diff --git a/kvm.c b/kvm.c
index 03becb8..9a27170 100644
--- a/kvm.c
+++ b/kvm.c
@@ -179,6 +179,7 @@ void kvm__enable_singlestep(struct kvm *self)
 #define BOOT_CMDLINE_OFFSET	0x20000
 
 #define BOOT_PROTOCOL_REQUIRED	0x202
+#define LOAD_HIGH		0x01
 
 static int load_flat_binary(struct kvm *self, int fd)
 {
@@ -257,19 +258,37 @@ static bool load_bzimage(struct kvm *self, int fd, const char *kernel_cmdline)
 	while ((nr = read(fd, p, 65536)) > 0)
 		p += nr;
 
+	p = guest_flat_to_host(self, BOOT_CMDLINE_OFFSET);
 	if (kernel_cmdline) {
 		cmdline_size = strlen(kernel_cmdline) + 1;
 		if (cmdline_size > boot.hdr.cmdline_size)
 			cmdline_size = boot.hdr.cmdline_size;
 
-		p = guest_flat_to_host(self, BOOT_CMDLINE_OFFSET);
 		memset(p, 0, boot.hdr.cmdline_size);
 		memcpy(p, kernel_cmdline, cmdline_size - 1);
-
-		p = guest_real_to_host(self, BOOT_LOADER_SELECTOR, 0x228);
-		*(uint32_t *)p = BOOT_CMDLINE_OFFSET;
 	}
 
+#define hdr_offset(member)			\
+	offsetof(struct boot_params, hdr) +	\
+	offsetof(struct setup_header, member)
+#define guest_hdr(kvm, member)			\
+	guest_real_to_host(kvm,			\
+		BOOT_LOADER_SELECTOR,		\
+		hdr_offset(member))
+
+	/* some fields in guest header have to be updated */
+	p = guest_hdr(self, cmd_line_ptr);
+	*(uint32_t *)p = BOOT_CMDLINE_OFFSET;
+
+	p = guest_hdr(self, type_of_loader);
+	*(uint8_t *)p = 0xff;
+
+	p = guest_hdr(self, heap_end_ptr);
+	*(uint16_t *)p = 0xfe00;
+
+	p = guest_hdr(self, loadflags);
+	*(uint8_t *)p |= CAN_USE_HEAP;
+
 	self->boot_selector	= BOOT_LOADER_SELECTOR;
 	/*
 	 * The real-mode setup code starts at offset 0x200 of a bzImage. See