref{Serial terminal}.
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