Merge tag 'kgdb-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux (f1e45535) · Commits · 戴 / test

Documentation/admin-guide/kernel-parameters.txt

+20 −0

Original line number	Diff line number	Diff line
		@@ -1190,6 +1190,11 @@
		This is designed to be used in conjunction with
		the boot argument: earlyprintk=vga

		This parameter works in place of the kgdboc parameter
		but can only be used if the backing tty is available
		very early in the boot process. For early debugging
		via a serial port see kgdboc_earlycon instead.

		edd= [EDD]
		Format: {"off" \| "on" \| "skip[mbr]"}

		@@ -2112,6 +2117,21 @@
		kms, kbd format: kms,kbd
		kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]

		kgdboc_earlycon= [KGDB,HW]
		If the boot console provides the ability to read
		characters and can work in polling mode, you can use
		this parameter to tell kgdb to use it as a backend
		until the normal console is registered. Intended to
		be used together with the kgdboc parameter which
		specifies the normal console to transition to.

		The name of the early console should be specified
		as the value of this parameter. Note that the name of
		the early console might be different than the tty
		name passed to kgdboc. It's OK to leave the value
		blank and the first boot console that implements
		read() will be picked.

		kgdbwait [KGDB] Stop kernel execution and enter the
		kernel debugger at the earliest opportunity.

+24 −0

Original line number	Diff line number	Diff line
		@@ -274,6 +274,30 @@ don't like this are to hack gdb to send the :kbd:`SysRq-G` for you as well as
		on the initial connect, or to use a debugger proxy that allows an
		unmodified gdb to do the debugging.

		Kernel parameter: ``kgdboc_earlycon``
		-------------------------------------

		If you specify the kernel parameter ``kgdboc_earlycon`` and your serial
		driver registers a boot console that supports polling (doesn't need
		interrupts and implements a nonblocking read() function) kgdb will attempt
		to work using the boot console until it can transition to the regular
		tty driver specified by the ``kgdboc`` parameter.

		Normally there is only one boot console (especially that implements the
		read() function) so just adding ``kgdboc_earlycon`` on its own is
		sufficient to make this work. If you have more than one boot console you
		can add the boot console's name to differentiate. Note that names that
		are registered through the boot console layer and the tty layer are not
		the same for the same port.

		For instance, on one board to be explicit you might do::

		kgdboc_earlycon=qcom_geni kgdboc=ttyMSM0

		If the only boot console on the device was "qcom_geni", you could simplify::

		kgdboc_earlycon kgdboc=ttyMSM0

		Kernel parameter: ``kgdbwait``
		------------------------------

+1 −0

Original line number	Diff line number	Diff line
		@@ -60,6 +60,7 @@ config X86
		select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
		select ARCH_HAS_DEBUG_VIRTUAL
		select ARCH_HAS_DEVMEM_IS_ALLOWED
		select ARCH_HAS_EARLY_DEBUG if KGDB
		select ARCH_HAS_ELF_RANDOMIZE
		select ARCH_HAS_FAST_MULTIPLIER
		select ARCH_HAS_FILTER_PGPROT

+23 −0

Original line number	Diff line number	Diff line
		@@ -109,6 +109,28 @@ static void early_serial8250_write(struct console *console,
		uart_console_write(port, s, count, serial_putc);
		}

		#ifdef CONFIG_CONSOLE_POLL
		static int early_serial8250_read(struct console *console,
		char *s, unsigned int count)
		{
		struct earlycon_device *device = console->data;
		struct uart_port *port = &device->port;
		unsigned int status;
		int num_read = 0;

		while (num_read < count) {
		status = serial8250_early_in(port, UART_LSR);
		if (!(status & UART_LSR_DR))
		break;
		s[num_read++] = serial8250_early_in(port, UART_RX);
		}

		return num_read;
		}
		#else
		#define early_serial8250_read NULL
		#endif

		static void __init init_port(struct earlycon_device *device)
		{
		struct uart_port *port = &device->port;
		@@ -149,6 +171,7 @@ int __init early_serial8250_setup(struct earlycon_device *device,
		init_port(device);

		device->con->write = early_serial8250_write;
		device->con->read = early_serial8250_read;
		return 0;
		}
		EARLYCON_DECLARE(uart8250, early_serial8250_setup);

+32 −0

Original line number	Diff line number	Diff line
		@@ -2435,6 +2435,37 @@ static void pl011_early_write(struct console con, const char s, unsigned n)
		uart_console_write(&dev->port, s, n, pl011_putc);
		}

		#ifdef CONFIG_CONSOLE_POLL
		static int pl011_getc(struct uart_port *port)
		{
		if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE)
		return NO_POLL_CHAR;

		if (port->iotype == UPIO_MEM32)
		return readl(port->membase + UART01x_DR);
		else
		return readb(port->membase + UART01x_DR);
		}

		static int pl011_early_read(struct console con, char s, unsigned int n)
		{
		struct earlycon_device *dev = con->data;
		int ch, num_read = 0;

		while (num_read < n) {
		ch = pl011_getc(&dev->port);
		if (ch == NO_POLL_CHAR)
		break;

		s[num_read++] = ch;
		}

		return num_read;
		}
		#else
		#define pl011_early_read NULL
		#endif

		/*
		* On non-ACPI systems, earlycon is enabled by specifying
		* "earlycon=pl011,<address>" on the kernel command line.
		@@ -2454,6 +2485,7 @@ static int __init pl011_early_console_setup(struct earlycon_device *device,
		return -ENODEV;

		device->con->write = pl011_early_write;
		device->con->read = pl011_early_read;

		return 0;
		}