Best explained by the comment in the code:
/* Newer versions of qemu (from around 2009/12) changed the
* behaviour of monitors so that an implicit '-monitor stdio' is
* assumed if we are in -nographic mode and there is no other
* -monitor option. Only a single stdio device is allowed, so
* this broke the '-serial stdio' option. There is a new flag
* called -nodefaults which gets rid of all this default crud, so
* let's use that to avoid this and any future surprises.
*/
*/
g->cmdline[0] = g->qemu;
*/
g->cmdline[0] = g->qemu;
- snprintf (buf, sizeof buf, "%d", g->memsize);
- add_cmdline (g, "-m");
- add_cmdline (g, buf);
+ /* Newer versions of qemu (from around 2009/12) changed the
+ * behaviour of monitors so that an implicit '-monitor stdio' is
+ * assumed if we are in -nographic mode and there is no other
+ * -monitor option. Only a single stdio device is allowed, so
+ * this broke the '-serial stdio' option. There is a new flag
+ * called -nodefaults which gets rid of all this default crud, so
+ * let's use that to avoid this and any future surprises.
+ */
+ if (qemu_supports (g, "-nodefaults"))
+ add_cmdline (g, "-nodefaults");
- add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
add_cmdline (g, "-nographic");
add_cmdline (g, "-serial");
add_cmdline (g, "stdio");
add_cmdline (g, "-nographic");
add_cmdline (g, "-serial");
add_cmdline (g, "stdio");
+ snprintf (buf, sizeof buf, "%d", g->memsize);
+ add_cmdline (g, "-m");
+ add_cmdline (g, buf);
+
+ /* Force exit instead of reboot on panic */
+ add_cmdline (g, "-no-reboot");
+
/* These options recommended by KVM developers to improve reliability. */
if (qemu_supports (g, "-no-hpet"))
add_cmdline (g, "-no-hpet");
/* These options recommended by KVM developers to improve reliability. */
if (qemu_supports (g, "-no-hpet"))
add_cmdline (g, "-no-hpet");