refactor(core): improve frame buffer interface

[no changelog]

core/embed/io/display/inc/io/display.h

@@ -17,8 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef TREZORHAL_XDISPLAY_H
+#pragma once
-#define TREZORHAL_XDISPLAY_H
 
 #include <trezor_types.h>
 
@@ -109,9 +108,10 @@ int display_get_orientation(void);
 typedef struct {
   // Pointer to the top-left pixel
   void *ptr;
+  // Framebuffer size in bytes
+  size_t size;
   // Stride in bytes
   size_t stride;
-
 } display_fb_info_t;
 
 // Provides pointer to the inactive (writeable) framebuffer.
@@ -163,5 +163,3 @@ void display_copy_mono1p(const gfx_bitblt_t *bb);
 const char *display_save(const char *prefix);
 void display_clear_save(void);
 #endif
-
-#endif  // TREZORHAL_XDISPLAY_H

core/embed/io/display/ltdc_dsi/display_fb.c

@@ -99,9 +99,11 @@ static uint8_t *get_fb_ptr(int16_t index) {
   }
 }
 
-bool display_get_frame_buffer(display_fb_info_t *fb_dest) {
+bool display_get_frame_buffer(display_fb_info_t *fb) {
   display_driver_t *drv = &g_display_driver;
 
+  memset(fb, 0, sizeof(display_fb_info_t));
+
   if (!drv->initialized) {
     return false;
   }
@@ -116,25 +118,14 @@ bool display_get_frame_buffer(display_fb_info_t *fb_dest) {
   int16_t fb_idx = fb_queue_peek(&drv->empty_frames);
 
   if (fb_idx < 0) {
-    fb_dest->ptr = NULL;
-    fb_dest->stride = 0;
     return false;
   }
 
-  uintptr_t addr = (uintptr_t)get_fb_ptr(fb_idx);
+  fb->addr = get_fb_ptr(fb_idx);
+  fb->stride = FRAME_BUFFER_PIXELS_PER_LINE * FB_PIXEL_SIZE;
+  fb->size = fb->stride * DISPLAY_RESY;
 
-  uint32_t fb_stride = FRAME_BUFFER_PIXELS_PER_LINE * FB_PIXEL_SIZE;
+  mpu_set_active_fb(fb->addr, fb->size);
-
-  display_fb_info_t fb = {
-      .ptr = (void *)addr,
-      .stride = fb_stride,
-  };
-
-  size_t fb_size = fb_stride * DISPLAY_RESY;
-
-  mpu_set_active_fb((void *)addr, fb_size);
-
-  memcpy(fb_dest, &fb, sizeof(display_fb_info_t));
 
   return true;
 }

core/embed/io/display/st-7789/display_fb.c

@@ -174,9 +174,9 @@ void DISPLAY_TE_INTERRUPT_HANDLER(void) {
 bool display_get_frame_buffer(display_fb_info_t *fb) {
   display_driver_t *drv = &g_display_driver;
 
+  memset(fb, 0, sizeof(display_fb_info_t));
+
   if (!drv->initialized) {
-    fb->ptr = NULL;
-    fb->stride = 0;
     return false;
   }
 
@@ -185,8 +185,9 @@ bool display_get_frame_buffer(display_fb_info_t *fb) {
 
   fb->ptr = get_fb_ptr(fb_idx);
   fb->stride = DISPLAY_RESX * sizeof(uint16_t);
+  fb->size = PHYSICAL_FRAME_BUFFER_SIZE;
   // Enable access to the frame buffer from the unprivileged code
-  mpu_set_active_fb(fb->ptr, PHYSICAL_FRAME_BUFFER_SIZE);
+  mpu_set_active_fb(fb->ptr, fb->size);
 
   return true;
 }

core/embed/io/display/stm32f429i-disc1/display_driver.c

@@ -133,12 +133,13 @@ int display_get_orientation(void) {
 bool display_get_frame_buffer(display_fb_info_t *fb) {
   display_driver_t *drv = &g_display_driver;
 
+  memset(fb, 0, sizeof(display_fb_info_t));
+
   if (!drv->initialized) {
-    fb->ptr = NULL;
-    fb->stride = 0;
     return false;
   } else {
     fb->ptr = (void *)drv->framebuf;
+    fb->size = FRAME_BUFFER_SIZE;
     fb->stride = DISPLAY_RESX * sizeof(uint16_t);
     // Enable access to the frame buffer from the unprivileged code
     mpu_set_active_fb(fb->ptr, FRAME_BUFFER_SIZE);

core/embed/io/display/unix/display_driver.c

@@ -278,18 +278,20 @@ int display_get_orientation(void) {
 bool display_get_frame_buffer(display_fb_info_t *fb) {
   display_driver_t *drv = &g_display_driver;
 
+  memset(fb, 0, sizeof(display_fb_info_t));
+
   if (!drv->initialized) {
-    fb->ptr = NULL;
-    fb->stride = 0;
     return false;
   }
 
 #ifdef DISPLAY_MONO
   fb->ptr = drv->mono_framebuf;
   fb->stride = DISPLAY_RESX;
+  fb->size = DISPLAY_RESX * DISPLAY_RESY;
 #else
   fb->ptr = drv->buffer->pixels;
   fb->stride = DISPLAY_RESX * PIXEL_SIZE;
+  fb->size = DISPLAY_RESX * DISPLAY_RESY * PIXEL_SIZE;
 #endif
   return true;
 }

core/embed/io/display/vg-2864/display_driver.c

@@ -391,15 +391,16 @@ int display_get_orientation(void) {
 bool display_get_frame_buffer(display_fb_info_t *fb) {
   display_driver_t *drv = &g_display_driver;
 
+  memset(fb, 0, sizeof(display_fb_info_t));
+
   if (!drv->initialized) {
-    fb->ptr = NULL;
-    fb->stride = 0;
     return false;
   } else {
     fb->ptr = &drv->framebuf[0];
+    fb->size = FRAME_BUFFER_SIZE;
     fb->stride = DISPLAY_RESX;
     // Enable access to the frame buffer from the unprivileged code
-    mpu_set_active_fb(fb->ptr, FRAME_BUFFER_SIZE);
+    mpu_set_active_fb(fb->ptr, fb->size);
     return true;
   }
 }

core/embed/rust/src/trezorhal/display.rs

@@ -31,6 +31,7 @@ pub fn refresh() {
 pub fn get_frame_buffer() -> Option<(&'static mut [u8], usize)> {
     let mut fb_info = ffi::display_fb_info_t {
         ptr: ptr::null_mut(),
+        size: 0,
         stride: 0,
     };
 
@@ -40,12 +41,7 @@ pub fn get_frame_buffer() -> Option<(&'static mut [u8], usize)> {
         return None;
     }
 
-    let fb = unsafe {
+    let fb = unsafe { core::slice::from_raw_parts_mut(fb_info.ptr as *mut u8, fb_info.size) };
-        core::slice::from_raw_parts_mut(
-            fb_info.ptr as *mut u8,
-            DISPLAY_RESY as usize * fb_info.stride,
-        )
-    };
 
     Some((fb, fb_info.stride))
 }