From: Ani Sinha <anisinha@redhat.com>
Date: Fri, 19 Jul 2024 13:49:37 +0000 (+0530)
Subject: hw/x86: add a couple of comments explaining how the kernel image is parsed
X-Git-Tag: qemu-xen-4.20.0~6^2~2
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=80e3541282af347538a37ee0673bcc04c622ad1c;p=qemu-xen.git

hw/x86: add a couple of comments explaining how the kernel image is parsed

Cosmetic: add comments in x86_load_linux() pointing to the kernel documentation
so that users can better understand the code.

CC: qemu-trivial@nongnu.org
Signed-off-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---

diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index c0c66a0eb5..992ea1f25e 100644
--- a/hw/i386/x86-common.c
+++ b/hw/i386/x86-common.c
@@ -665,8 +665,11 @@ void x86_load_linux(X86MachineState *x86ms,
         exit(1);
     }
 
-    /* kernel protocol version */
-    if (ldl_p(header + 0x202) == 0x53726448) {
+    /*
+     * kernel protocol version.
+     * Please see https://www.kernel.org/doc/Documentation/x86/boot.txt
+     */
+    if (ldl_p(header + 0x202) == 0x53726448) /* Magic signature "HdrS" */ {
         protocol = lduw_p(header + 0x206);
     } else {
         /*