Re: [PATCH for-7.2 v2 17/20] device_tree.c: support remaining FDT prop types

[David Gibson]

On Fri, Aug 05, 2022 at 06:39:45AM -0300, Daniel Henrique Barboza wrote:
> When printing a blob with 'dtc' using the '-O dts' option there are 3
> distinct data types being printed: strings, arrays of uint32s and
> regular byte arrays.
> 
> Previous patch added support to print strings. Let's add the remaining
> formats. We want to resemble the format that 'dtc -O dts' uses, so every
> uint32 array uses angle brackets (<>), and regular byte array uses square
> brackets ([]). For properties that has no values we keep printing just
> its name.
> 
> The /chosen FDT node from the pSeris machine gives an example of all
> property types 'info fdt' is now able to display:
> 
> (qemu) info fdt /chosen
> chosen {
>     ibm,architecture-vec-5 = [0 0]
>     rng-seed = <0x5967a270 0x62b0fb4f 0x8262b46a 0xabf48423 0xcce9615 
> 0xf9daae64 0x66564790 0x357d1604>
>     ibm,arch-vec-5-platform-support = <0x178018c0 0x19001a40>
>     linux,pci-probe-only = <0x0>
>     stdout-path = '/vdevice/vty@71000000'
>     linux,stdout-path = '/vdevice/vty@71000000'
>     qemu,graphic-depth = <0x20>
>     qemu,graphic-height = <0x258>
>     qemu,graphic-width = <0x320>
> }
> 
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>  softmmu/device_tree.c | 58 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 57 insertions(+), 1 deletion(-)
> 
> diff --git a/softmmu/device_tree.c b/softmmu/device_tree.c
> index 8691c3ccc0..9d95e4120b 100644
> --- a/softmmu/device_tree.c
> +++ b/softmmu/device_tree.c
> @@ -681,6 +681,53 @@ static bool fdt_prop_is_string(const void *data, int 
> size)
>      return true;
>  }
>  
> +static bool fdt_prop_is_uint32_array(int size)
> +{
> +    return size % 4 == 0;
> +}
> +
> +static void fdt_prop_format_uint32_array(GString *buf,
> +                                         const char *propname,
> +                                         const void *data,
> +                                         int prop_size, int padding)
> +{
> +    const fdt32_t *array = data;
> +    int array_len = prop_size / 4;
> +    int i;
> +
> +    g_string_append_printf(buf, "%*s%s = <", padding, "", propname);
> +
> +    for (i = 0; i < array_len; i++) {
> +        g_string_append_printf(buf, "0x%" PRIx32, fdt32_to_cpu(array[i]));
> +
> +        if (i < array_len - 1) {
> +            g_string_append_printf(buf, " ");
> +        }
> +    }
> +
> +    g_string_append_printf(buf, ">\n");

Add a ';' to match dts.

> +}
> +
> +static void fdt_prop_format_val(GString *buf, const char *propname,
> +                                const void *data, int prop_size,
> +                                int padding)
> +{
> +    const char *val = data;
> +    int i;
> +
> +    g_string_append_printf(buf, "%*s%s = [", padding, "", propname);
> +
> +    for (i = 0; i < prop_size; i++) {
> +        g_string_append_printf(buf, "%x", val[i]);

For dts like output you need %02x.  In [] notation, the spaces are
actually optional and ignored, so [0 0] is equivalent to [00], which is
equivalent to "".

> +
> +        if (i < prop_size - 1) {
> +            g_string_append_printf(buf, " ");
> +        }
> +    }
> +
> +    g_string_append_printf(buf, "]\n");

;

> +}
> +
>  static void fdt_format_node(GString *buf, int node, int depth)
>  {
>      const struct fdt_property *prop = NULL;
> @@ -699,11 +746,20 @@ static void fdt_format_node(GString *buf, int node, int 
> depth)
>          prop = fdt_get_property_by_offset(fdt, property, &prop_size);
>          propname = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
>  
> +        if (prop_size == 0) {
> +            g_string_append_printf(buf, "%*s%s;\n", padding, "", propname);
> +            continue;
> +        }
> +
>          if (fdt_prop_is_string(prop->data, prop_size)) {
>              g_string_append_printf(buf, "%*s%s = '%s'\n",
>                                     padding, "", propname, prop->data);
> +        } else if (fdt_prop_is_uint32_array(prop_size)) {
> +            fdt_prop_format_uint32_array(buf, propname, prop->data, 
> prop_size,
> +                                         padding);
>          } else {
> -            g_string_append_printf(buf, "%*s%s;\n", padding, "", propname);
> +            fdt_prop_format_val(buf, propname, prop->data,
> +                                prop_size, padding);
>          }
>      }
>  

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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