hw/openrisc: Fixed undercounting of TTCR in continuous mode

In the existing design, TTCR is prone to undercounting when running in
continuous mode. This manifests as a timer interrupt appearing to
t

hw/openrisc: Fixed undercounting of TTCR in continuous mode

In the existing design, TTCR is prone to undercounting when running in
continuous mode. This manifests as a timer interrupt appearing to
trigger a few cycles prior to the deadline set in SPR_TTMR_TP.

When the timer triggers, the virtual time delta in nanoseconds between
the time when the timer was set, and when it triggers is calculated.
This nanoseconds value is then divided by TIMER_PERIOD (50) to compute
an increment of cycles to apply to TTCR.

However, this calculation rounds down the number of cycles causing the
undercounting.

A simplistic solution would be to instead round up the number of cycles,
however this will result in the accumulation of timing error over time.

This patch corrects the issue by calculating the time delta in
nanoseconds between when the timer was last reset and the timer event.
This approach allows the TTCR value to be rounded up, but without
accumulating error over time.

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>
[stafford: Incremented version in vmstate_or1k_timer, checkpatch fixes]
Signed-off-by: Stafford Horne <shorne@gmail.com>

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hw/openrisc/openrisc_sim: keep serial@90000000 as default

We used to only have a single UART on the platform and it was located at
address 0x90000000. When the number of UARTs was increased to 4, th

hw/openrisc/openrisc_sim: keep serial@90000000 as default

We used to only have a single UART on the platform and it was located at
address 0x90000000. When the number of UARTs was increased to 4, the
first UART remained at it's location, but instead of being the first one
to be registered, it became the last.

This caused QEMU to pick 0x90000300 as the default UART, which broke
software that hardcoded the address of 0x90000000 and expected it's
output to be visible when the user configured only a single console.

This caused regressions[1] in the barebox test suite when updating to a
newer QEMU. As there seems to be no good reason to register the UARTs in
inverse order, let's register them by ascending address, so existing
software can remain oblivious to the additional UART ports.

Changing the order of uart registration alone breaks Linux which
was choosing the UART at 0x90000300 as the default for ttyS0. To fix
Linux we fix three things in the device tree:

1. Define stdout-path only one time for the first registered UART
instead of incorrectly defining for each UART.
2. Change the UART alias name from 'uart0' to 'serial0' as almost all
Linux tty drivers look for an alias starting with "serial".
3. Add the UART nodes so they appear in the final DTB in the
order starting with the lowest address and working upwards.

In summary these changes mean that the QEMU default UART (serial_hd(0))
is now setup where:

* serial_hd(0) is the lowest-address UART
* serial_hd(0) is listed first in the DTB
* serial_hd(0) is the /chosen/stdout-path one
* the /aliases/serial0 alias points at serial_hd(0)

[1]: https://lore.barebox.org/barebox/707e7c50-aad1-4459-8796-0cc54bab32e2@pengutronix.de/T/#m5da26e8a799033301489a938b5d5667b81cef6ad

Fixes: 777784bda468 ("hw/openrisc: support 4 serial ports in or1ksim")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
[stafford: Change to serial0 alias and update change message, reverse
uart registration order]
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

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hw/char: Extract serial-mm

hw/char/serial currently contains the implementation of both TYPE_SERIAL and
TYPE_SERIAL_MM. According to serial_class_init(), TYPE_SERIAL is an internal
class while TYPE_

hw/char: Extract serial-mm

hw/char/serial currently contains the implementation of both TYPE_SERIAL and
TYPE_SERIAL_MM. According to serial_class_init(), TYPE_SERIAL is an internal
class while TYPE_SERIAL_MM is used by numerous machine types directly. Let's
move the latter into its own module which makes the dependencies more obvious
and the code more tidy.

The includes and the dependencies have been converted mechanically except in the
hw/char directories which were updated manually. The result was compile-tested.
Now, only hw/char makes direct use of TYPE_SERIAL:

# grep -r -e "select SERIAL" | grep -v SERIAL_
hw/char/Kconfig: select SERIAL
hw/char/Kconfig: select SERIAL
hw/char/Kconfig: select SERIAL
hw/char/Kconfig: select SERIAL
hw/char/Kconfig: select SERIAL

# grep -r -e "/serial\\.h"
include/hw/char/serial-mm.h:#include "hw/char/serial.h"
hw/char/serial-pci-multi.c:#include "hw/char/serial.h"
hw/char/serial.c:#include "hw/char/serial.h"
hw/char/serial-isa.c:#include "hw/char/serial.h"
hw/char/serial-pci.c:#include "hw/char/serial.h"

Tested-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Link: https://lore.kernel.org/r/20240905073832.16222-4-shentey@gmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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kconfig: express dependency of individual boards on libfdt

Now that boards are enabled by default and the "CONFIG_FOO=y"
entries are gone from configs/devices/, there cannot be any more
a conflicts

kconfig: express dependency of individual boards on libfdt

Now that boards are enabled by default and the "CONFIG_FOO=y"
entries are gone from configs/devices/, there cannot be any more
a conflicts between the default contents of configs/devices/
and a failed "depends on" clause.

With this change, each individual board or target can express
whether it needs FDT. It can then include the common code in the
build via "select DEVICE_TREE", which will also as tell meson to link
with libfdt.

This allows building non-microvm x86 emulators without having
libfdt available.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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meson: pick libfdt from common_ss when building target-specific files

Avoid having to list dependencies such as libfdt twice, both on common_ss
and specific_ss. Instead, just take all the dependenc

meson: pick libfdt from common_ss when building target-specific files

Avoid having to list dependencies such as libfdt twice, both on common_ss
and specific_ss. Instead, just take all the dependencies in common_ss
and allow the target-specific libqemu-*.fa library to use them.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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openrisc: switch boards to "default y"

Some targets use "default y" for boards to filter out those that require
TCG. For consistency we are switching all other targets to do the same.
Continue with

openrisc: switch boards to "default y"

Some targets use "default y" for boards to filter out those that require
TCG. For consistency we are switching all other targets to do the same.
Continue with OpenRISC.

No changes to generated config-devices.mak file.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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