Re: [PATCH v2 6/7] hw/arm: Allwinner A10 enable SPL load from MMC

[Strahinja Jankovic]

Hi,

On Sun, Dec 18, 2022 at 10:59 PM Philippe Mathieu-Daudé
<philmd@linaro.org> wrote:
>
> On 18/12/22 22:19, Strahinja Jankovic wrote:
> > This patch enables copying of SPL from MMC if `-kernel` parameter is not
> > passed when starting QEMU. SPL is copied to SRAM_A.
> >
> > The approach is reused from Allwinner H3 implementation.
> >
> > Tested with Armbian and custom Yocto image.
> >
> > Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
> >
> > Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
> > ---
> >   hw/arm/allwinner-a10.c         | 18 ++++++++++++++++++
> >   hw/arm/cubieboard.c            |  5 +++++
> >   include/hw/arm/allwinner-a10.h | 21 +++++++++++++++++++++
> >   3 files changed, 44 insertions(+)
> >
> > diff --git a/hw/arm/allwinner-a10.c b/hw/arm/allwinner-a10.c
> > index 17e439777e..dc1966ff7a 100644
> > --- a/hw/arm/allwinner-a10.c
> > +++ b/hw/arm/allwinner-a10.c
> > @@ -24,7 +24,9 @@
> >   #include "sysemu/sysemu.h"
> >   #include "hw/boards.h"
> >   #include "hw/usb/hcd-ohci.h"
> > +#include "hw/loader.h"
> >
> > +#define AW_A10_SRAM_A_BASE      0x00000000
> >   #define AW_A10_DRAMC_BASE       0x01c01000
> >   #define AW_A10_MMC0_BASE        0x01c0f000
> >   #define AW_A10_CCM_BASE         0x01c20000
> > @@ -38,6 +40,22 @@
> >   #define AW_A10_RTC_BASE         0x01c20d00
> >   #define AW_A10_I2C0_BASE        0x01c2ac00
> >
> > +void allwinner_a10_bootrom_setup(AwA10State *s, BlockBackend *blk)
> > +{
> > +    const int64_t rom_size = 32 * KiB;
> > +    g_autofree uint8_t *buffer = g_new0(uint8_t, rom_size);
> > +
> > +    if (blk_pread(blk, 8 * KiB, rom_size, buffer, 0) < 0) {
> > +        error_setg(&error_fatal, "%s: failed to read BlockBackend data",
> > +                   __func__);
> > +        return;
> > +    }
> > +
> > +    rom_add_blob("allwinner-a10.bootrom", buffer, rom_size,
> > +                  rom_size, AW_A10_SRAM_A_BASE,
> > +                  NULL, NULL, NULL, NULL, false);
> > +}
> > +
> >   static void aw_a10_init(Object *obj)
> >   {
> >       AwA10State *s = AW_A10(obj);
> > diff --git a/hw/arm/cubieboard.c b/hw/arm/cubieboard.c
> > index afc7980414..37659c35fd 100644
> > --- a/hw/arm/cubieboard.c
> > +++ b/hw/arm/cubieboard.c
> > @@ -99,6 +99,11 @@ static void cubieboard_init(MachineState *machine)
> >       memory_region_add_subregion(get_system_memory(), AW_A10_SDRAM_BASE,
> >                                   machine->ram);
> >
> > +    /* Load target kernel or start using BootROM */
> > +    if (!machine->kernel_filename && blk && blk_is_available(blk)) {
> > +        /* Use Boot ROM to copy data from SD card to SRAM */
> > +        allwinner_a10_bootrom_setup(a10, blk);
> > +    }
> >       /* TODO create and connect IDE devices for ide_drive_get() */
> >
> >       cubieboard_binfo.ram_size = machine->ram_size;
> > diff --git a/include/hw/arm/allwinner-a10.h b/include/hw/arm/allwinner-a10.h
> > index 763935fca9..b3c9ed24c7 100644
> > --- a/include/hw/arm/allwinner-a10.h
> > +++ b/include/hw/arm/allwinner-a10.h
> > @@ -15,6 +15,7 @@
> >   #include "hw/misc/allwinner-a10-ccm.h"
> >   #include "hw/misc/allwinner-a10-dramc.h"
> >   #include "hw/i2c/allwinner-i2c.h"
> > +#include "sysemu/block-backend.h"
> >
> >   #include "target/arm/cpu.h"
> >   #include "qom/object.h"
> > @@ -47,4 +48,24 @@ struct AwA10State {
> >       OHCISysBusState ohci[AW_A10_NUM_USB];
> >   };
> >
> > +/**
> > + * Emulate Boot ROM firmware setup functionality.
> > + *
> > + * A real Allwinner A10 SoC contains a Boot ROM
> > + * which is the first code that runs right after
> > + * the SoC is powered on. The Boot ROM is responsible
> > + * for loading user code (e.g. a bootloader) from any
> > + * of the supported external devices and writing the
> > + * downloaded code to internal SRAM. After loading the SoC
> > + * begins executing the code written to SRAM.
> > + *
> > + * This function emulates the Boot ROM by copying 32 KiB
> > + * of data
>
> "at offset 8 KiB" ?

Yes, that is correct. I will update the function description.

Best regards,
Strahinja

>
> > from the given block device and writes it to
> > + * the start of the first internal SRAM memory.
> > + *
> > + * @s: Allwinner A10 state object pointer
> > + * @blk: Block backend device object pointer
> > + */
> > +void allwinner_a10_bootrom_setup(AwA10State *s, BlockBackend *blk);
> > +
> >   #endif
>