WIP (temporary): probe step checkpoints in scanout driver

drivers/video/mt8183_scanout.c

@@ -188,18 +188,21 @@ static int mt8183_scanout_probe(struct udevice *dev)
 	       (void __iomem *)MTK_GPIO_DOUT_SET(PAD_DISP_PWM));
 	writel(MTK_GPIO_DOUT_BIT(PAD_EN_LCD_BL),
 	       (void __iomem *)MTK_GPIO_DOUT_SET(PAD_EN_LCD_BL));
+	krane_diag_band(520, 20, 0x0000ff80);	/* mint: revival writes done */
 
 	/*
 	 * The coreboot table sits above the DRAM window described by the
 	 * control DTB; map it before parsing.
 	 */
 	mmu_map_region(COREBOOT_TABLE_ADDR, SZ_4K, false);
+	krane_diag_band(540, 20, 0x008000ff);	/* violet: table mapped */
 
 	ret = find_framebuffer(COREBOOT_TABLE_ADDR, &fb);
 	if (ret) {
 		krane_diag_band(800, 40, 0x00ff0000);	/* red: lbio failed */
 		return log_msg_ret("lbio", ret);
 	}
+	krane_diag_band(560, 20, 0x00ffff80);	/* pale yellow: LBIO found */
 
 	if (fb.bits_per_pixel != 32 || fb.red_pos != 16 || fb.red_size != 8 ||
 	    fb.green_pos != 8 || fb.green_size != 8 ||
@@ -207,6 +210,7 @@ static int mt8183_scanout_probe(struct udevice *dev)
 		krane_diag_band(820, 40, 0x00ff0000);	/* red: fmt mismatch */
 		return log_msg_ret("fmt", -ENOTSUPP);
 	}
+	krane_diag_band(580, 20, 0x0080ffff);	/* pale cyan: fmt OK */
 
 	/*
 	 * Use the address from the coreboot table when it is a plausible