Re: [PATCH v1 2/3] riscv/sifive_u: Add a serial property to the sifive_u SoC

[Bin Meng]

Hi Alistair,

On Wed, Mar 4, 2020 at 9:37 AM Alistair Francis
<address@hidden> wrote:
>
> At present the board serial number is hard-coded to 1, and passed
> to OTP model during initialization. Firmware (FSBL, U-Boot) uses
> the serial number to generate a unique MAC address for the on-chip
> ethernet controller. When multiple QEMU 'sifive_u' instances are
> created and connected to the same subnet, they all have the same
> MAC address hence it creates a unusable network.
>
> A new "serial" property is introduced to the sifive_u SoC to specify
> the board serial number. When not given, the default serial number
> 1 is used.
>
> Suggested-by: Bin Meng <address@hidden>
> Signed-off-by: Alistair Francis <address@hidden>
> ---
>  hw/riscv/sifive_u.c         | 8 +++++++-
>  include/hw/riscv/sifive_u.h | 2 ++
>  2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 9a0145b5b4..e52f9d0bd4 100644
> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -488,7 +488,7 @@ static void riscv_sifive_u_soc_init(Object *obj)
>                            TYPE_SIFIVE_U_PRCI);
>      sysbus_init_child_obj(obj, "otp", &s->otp, sizeof(s->otp),
>                            TYPE_SIFIVE_U_OTP);
> -    qdev_prop_set_uint32(DEVICE(&s->otp), "serial", OTP_SERIAL);
> +    qdev_prop_set_uint32(DEVICE(&s->otp), "serial", s->serial);
>      sysbus_init_child_obj(obj, "gem", &s->gem, sizeof(s->gem),
>                            TYPE_CADENCE_GEM);
>  }
> @@ -607,10 +607,16 @@ static void riscv_sifive_u_soc_realize(DeviceState 
> *dev, Error **errp)
>          memmap[SIFIVE_U_GEM_MGMT].base, memmap[SIFIVE_U_GEM_MGMT].size);
>  }
>
> +static Property riscv_sifive_u_soc_props[] = {
> +    DEFINE_PROP_UINT32("serial", SiFiveUSoCState, serial, OTP_SERIAL),
> +    DEFINE_PROP_END_OF_LIST()

I am not sure how adding another level of property in the SoC could
solve the 'make check' error.

> +};
> +
>  static void riscv_sifive_u_soc_class_init(ObjectClass *oc, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(oc);
>
> +    device_class_set_props(dc, riscv_sifive_u_soc_props);
>      dc->realize = riscv_sifive_u_soc_realize;
>      /* Reason: Uses serial_hds in realize function, thus can't be used twice 
> */
>      dc->user_creatable = false;
> diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
> index 82667b5746..a2baa1de5f 100644
> --- a/include/hw/riscv/sifive_u.h
> +++ b/include/hw/riscv/sifive_u.h
> @@ -42,6 +42,8 @@ typedef struct SiFiveUSoCState {
>      SiFiveUPRCIState prci;
>      SiFiveUOTPState otp;
>      CadenceGEMState gem;
> +
> +    uint32_t serial;
>  } SiFiveUSoCState;
>
>  #define TYPE_RISCV_U_MACHINE MACHINE_TYPE_NAME("sifive_u")
> --

But anyway this patch does not actually work as expected. See below:

$ ./riscv64-softmmu/qemu-system-riscv64 -M sifive_u,serial=3
-nographic -m 2G -bios opensbi_u-boot_sifive_u_64.bin

OpenSBI v0.5 (Oct 31 2019 18:38:50)
   ____                    _____ ____ _____
  / __ \                  / ____|  _ \_   _|
 | |  | |_ __   ___ _ __ | (___ | |_) || |
 | |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
 | |__| | |_) |  __/ | | |____) | |_) || |_
  \____/| .__/ \___|_| |_|_____/|____/_____|
        | |
        |_|

Platform Name          : SiFive Freedom U540
Platform HART Features : RV64ACDFIMSU
Platform Max HARTs     : 5
Current Hart           : 1
Firmware Base          : 0x80000000
Firmware Size          : 96 KB
Runtime SBI Version    : 0.2

PMP0: 0x0000000080000000-0x000000008001ffff (A)
PMP1: 0x0000000000000000-0xffffffffffffffff (A,R,W,X)


U-Boot 2019.10 (Oct 31 2019 - 18:38:33 +0800)

CPU:   rv64imafdcsu
Model: SiFive HiFive Unleashed A00
DRAM:  2 GiB
MMC:
In:    serial@10010000
Out:   serial@10010000
Err:   serial@10010000
Net:
Warning: ethernet@10090000 MAC addresses don't match:
Address in ROM is          52:54:00:12:34:56
Address in environment is  70:b3:d5:92:f0:01
eth0: ethernet@10090000
Hit any key to stop autoboot:  0


See this line:
Address in environment is  70:b3:d5:92:f0:01

It should be: 70:b3:d5:92:f0:03 since I specified serial number as 3.

Regards,
Bin