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hw/arm/imx8mp-evk: Remove unimplemented cpu-idle-states properties from devicetree

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The cpu-idle-states property causes a hard boot hang. Rather than documenting
the workaround, perform the removal from the devicetree automatically.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
[Bernhard: split patch, update documentation, adapt commit message]
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-ID: <20250405214900.7114-3-shentey@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
This commit is contained in:
Guenter Roeck 2025-04-05 23:48:59 +02:00 committed by Philippe Mathieu-Daudé
parent 535ef19566
commit 764ca3ec89
2 changed files with 16 additions and 10 deletions
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12
docs/system/arm/imx8mp-evk.rst
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@ -35,7 +35,7 @@ Direct Linux Kernel Boot
Probably the easiest way to get started with a whole Linux system on the machine Probably the easiest way to get started with a whole Linux system on the machine
is to generate an image with Buildroot. Version 2024.11.1 is tested at the time is to generate an image with Buildroot. Version 2024.11.1 is tested at the time
of writing and involves three steps. First run the following commands in the of writing and involves two steps. First run the following commands in the
toplevel directory of the Buildroot source tree: toplevel directory of the Buildroot source tree:
.. code-block:: bash .. code-block:: bash
@ -50,14 +50,6 @@ it and resize the SD card image to a power of two:
$ qemu-img resize sdcard.img 256M $ qemu-img resize sdcard.img 256M
Finally, the device tree needs to be patched with the following commands which
will remove the ``cpu-idle-states`` properties from CPU nodes:
.. code-block:: bash
$ dtc imx8mp-evk.dtb | sed '/cpu-idle-states/d' > imx8mp-evk-patched.dts
$ dtc imx8mp-evk-patched.dts -o imx8mp-evk-patched.dtb
Now that everything is prepared the machine can be started as follows: Now that everything is prepared the machine can be started as follows:
.. code-block:: bash .. code-block:: bash
@ -65,6 +57,6 @@ Now that everything is prepared the machine can be started as follows:
$ qemu-system-aarch64 -M imx8mp-evk -smp 4 -m 3G \ $ qemu-system-aarch64 -M imx8mp-evk -smp 4 -m 3G \
-display none -serial null -serial stdio \ -display none -serial null -serial stdio \
-kernel Image \ -kernel Image \
-dtb imx8mp-evk-patched.dtb \ -dtb imx8mp-evk.dtb \
-append "root=/dev/mmcblk2p2" \ -append "root=/dev/mmcblk2p2" \
-drive file=sdcard.img,if=sd,bus=2,format=raw,id=mmcblk2 -drive file=sdcard.img,if=sd,bus=2,format=raw,id=mmcblk2

14
hw/arm/imx8mp-evk.c
View File

@ -15,6 +15,19 @@
#include "system/qtest.h" #include "system/qtest.h"
#include "qemu/error-report.h" #include "qemu/error-report.h"
#include "qapi/error.h" #include "qapi/error.h"
#include <libfdt.h>
static void imx8mp_evk_modify_dtb(const struct arm_boot_info *info, void *fdt)
{
int offset;
/* Remove cpu-idle-states property from CPU nodes */
offset = fdt_node_offset_by_compatible(fdt, -1, "arm,cortex-a53");
while (offset >= 0) {
fdt_nop_property(fdt, offset, "cpu-idle-states");
offset = fdt_node_offset_by_compatible(fdt, offset, "arm,cortex-a53");
}
}
static void imx8mp_evk_init(MachineState *machine) static void imx8mp_evk_init(MachineState *machine)
{ {
@ -32,6 +45,7 @@ static void imx8mp_evk_init(MachineState *machine)
.board_id = -1, .board_id = -1,
.ram_size = machine->ram_size, .ram_size = machine->ram_size,
.psci_conduit = QEMU_PSCI_CONDUIT_SMC, .psci_conduit = QEMU_PSCI_CONDUIT_SMC,
.modify_dtb = imx8mp_evk_modify_dtb,
}; };
s = FSL_IMX8MP(object_new(TYPE_FSL_IMX8MP)); s = FSL_IMX8MP(object_new(TYPE_FSL_IMX8MP));