fix(ui/fonts): make font kernings optional.

diff --git a/core/embed/rust/src/ui/display/font.rs b/core/embed/rust/src/ui/display/font.rs
index 76c8b01d..d0e17076 100644
--- a/core/embed/rust/src/ui/display/font.rs
+++ b/core/embed/rust/src/ui/display/font.rs
@@ -21,7 +21,7 @@ pub struct FontInfo {
     pub baseline: i16,
     pub glyph_data: &'static [&'static [u8]],
     pub glyph_nonprintable: &'static [u8],
-    pub kernings: &'static [(u8, u8, i8)],
+    pub kernings: Option<&'static [(u8, u8, i8)]>,
 }
 /// Convenience type for font references defined in the `fonts` module.
 pub type Font = &'static FontInfo;
@@ -263,9 +263,11 @@ impl FontInfo {
     pub fn get_kerning(&self, left_ch: char, right_ch: char) -> i8 {
         let left: u8 = left_ch as u8;
         let right = right_ch as u8;
-        for &(l, r, v) in self.kernings {
-            if l == left && r == right {
-                return v;
+        if let Some(kernings) = self.kernings {
+            for &(l, r, v) in kernings {
+                if l == left && r == right {
+                    return v;
+                }
             }
         }
         0
diff --git a/core/tools/codegen/gen_font.mako b/core/tools/codegen/gen_font.mako
index 3aa911ab..0ba5603e 100644
--- a/core/tools/codegen/gen_font.mako
+++ b/core/tools/codegen/gen_font.mako
@@ -33,7 +33,7 @@ const Font_${name}_upper: [&[u8]; ${len(glyph_array_upper)}] = [
 % endfor
 ];
 % endif
-% if gen_normal:
+% if gen_kernings:
 
 /// Array of kerning tripples
 const Font_${name}_kernings: [(u8, u8, i8); ${len(kernings)}] = [
@@ -44,7 +44,6 @@ const Font_${name}_kernings: [(u8, u8, i8); ${len(kernings)}] = [
 % endif
 % if gen_normal:
 
-
 /// FontInfo struct for normal ASCII usage
 pub const Font_${name}_info: FontInfo = FontInfo {
     translation_blob_idx: ${font_info["translation_blob_idx"]},
@@ -53,7 +52,11 @@ pub const Font_${name}_info: FontInfo = FontInfo {
     baseline: ${font_info["baseline"]},
     glyph_data: &${font_info["glyph_array"]},
     glyph_nonprintable: &${font_info["nonprintable"]},
-    kernings: &${font_info["kernings"]},
+%if gen_kernings:
+    kernings: &${font_info_upper["kernings"]},
+%else:
+    kernings: None,
+%endif
 };
 % endif
 % if gen_upper:
@@ -66,6 +69,10 @@ pub const Font_${name}_upper_info: FontInfo = FontInfo {
     baseline: ${font_info_upper["baseline"]},
     glyph_data: &${font_info_upper["glyph_array"]},
     glyph_nonprintable: &${font_info_upper["nonprintable"]},
+%if gen_kernings:
     kernings: &${font_info_upper["kernings"]},
+%else:
+    kernings: None,
+%endif
 };
 % endif
diff --git a/core/tools/codegen/gen_font.py b/core/tools/codegen/gen_font.py
index 4953ca00..9f4292af 100755
--- a/core/tools/codegen/gen_font.py
+++ b/core/tools/codegen/gen_font.py
@@ -248,6 +248,7 @@ class FaceProcessor:
         ext: str = "ttf",
         gen_normal: bool = True,  # generate font with all the letters
         gen_upper: bool = False,  # generate font with only upper-cased letters
+        gen_kernings: bool = False,  # generate kerning data
         font_idx: int | None = None,  # idx to UTF-8 foreign chars data
         font_idx_upper: int | None = None,  # idx to UTF-8 upper-cased foreign chars
     ) -> None:
@@ -266,6 +267,7 @@ class FaceProcessor:
         self.ext = ext
         self.gen_normal = gen_normal
         self.gen_upper = gen_upper
+        self.gen_kernings = gen_kernings
 
         self.face = freetype.Face(str(FONTS_DIR / f"{name}-{style}.{ext}"))
         self.face.set_pixel_sizes(0, size)
@@ -491,6 +493,7 @@ class FaceProcessor:
             "kernings": kernings,
             "gen_normal": self.gen_normal,
             "gen_upper": self.gen_upper,
+            "gen_kernings": self.gen_kernings,
             "font_info": font_info,
             "font_info_upper": font_info_upper,
         }