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

[Alistair Francis]

On Wed, Oct 21, 2020 at 10:34 PM Anup Patel <anup.patel@wdc.com> wrote:
>
> Extend virt machine to allow passing custom DTB using "-dtb"
> command-line parameter. This will help users pass modified DTB
> to virt machine.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>

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

Alistair

> ---
>  hw/riscv/virt.c | 27 ++++++++++++++++++++-------
>  1 file changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 41bd2f38ba..d535119e37 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -181,6 +181,7 @@ static void create_fdt(RISCVVirtState *s, const struct 
> MemmapEntry *memmap,
>  {
>      void *fdt;
>      int i, cpu, socket;
> +    const char *dtb_filename;
>      MachineState *mc = MACHINE(s);
>      uint64_t addr, size;
>      uint32_t *clint_cells, *plic_cells;
> @@ -194,10 +195,20 @@ static void create_fdt(RISCVVirtState *s, const struct 
> MemmapEntry *memmap,
>      hwaddr flashsize = virt_memmap[VIRT_FLASH].size / 2;
>      hwaddr flashbase = virt_memmap[VIRT_FLASH].base;
>
> -    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", "riscv-virtio,qemu");
> @@ -418,9 +429,6 @@ static void create_fdt(RISCVVirtState *s, const struct 
> MemmapEntry *memmap,
>
>      qemu_fdt_add_subnode(fdt, "/chosen");
>      qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", name);
> -    if (cmdline) {
> -        qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
> -    }
>      g_free(name);
>
>      name = g_strdup_printf("/soc/rtc@%lx", (long)memmap[VIRT_RTC].base);
> @@ -441,6 +449,11 @@ static void create_fdt(RISCVVirtState *s, const struct 
> MemmapEntry *memmap,
>                                   2, flashbase + flashsize, 2, flashsize);
>      qemu_fdt_setprop_cell(s->fdt, name, "bank-width", 4);
>      g_free(name);
> +
> +update_bootargs:
> +    if (cmdline) {
> +        qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
> +    }
>  }
>
>  static inline DeviceState *gpex_pcie_init(MemoryRegion *sys_mem,
> --
> 2.25.1
>
>