This flag was introduced to ignore bad firmware values. These were
present in older versions of EDK-II that many devices (both Ampere and
Amazon) used. QEMU also used this value, but fixed it. But since it's
tied to the firmware bug not the device name ID it doesn't make sense to
have it flagged there.
Sponsored by: Netflix
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D47947
If we have a new enough SPCR, then use it when it provides a
PreciseBaudrate and/or a UartClkFreq.
Sponsored by: Netflix
Reviewed by: andrew,adrian
Differential Revision: https://reviews.freebsd.org/D47097
With newer, more diverse hardware designs, the rclk can be
unknown. Currently deployed systems have no standard way to discover the
baud-clock generator frequency. However, sometimes we have a fairly good
idea that the firmware programmed the UART to be the baud rate that it's
telling us it's at. Create a way to instruct the uart class drivers to
compute the baud clock frequency the first time their init routines are
called. Usually the 'divisors' are relatively small, meaning we will
likely have a fairly large error (goes as 1 / (divisor + 1). However,
we also know that the baud-generator clock needs to be divided down
to the baud-rate +/- about 5% (so while the error could be large for
an arbitrary baud-clock, standard baud rates generally will give
an error of 5% or less).
Often, the console speed and the getty-configured speed are the same, so
this heuristic allows boot messages and login sessions to work.
Sponsored by: Netflix
Reviewed by: andrew
Differential Revision: https://reviews.freebsd.org/D47072
The Debug Port Table 2 (DBG2) contains information on which devices
can be used for debugging purposes.
Add support to the uart driver to use the DBG2 table when enabled from
loader.
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D44359
In preperation for adding debug port support add a generic function
to setup the uart from ACPI tables.
Reviewed by: imp
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D44358
Split out the common parts of building the uart devinfo from ACPI
tables from the SPCR parser. This will be used when we support the DBG2
table to find the debug uart to be used by the kernel gdb stub.
Reviewed by: imp
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D44357
Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.
Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/
Sponsored by: Netflix
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
FreeBSD detects serial ports twice: First, very early in the boot
process, in order to obtain a usable console; and second, during
the device probe/attach process. When a UART is discovered during
device probing, FreeBSD attempts to determine whether it is a
device which was already being used as a console; without this,
the console doesn't work in userland.
Unfortunately it's possible for a UART to be mapped to a different
location in memory when it is discovered on a bus than it has when
it is announced via the ACPI SPCR table; this breaks the matching
process, which relies on comparing bus addresses.
To address this, we introduce a concept of "unique" serial devices,
i.e. devices which are guaranteed to be present *only once* on any
system. If we discover one of these during device probing, we can
match it to a same-PCI-vendor-and-device-numbers console which was
announced via the ACPI SPCR table, regardless of the differing bus
addresses.
At present, the only unique serial device is the "Amazon PCI serial
device" (vendor 0x1d0f, device 0x8250) found in some EC2 instances.
This unbreaks the serial console on those systems.
Reviewed by: imp
MFC after: 3 days
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D34703
The ACPI Specification defines a Generic Address Structure (GAS),
which is used to describe UART controller register layout in the
SPCR table. The driver responsible for parsing it (uart_cpu_acpi)
wrongly associates the Access Size field to the uart_bas's regshft
and the register BitWidth to the regiowidth - according to
the definitions it should be opposite.
This problem remained hidden most likely because the majority of platforms
use 32-bit registers (BitWidth) which are accessed with the according
size (Dword). However on Marvell Armada 8k / Cn913x platforms,
the 32-bit registers should be accessed with Byte granulity, which
unveiled the issue.
This patch fixes above by proper values assignment and slightly improved
parsing.
Note that handling of the AccessWidth set to EFI_ACPI_6_0_UNDEFINED is
needed to work around a buggy SPCR table on EC2 x86 "bare metal" instances.
Reviewed by: manu, imp, cperciva, greg_unrelenting.technology
Obtained from: Semihalf
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25373
This takes the SPCR code currently in uart_cpu_arm64.c, moves it into
a new uart_cpu_acpi.c (with some associated refactoring), and uses it
from both arm64 and x86.
An SPCR serial port address AccessWidth field value of 0 ("reserved")
is now treated as 1 ("byte access") in order to work around a buggy
SPCR table on Amazon EC2 i3.metal instances.
Reviewed by: manu, Greg V
MFC after: 3 days
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D20357
