heads/patches/kexec-2.0.26.patch

diff --git a/Makefile.in b/Makefile.in
index 09bbd5c..500ad35 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -167,12 +167,12 @@ include $(srcdir)/kexec/Makefile
 
 # vmcore-dmesg (read dmesg from a vmcore)
 #
-include $(srcdir)/vmcore-dmesg/Makefile
+#include $(srcdir)/vmcore-dmesg/Makefile
 
 #
 # kexec_test (test program)
 #
-include $(srcdir)/kexec_test/Makefile
+#include $(srcdir)/kexec_test/Makefile
 
 SPEC=$(PACKAGE_NAME).spec
 GENERATED_SRCS:= $(SPEC)
diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
index 14263b0..55291d6 100644
--- a/kexec/arch/i386/x86-linux-setup.c
+++ b/kexec/arch/i386/x86-linux-setup.c
@@ -138,31 +138,76 @@ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
 	if (-1 == fd)
 		return -1;
 
-	if (-1 == ioctl(fd, FBIOGET_FSCREENINFO, &fix))
+	if (-1 == ioctl(fd, FBIOGET_FSCREENINFO, &fix)) {
+                dbgprintf("%s: FBIOGET_FSCREENINFO failed, can't provide framebuffer\n",
+                    __func__);
 		goto out;
-	if (-1 == ioctl(fd, FBIOGET_VSCREENINFO, &var))
+        }
+	if (-1 == ioctl(fd, FBIOGET_VSCREENINFO, &var)) {
+                dbgprintf("%s: FBIOGET_FSCREENINFO failed, can't provide framebuffer\n",
+                    __func__);
 		goto out;
-	if (0 == strcmp(fix.id, "VESA VGA")) {
+        }
+        /*
+         * If we can get a framebuffer from the host kernel, provide it to the
+         * target kernel.  This does not work for all drivers - we have to be
+         * able to get the framebuffer address, and the framebuffer must be a
+         * plain flat framebuffer.  This should work for VESA framebuffers
+         * since that is the only type of framebuffer it creates.
+         *
+         * Since Linux 4.20, getting the framebuffer address requires
+         * CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM and
+         * drm_kms_helper.drm_leak_fbdev_smem=1 on the command line.
+         *
+         * Since Linux 5.8, i915 often uses a compressed framebuffer, this must
+         * be disabled with i915.enable_fbc=0 on the kernel command line.
+         *
+         * This does not work with ast ("astdrmfb") currently as it uses a
+         * shadow buffer internally in the kernel, and there is no way to get
+         * the real framebuffer address.
+         */
+	if (0 == strcmp(fix.id, "VESA VGA")
+            || 0 == strcmp(fix.id, "inteldrmfb")
+            || 0 == strcmp(fix.id, "i915drmfb")) {
 		/* VIDEO_TYPE_VLFB */
 		real_mode->orig_video_isVGA = 0x23;
+                dbgprintf("%s: Found driver %s, providing VIDEO_TYPE_VLFB\n",
+                    __func__, fix.id);
 	} else if (0 == strcmp(fix.id, "EFI VGA")) {
 		/* VIDEO_TYPE_EFI */
 		real_mode->orig_video_isVGA = 0x70;
+                dbgprintf("%s: Found driver %s, providing VIDEO_TYPE_EFI\n",
+                    __func__, fix.id);
 	} else if (arch_options.reuse_video_type) {
 		int err;
 		off_t offset = offsetof(typeof(*real_mode), orig_video_isVGA);
 
 		/* blindly try old boot time video type */
 		err = get_bootparam(&real_mode->orig_video_isVGA, offset, 1);
-		if (err)
+		if (err) {
+                        dbgprintf("%s: Can't get booted video type, can't provide framebuffer\n",
+                            __func__);
 			goto out;
+                }
+                dbgprintf("%s: Reusing video type %d\n",
+                    __func__, real_mode->orig_video_isVGA);
 	} else {
+                fprintf(stderr, "Unknown driver %s, can't provide framebuffer\n kexec'ed OS will take over console only if %s is provided\n",
+                    fix.id, fix.id);
 		real_mode->orig_video_isVGA = 0;
 		close(fd);
 		return 0;
 	}
 	close(fd);
 
+        if (!fix.smem_start) {
+            dbgprintf("%s: Kernel did not provide framebuffer address\n",
+                __func__);
+            dbgprintf("%s: Try enabling CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM and "
+                "drm_kms_helper.drm_leak_fbdev_smem in kernel command-line options\n",
+                __func__);
+        }
+
 	real_mode->lfb_width      = var.xres;
 	real_mode->lfb_height     = var.yres;
 	real_mode->lfb_depth      = var.bits_per_pixel;
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 0e92d96..f7984a8 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -807,6 +807,27 @@ static int my_load(const char *type, int fileind, int argc, char **argv,
 	if (sort_segments(&info) < 0) {
 		return -1;
 	}
+
+#if 1
+	// force segment 0 to have memsz == bufsz
+	// so that it won't overwrite EBDA
+	if (info.segment[0].mem == 0)
+	{
+		if (kexec_debug)
+			printf("hack ebda into segment 0!\n");
+
+		uint8_t * ebda = calloc(1, info.segment[0].memsz);
+		memcpy(ebda, info.segment[0].buf, info.segment[0].bufsz);
+		info.segment[0].bufsz = info.segment[0].memsz;
+		info.segment[0].buf = ebda;
+
+		// install some default EBDA values that are off scale,
+		// which will force Xen to use the multiboot info
+		*(uint16_t*)(ebda + 0x40e) = 0xFFFF; // segment
+		*(uint16_t*)(ebda + 0x413) = 0xFFFF; // size
+	}
+#endif
+
 	/* if purgatory is loaded update it */
 	update_purgatory(&info);
 	if (entry)
diff --git a/purgatory/Makefile b/purgatory/Makefile
index 4d2d071..ee5c642 100644
--- a/purgatory/Makefile
+++ b/purgatory/Makefile
@@ -45,7 +45,6 @@ purgatory/sha256.o: $(srcdir)/util_lib/sha256.c
 	mkdir -p $(@D)
 	$(COMPILE.c) -o $@ $^
 
-$(PURGATORY): CC=$(TARGET_CC)
 $(PURGATORY): CFLAGS=$(PURGATORY_EXTRA_CFLAGS) \
 		      $($(ARCH)_PURGATORY_EXTRA_CFLAGS) \
 		      -Os -fno-builtin -ffreestanding \
diff --git a/util/Makefile b/util/Makefile
index 948ee63..833a897 100644
--- a/util/Makefile
+++ b/util/Makefile
@@ -2,7 +2,7 @@ BIN_TO_HEX:= bin/bin-to-hex
 
 $(BIN_TO_HEX): $(srcdir)/util/bin-to-hex.c
 	@$(MKDIR) -p $(@D)
-	$(LINK.o) $(CFLAGS) -o $@ $^
+	$(BUILD_CC) $(BUILD_CFLAGS) -o $@ $^
 
 $(BIN_TO_HEX): CC=$(BUILD_CC)
 $(BIN_TO_HEX): CFLAGS=$(BUILD_CFLAGS)