Re: [Qemu-devel] [PATCH] allow bootdevice change from the monitor [v2]

[Gildas <gildas.ml@gmail.com>]

This patch allows changing the boot device from within the monitor.

For v2, remarks from Aurelien were taken in account and a small
description is added to the documentation,

Signed-off-by: Gildas Le Nadan <3ntr0p13@gmail.com>

diff -Nur -x .svn qemu/trunk/hw/pc.c b/hw/pc.c
--- qemu/trunk/hw/pc.c	2008-04-25 13:57:40.000000000 +0200
+++ b/hw/pc.c	2008-04-25 13:54:15.000000000 +0200
@@ -189,6 +189,33 @@
     return 0;
 }

+/* copy/pasted from cmos_init, should be made a general function
+ and used there as well */
+int pc_set_bootdevice(const char *boot_device)
+{
+#define PC_MAX_BOOT_DEVICES 3
+    RTCState *s = rtc_state;
+    int nbds, bds[3] = { 0, };
+    int i;
+
+    nbds = strlen(boot_device);
+    if (nbds > PC_MAX_BOOT_DEVICES) {
+        term_printf("Too many boot devices for PC\n");
+        return(1);
+    }
+    for (i = 0; i < nbds; i++) {
+        bds[i] = boot_device2nibble(boot_device[i]);
+        if (bds[i] == 0) {
+            term_printf("Invalid boot device for PC: '%c'\n",
+                    boot_device[i]);
+            return(1);
+        }
+    }
+    rtc_set_memory(s, 0x3d, (bds[1] << 4) | bds[0]);
+    rtc_set_memory(s, 0x38, (bds[2] << 4));
+    return(0);
+}
+
 /* hd_table must contain 4 block drivers */
 static void cmos_init(int ram_size, const char *boot_device,
BlockDriverState **hd_table)
 {
@@ -698,6 +725,8 @@
     BlockDriverState *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
     BlockDriverState *fd[MAX_FD];

+    set_bootdevice_fct = pc_set_bootdevice;
+
     linux_boot = (kernel_filename != NULL);

     /* init CPUs */
diff -Nur -x .svn qemu/trunk/monitor.c b/monitor.c
--- qemu/trunk/monitor.c	2008-04-25 13:57:42.000000000 +0200
+++ b/monitor.c	2008-04-25 13:55:54.000000000 +0200
@@ -1019,6 +1019,21 @@
                 suffix, addr, size * 2, val);
 }

+static void do_bootdevice_set(const char *bootdevice)
+{
+    int res;
+
+    if (set_bootdevice_fct != NULL)  {
+        res = set_bootdevice_fct(bootdevice);
+        if (res == 0)
+            term_printf("boot device list now set to %s\n", bootdevice);
+        else
+            term_printf("setting boot device list failed with error
%i\n", res);
+    } else {
+        term_printf("no function defined to set boot device list for
this architecture\n");
+    }
+}
+
 static void do_system_reset(void)
 {
     qemu_system_reset_request();
@@ -1356,6 +1371,8 @@
       "addr size file", "save to disk virtual memory dump starting at
'addr' of size 'size'", },
     { "pmemsave", "lis", do_physical_memory_save,
       "addr size file", "save to disk physical memory dump starting
at 'addr' of size 'size'", },
+    { "boot_set", "s", do_bootdevice_set,
+      "bootdevice", "define new values for the boot device list" },
     { NULL, NULL, },
 };

diff -Nur -x .svn qemu/trunk/qemu-doc.texi b/qemu-doc.texi
--- qemu/trunk/qemu-doc.texi	2008-04-25 13:57:42.000000000 +0200
+++ b/qemu-doc.texi	2008-04-25 13:54:15.000000000 +0200
@@ -1253,6 +1253,14 @@

 Reset the system.

+@item boot_set @var{bootdevicelist}
+
+Define new values for the boot device list. Those values will override
+the values specified on the command line through the @code{-boot} option.
+
+The values that can be specified here depend on the machine type, but are
+the same that can be specified in the @code{-boot} command line option.
+
 @item usb_add @var{devname}

 Add the USB device @var{devname}.  For details of available devices see
diff -Nur -x .svn qemu/trunk/sysemu.h b/sysemu.h
--- qemu/trunk/sysemu.h	2008-04-25 13:57:42.000000000 +0200
+++ b/sysemu.h	2008-04-25 13:54:15.000000000 +0200
@@ -9,6 +9,11 @@
 extern int vm_running;
 extern const char *qemu_name;

+/* handler to set the boot_device for a specific type of QEMUMachine */
+/* return 0 if success */
+typedef int QEMUMachineSetBootFunc(const char *boot_device);
+extern QEMUMachineSetBootFunc *set_bootdevice_fct;
+
 typedef struct vm_change_state_entry VMChangeStateEntry;
 typedef void VMChangeStateHandler(void *opaque, int running);
 typedef void VMStopHandler(void *opaque, int reason);
diff -Nur -x .svn qemu/trunk/vl.c b/vl.c
--- qemu/trunk/vl.c	2008-04-25 13:57:42.000000000 +0200
+++ b/vl.c	2008-04-25 13:54:15.000000000 +0200
@@ -237,6 +237,7 @@
     const char *file;
     char opt[1024];
 } drives_opt[MAX_DRIVES];
+QEMUMachineSetBootFunc *set_bootdevice_fct;

 static CPUState *cur_cpu;
 static CPUState *next_cpu;