On Fri, 8 Nov 2019 at 17:15, Alistair Francis <address@hidden> wrote:
On Fri, Nov 8, 2019 at 9:05 AM Palmer Dabbelt <address@hidden> wrote:
>
> The test finisher implements the reset command, which means it's a
> "sifive,test1" device. This is a backwards compatible change, so it's
> also a "sifive,test0" device. I copied the odd idiom for adding a
> two-string compatible field from the ARM virt board.
>
> Fixes: 9a2551ed6f ("riscv: sifive_test: Add reset functionality")
> Signed-off-by: Palmer Dabbelt <address@hidden>
> Signed-off-by: Palmer Dabbelt <address@hidden>
> ---
> hw/riscv/virt.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 23f340df19..74f2dce81c 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -359,7 +359,10 @@ static void create_fdt(RISCVVirtState *s, const struct
MemmapEntry *memmap,
> nodename = g_strdup_printf("/test@%lx",
> (long)memmap[VIRT_TEST].base);
> qemu_fdt_add_subnode(fdt, nodename);
> - qemu_fdt_setprop_string(fdt, nodename, "compatible", "sifive,test0");
> + {
> + const char compat[] = "sifive,test1\0sifive,test0";
Does this really work? Why not use qemu_fdt_setprop_cells()?
Alistair
> + qemu_fdt_setprop(fdt, nodename, "compatible", compat,
sizeof(compat));
> + }
qemu_fdt_setprop_cells() is for "set this property to
contain this list of 32-bit integers" (and it does a byteswap
of each 32-bit value from host to BE). That's not what
you want for a string (or a string list, which is what
we have here).
Cc'ing David Gibson who's our device tree expert to see if there's
a nicer way to write this. Oddly, given that it's used in the
ubiquitous 'compatible' prop, the dtc Documentation/manual.txt
doesn't say anything about properties being able to be
'string lists', only 'strings', '32 bit numbers', 'lists of
32-bit numbers' and 'byte sequences'. You have to dig through
the header file comments to deduce that a string list is
represented by a string with embedded NULs separating
each list item.