grub2: avoid switching modes

to reduce flickering during boot

Issue #2778

repos/base-nova/src/core/platform.cc

@@ -490,11 +490,17 @@ Platform::Platform() :
 
 	Hip::Mem_desc *boot_fb = nullptr;
 
+	bool efi_boot = false;
+
 	/*
 	 * All "available" ram must be added to our physical allocator before all
 	 * non "available" regions that overlaps with ram get removed.
 	 */
 	for (unsigned i = 0; i < num_mem_desc; i++, mem_desc++) {
+		/* 32/64bit EFI image handle pointer - see multiboot spec 2 */
+		if (mem_desc->type == 20 || mem_desc->type == 19)
+			efi_boot = true;
+
 		if (mem_desc->type == Hip::Mem_desc::FRAMEBUFFER)
 			boot_fb = mem_desc;
 		if (mem_desc->type != Hip::Mem_desc::AVAILABLE_MEMORY) continue;
@@ -675,6 +681,9 @@ Platform::Platform() :
 				if (!boot_fb)
 					return;
 
+				if (!efi_boot)
+					return;
+
 				xml.node("framebuffer", [&] () {
 					xml.attribute("phys",   String<32>(Hex(boot_fb->addr)));
 					xml.attribute("width",  Resolution::Width::get(boot_fb->size));

repos/base/ports/grub2.hash

@@ -1 +1 @@
-e1b6f0ea55b716ef8548fbf416ec503a5d31a09d
+8cf62c015199b37018676d8c13be026989724a4b

repos/base/ports/grub2.port

@@ -3,7 +3,7 @@ VERSION   := git
 DOWNLOADS := g2fg.git
 
 URL(g2fg) := https://github.com/alex-ab/g2fg.git
-REV(g2fg) := cf35a6e5dc35a9b1961f66cd37cb1d4c23309832
+REV(g2fg) := 1b148c6479f2c1f96fa1a1ae66c8cd3bbae538f2
 DIR(g2fg) := boot
 
 default: $(DOWNLOADS)

tool/run/boot_dir/nova

@@ -107,8 +107,8 @@ proc run_boot_dir {binaries} {
 		# puts $fh "loadfont /boot/grub/unicode.pf2"
 		puts $fh "set timeout=0"
 
-		# tell grub2 to prefer 32bit framebuffer resolution
-		puts $fh "set gfxpayload=\"0x0x32\""
+		# choose best graphic mode
+		puts $fh "set gfxpayload=auto"
 
 		if {[have_include image/uefi]} {
 			puts $fh "insmod gfxterm"