From: "pet...@infradead.org" <pet...@infradead.org> 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 --port=0x40a0 --speed=115200" GRUB_TERMINAL="serial console" Documentation is added to note that serial devices found on the PCI bus will be exposed as "pci,XX:XX.X" and how to find serial terminal logical names. Also, some minor documentation improvements were added. This can be tested in QEMU by adding a pci-serial device, eg. using the option "-device pci-serial". Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Tested-by: Glenn Washburn <developm...@efficientek.com> Signed-off-by: Glenn Washburn <developm...@efficientek.com> --- docs/grub.texi | 13 ++++-- grub-core/Makefile.core.def | 1 + grub-core/term/pci/serial.c | 91 +++++++++++++++++++++++++++++++++++++ grub-core/term/serial.c | 6 ++- include/grub/pci.h | 5 ++ include/grub/serial.h | 4 ++ 6 files changed, 116 insertions(+), 4 deletions(-) create mode 100644 grub-core/term/pci/serial.c diff --git a/docs/grub.texi b/docs/grub.texi index a3e9ce2d1ac7..477919ee901b 100644 --- a/docs/grub.texi +++ b/docs/grub.texi @@ -2716,8 +2716,7 @@ grub> @kbd{terminal_input serial; terminal_output serial} The command @command{serial} initializes the serial unit 0 with the speed 9600bps. The serial unit 0 is usually called @samp{COM1}, so, if you want to use COM2, you must specify @samp{--unit=1} instead. This -command accepts many other options, so please refer to @ref{serial}, -for more details. +command accepts many other options, @pxref{serial} for more details. Without argument or with @samp{--port=auto}, GRUB will attempt to use ACPI when available to auto-detect the default serial port and its @@ -4186,6 +4185,9 @@ Additionally, an MMIO address can be suffixed with: @samp{.q} for 64-bit long long word access @end itemize +Also, @var{port} can be of the form @samp{pci,XX:XX.X} to indicate a serial +device exposed on the PCI bus. + @var{speed} is the transmission speed; default is 9600. @var{word} and @var{stop} are the number of data bits and stop bits. Data bits must be in the range 5-8 and stop bits must be 1 or 2. Default is 8 data @@ -4201,10 +4203,15 @@ 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}). +Note, valid @var{port} values, excluding IO port addresses, can be found +by listing terminals with @command{terminal_output}, selecting all names +prefixed by @samp{serial_} and removing that prefix. + Examples: @example -serial --port=3f8 --speed=9600 +serial --port=0x3f8 --speed=9600 serial --port=mmio,fefb0000.l --speed=115200 +serial --port=pci,00:16.3 --speed=115200 @end example See also @ref{Serial terminal}. diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def index 801df7c21de6..fb4cc066c526 100644 --- a/grub-core/Makefile.core.def +++ b/grub-core/Makefile.core.def @@ -2064,6 +2064,7 @@ module = { ieee1275 = term/ieee1275/serial.c; mips_arc = term/arc/serial.c; efi = term/efi/serial.c; + x86 = term/pci/serial.c; enable = terminfomodule; enable = ieee1275; diff --git a/grub-core/term/pci/serial.c b/grub-core/term/pci/serial.c new file mode 100644 index 000000000000..0b8fe815f5ca --- /dev/null +++ b/grub-core/term/pci/serial.c @@ -0,0 +1,91 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2023 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 compattible 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); +} diff --git a/grub-core/term/serial.c b/grub-core/term/serial.c index c65ffc63cecb..05db4cf177c2 100644 --- a/grub-core/term/serial.c +++ b/grub-core/term/serial.c @@ -255,7 +255,8 @@ grub_cmd_serial (grub_extcmd_context_t ctxt, int argc, char **args) if (state[OPTION_PORT].set) { - if (grub_strncmp (state[OPTION_PORT].arg, "mmio,", sizeof ("mmio,") - 1) == 0) + if (grub_strncmp (state[OPTION_PORT].arg, "mmio,", sizeof ("mmio,") - 1) == 0 || + grub_strncmp (state[OPTION_PORT].arg, "pci,", sizeof ("pci,") - 1) == 0) grub_snprintf (pname, sizeof (pname), "%s", state[1].arg); else grub_snprintf (pname, sizeof (pname), "port%lx", @@ -505,6 +506,9 @@ GRUB_MOD_INIT(serial) #ifdef GRUB_MACHINE_ARC grub_arcserial_init (); #endif +#ifdef GRUB_HAS_PCI + grub_pciserial_init (); +#endif } GRUB_MOD_FINI(serial) diff --git a/include/grub/pci.h b/include/grub/pci.h index 262c89b748bb..b228bb1b71fd 100644 --- a/include/grub/pci.h +++ b/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 diff --git a/include/grub/serial.h b/include/grub/serial.h index a955c076d892..9226d51f5831 100644 --- a/include/grub/serial.h +++ b/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); -- 2.34.1 _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel