Re: [PATCH 08/21] hw/arm/fsl-imx8mp: Add USDHC storage controllers

[Bernhard Beschow]

Am 21. Januar 2025 02:52:58 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Mon, 20 Jan 2025, Bernhard Beschow wrote:
>> The USDHC emulation allows for running real-world images such as those 
>> generated
>> by Buildroot. Convert the board documentation accordingly instead of running 
>> a
>> Linux kernel with ephemeral storage.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>> docs/system/arm/imx8mp-evk.rst | 39 +++++++++++++++++++++++-----------
>> include/hw/arm/fsl-imx8mp.h    |  7 ++++++
>> hw/arm/fsl-imx8mp.c            | 28 ++++++++++++++++++++++++
>> hw/arm/imx8mp-evk.c            | 18 ++++++++++++++++
>> hw/arm/Kconfig                 |  1 +
>> 5 files changed, 81 insertions(+), 12 deletions(-)
>> 
>> diff --git a/docs/system/arm/imx8mp-evk.rst b/docs/system/arm/imx8mp-evk.rst
>> index d7d08cc198..1514bc5864 100644
>> --- a/docs/system/arm/imx8mp-evk.rst
>> +++ b/docs/system/arm/imx8mp-evk.rst
>> @@ -13,6 +13,7 @@ The ``imx8mp-evk`` machine implements the following 
>> devices:
>>  * Up to 4 Cortex-A53 Cores
>>  * Generic Interrupt Controller (GICv3)
>>  * 4 UARTs
>> + * 3 USDHC Storage Controllers
>>  * Secure Non-Volatile Storage (SNVS) including an RTC
>>  * Clock Tree
>> 
>> @@ -25,25 +26,39 @@ for loading a Linux kernel.
>> Direct Linux Kernel Boot
>> ''''''''''''''''''''''''
>> 
>> -Linux mainline v6.12 release is tested at the time of writing. To build a 
>> Linux
>> -mainline kernel that can be booted by the ``imx8mp-evk`` machine, simply
>> -configure the kernel using the defconfig configuration:
>> +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
>> +of writing and involves three steps. First run the following command in the
>> +toplevel directory of the Buildroot source tree:
>> 
>> .. code-block:: bash
>> 
>> -  $ export ARCH=arm64
>> -  $ export CROSS_COMPILE=aarch64-linux-gnu-
>> -  $ make defconfig
>> +  $ make freescale_imx8mpevk_defconfig
>>   $ make
>
>Adding documentation that is removed a few patches later seems unnecessary. 
>Maybe you could keep the bare kernel docs as that could also be useful or not 
>add it in the first place? But if this is already written keeping it may make 
>more sense than dropping it.

I'd like the documentation to be complete and easy to follow at the same time. 
Buildroot achieves both, and allows for generating a cpio initrd instead. So 
I'd start with that which just requires minor adjustments here.

Best regards,
Bernhard

>
>Regards,
>BALATON Zoltan
>
>> 
>> -To boot the newly built Linux kernel in QEMU with the ``imx8mp-evk`` 
>> machine,
>> -run:
>> +Once finished successfully there is an ``output/image`` subfolder. Navigate 
>> into
>> +it and resize the SD card image to a power of two:
>> +
>> +.. code-block:: bash
>> +
>> +  $ 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 newly built image can be run in the QEMU
>> +``imx8mp-evk`` machine:
>> 
>> .. code-block:: bash
>> 
>>   $ qemu-system-aarch64 -M imx8mp-evk -smp 4 -m 3G \
>>       -display none -serial null -serial stdio \
>> -      -kernel arch/arm64/boot/Image \
>> -      -dtb arch/arm64/boot/dts/freescale/imx8mp-evk.dtb \
>> -      -initrd /path/to/rootfs.ext4 \
>> -      -append "root=/dev/ram"
>> +      -kernel Image \
>> +      -dtb imx8mp-evk-patched.dtb \
>> +      -append "root=/dev/mmcblk2p2" \
>> +      -drive file=sdcard.img,if=sd,bus=2,format=raw,id=mmcblk2
>> diff --git a/include/hw/arm/fsl-imx8mp.h b/include/hw/arm/fsl-imx8mp.h
>> index 9d2a757c2a..9832c05e8c 100644
>> --- a/include/hw/arm/fsl-imx8mp.h
>> +++ b/include/hw/arm/fsl-imx8mp.h
>> @@ -14,6 +14,7 @@
>> #include "hw/intc/arm_gicv3_common.h"
>> #include "hw/misc/imx7_snvs.h"
>> #include "hw/misc/imx8mp_ccm.h"
>> +#include "hw/sd/sdhci.h"
>> #include "qom/object.h"
>> #include "qemu/units.h"
>> 
>> @@ -27,6 +28,7 @@ enum FslImx8mpConfiguration {
>>     FSL_IMX8MP_NUM_CPUS         = 4,
>>     FSL_IMX8MP_NUM_IRQS         = 160,
>>     FSL_IMX8MP_NUM_UARTS        = 4,
>> +    FSL_IMX8MP_NUM_USDHCS       = 3,
>> };
>> 
>> struct FslImx8mpState {
>> @@ -38,6 +40,7 @@ struct FslImx8mpState {
>>     IMX8MPAnalogState  analog;
>>     IMX7SNVSState      snvs;
>>     IMXSerialState     uart[FSL_IMX8MP_NUM_UARTS];
>> +    SDHCIState         usdhc[FSL_IMX8MP_NUM_USDHCS];
>> };
>> 
>> enum FslImx8mpMemoryRegions {
>> @@ -183,6 +186,10 @@ enum FslImx8mpMemoryRegions {
>> };
>> 
>> enum FslImx8mpIrqs {
>> +    FSL_IMX8MP_USDHC1_IRQ   = 22,
>> +    FSL_IMX8MP_USDHC2_IRQ   = 23,
>> +    FSL_IMX8MP_USDHC3_IRQ   = 24,
>> +
>>     FSL_IMX8MP_UART1_IRQ    = 26,
>>     FSL_IMX8MP_UART2_IRQ    = 27,
>>     FSL_IMX8MP_UART3_IRQ    = 28,
>> diff --git a/hw/arm/fsl-imx8mp.c b/hw/arm/fsl-imx8mp.c
>> index 0abde2b1fc..612ea7bf93 100644
>> --- a/hw/arm/fsl-imx8mp.c
>> +++ b/hw/arm/fsl-imx8mp.c
>> @@ -210,6 +210,11 @@ static void fsl_imx8mp_init(Object *obj)
>>         snprintf(name, NAME_SIZE, "uart%d", i + 1);
>>         object_initialize_child(obj, name, &s->uart[i], TYPE_IMX_SERIAL);
>>     }
>> +
>> +    for (i = 0; i < FSL_IMX8MP_NUM_USDHCS; i++) {
>> +        snprintf(name, NAME_SIZE, "usdhc%d", i + 1);
>> +        object_initialize_child(obj, name, &s->usdhc[i], TYPE_IMX_USDHC);
>> +    }
>> }
>> 
>> static void fsl_imx8mp_realize(DeviceState *dev, Error **errp)
>> @@ -350,6 +355,28 @@ static void fsl_imx8mp_realize(DeviceState *dev, Error 
>> **errp)
>>                            qdev_get_gpio_in(gicdev, serial_table[i].irq));
>>     }
>> 
>> +    /* USDHCs */
>> +    for (i = 0; i < FSL_IMX8MP_NUM_USDHCS; i++) {
>> +        static const struct {
>> +            hwaddr addr;
>> +            unsigned int irq;
>> +        } usdhc_table[FSL_IMX8MP_NUM_USDHCS] = {
>> +            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC1].addr, 
>> FSL_IMX8MP_USDHC1_IRQ },
>> +            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC2].addr, 
>> FSL_IMX8MP_USDHC2_IRQ },
>> +            { fsl_imx8mp_memmap[FSL_IMX8MP_USDHC3].addr, 
>> FSL_IMX8MP_USDHC3_IRQ },
>> +        };
>> +
>> +        object_property_set_uint(OBJECT(&s->usdhc[i]), "vendor",
>> +                                 SDHCI_VENDOR_IMX, &error_abort);
>> +        if (!sysbus_realize(SYS_BUS_DEVICE(&s->usdhc[i]), errp)) {
>> +            return;
>> +        }
>> +
>> +        sysbus_mmio_map(SYS_BUS_DEVICE(&s->usdhc[i]), 0, 
>> usdhc_table[i].addr);
>> +        sysbus_connect_irq(SYS_BUS_DEVICE(&s->usdhc[i]), 0,
>> +                           qdev_get_gpio_in(gicdev, usdhc_table[i].irq));
>> +    }
>> +
>>     /* SNVS */
>>     if (!sysbus_realize(SYS_BUS_DEVICE(&s->snvs), errp)) {
>>         return;
>> @@ -367,6 +394,7 @@ static void fsl_imx8mp_realize(DeviceState *dev, Error 
>> **errp)
>>         case FSL_IMX8MP_RAM:
>>         case FSL_IMX8MP_SNVS_HP:
>>         case FSL_IMX8MP_UART1 ... FSL_IMX8MP_UART4:
>> +        case FSL_IMX8MP_USDHC1 ... FSL_IMX8MP_USDHC3:
>>             /* device implemented and treated above */
>>             break;
>> 
>> diff --git a/hw/arm/imx8mp-evk.c b/hw/arm/imx8mp-evk.c
>> index 2756d4c21c..27d9e9e8ee 100644
>> --- a/hw/arm/imx8mp-evk.c
>> +++ b/hw/arm/imx8mp-evk.c
>> @@ -11,6 +11,7 @@
>> #include "hw/arm/boot.h"
>> #include "hw/arm/fsl-imx8mp.h"
>> #include "hw/boards.h"
>> +#include "hw/qdev-properties.h"
>> #include "system/qtest.h"
>> #include "qemu/error-report.h"
>> #include "qapi/error.h"
>> @@ -40,6 +41,23 @@ static void imx8mp_evk_init(MachineState *machine)
>>     memory_region_add_subregion(get_system_memory(), FSL_IMX8MP_RAM_START,
>>                                 machine->ram);
>> 
>> +    for (int i = 0; i < FSL_IMX8MP_NUM_USDHCS; i++) {
>> +        BusState *bus;
>> +        DeviceState *carddev;
>> +        BlockBackend *blk;
>> +        DriveInfo *di = drive_get(IF_SD, i, 0);
>> +
>> +        if (!di) {
>> +            continue;
>> +        }
>> +
>> +        blk = blk_by_legacy_dinfo(di);
>> +        bus = qdev_get_child_bus(DEVICE(&s->usdhc[i]), "sd-bus");
>> +        carddev = qdev_new(TYPE_SD_CARD);
>> +        qdev_prop_set_drive_err(carddev, "drive", blk, &error_fatal);
>> +        qdev_realize_and_unref(carddev, bus, &error_fatal);
>> +    }
>> +
>>     if (!qtest_enabled()) {
>>         arm_load_kernel(&s->cpu[0], machine, &boot_info);
>>     }
>> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
>> index adb4ed8076..f880c03d35 100644
>> --- a/hw/arm/Kconfig
>> +++ b/hw/arm/Kconfig
>> @@ -582,6 +582,7 @@ config FSL_IMX8MP
>>     imply TEST_DEVICES
>>     select ARM_GIC
>>     select IMX
>> +    select SDHCI
>>     select UNIMP
>> 
>> config FSL_IMX8MP_EVK
>>