Re: [PATCH 1/2] hw/riscv: sifive_u: Allow passing custom DTB

[Alistair Francis]

On Wed, Oct 21, 2020 at 10:33 PM Anup Patel <anup.patel@wdc.com> wrote:
>
> Extend sifive_u machine to allow passing custom DTB using "-dtb"
> command-line parameter. This will help users pass modified DTB
> or Linux SiFive DTB to sifive_u machine.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/riscv/sifive_u.c | 28 ++++++++++++++++++++--------
>  1 file changed, 20 insertions(+), 8 deletions(-)
>
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 6ad975d692..554e38abf0 100644
> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -100,14 +100,25 @@ static void create_fdt(SiFiveUState *s, const struct 
> MemmapEntry *memmap,
>      int cpu;
>      uint32_t *cells;
>      char *nodename;
> +    const char *dtb_filename;
>      char ethclk_names[] = "pclk\0hclk";
>      uint32_t plic_phandle, prci_phandle, gpio_phandle, phandle = 1;
>      uint32_t hfclk_phandle, rtcclk_phandle, phy_phandle;
>
> -    fdt = s->fdt = create_device_tree(&s->fdt_size);
> -    if (!fdt) {
> -        error_report("create_device_tree() failed");
> -        exit(1);
> +    dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
> +    if (dtb_filename) {
> +        fdt = s->fdt = load_device_tree(dtb_filename, &s->fdt_size);
> +        if (!fdt) {
> +            error_report("load_device_tree() failed");
> +            exit(1);
> +        }
> +        goto update_bootargs;
> +    } else {
> +        fdt = s->fdt = create_device_tree(&s->fdt_size);
> +        if (!fdt) {
> +            error_report("create_device_tree() failed");
> +            exit(1);
> +        }
>      }
>
>      qemu_fdt_setprop_string(fdt, "/", "model", "SiFive HiFive Unleashed 
> A00");
> @@ -390,13 +401,14 @@ static void create_fdt(SiFiveUState *s, const struct 
> MemmapEntry *memmap,
>
>      qemu_fdt_add_subnode(fdt, "/chosen");
>      qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename);
> -    if (cmdline) {
> -        qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
> -    }
> -
>      qemu_fdt_setprop_string(fdt, "/aliases", "serial0", nodename);
>
>      g_free(nodename);
> +
> +update_bootargs:
> +    if (cmdline) {
> +        qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
> +    }
>  }
>
>  static void sifive_u_machine_reset(void *opaque, int n, int level)
> --
> 2.25.1
>
>