On 03/03/2016 03:59 AM, Aleksey Makarov wrote: > > > On 03/01/2016 06:31 PM, Peter Hurley wrote: >> On 02/29/2016 04:02 AM, Aleksey Makarov wrote: >>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port >>> Console Redirection Table) [2] as a mandatory ACPI table that >>> specifies the configuration of serial console. >>> >>> Introduce a new function acpi_console_check(). At the uart port >>> registration, this function checks if the ACPI SPCR table specifies >>> its argument of type struct uart_port to be a console >>> and if so calls add_preferred_console(). >> >> How will a user enable an earlycon on the same console as the SPCR >> console if there is no DBG2 table? > > ... > [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '') > [ 0.000000] bootconsole [pl11] enabled > ... > [ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000 > ... > [ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0] > [ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA > [ 0.319502] console [ttyAMA0] enabled > [ 0.319502] console [ttyAMA0] enabled > [ 0.319933] bootconsole [pl11] disabled > [ 0.319933] bootconsole [pl11] disabled > ... > > Why? That's pretty disingenuous; via command line? By that measure, none of your patches are required because a user can already start both console and earlycon without them. With the console location specified in the SPCR, earlycon should be opt-in on the command-line simply with "earlycon" command-line parameter. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
