[XenPPC] [PATCH/RFC] Support Xen console=comX option

[Amos Waterland <apw@xxxxxxxxxx>]

The below patch allows Xen/PPC to support the console=comX option 
that Xen/x86 uses.  With this patch applied, one need simply 
supply CMDLINE="console=com2" on the make invocation to get proper use
of the physical serial port on a JS21.

I will soon split out the pieces for submission, but I am posting this
for now for review of the basic approach.  I'd also like to ask that
someone with a Maple-D apply this patch, undefine BROKEN_SLOF, and tell
me whether they see a panic because we try to prune a path we have just
pruned.  That is, sucessive calls of `p = of_getpeer(p)' on the SLOF I
have flashed on my JS21 produce a handle which when turned into a path
is identical to the previous, so I see this before the loop exits:

 pruning `/ht/isa@8/serial@3f8' from devtree
 pruning `/ht/isa@8/serial@3f8' from devtree
 pruning `/ht/isa@8/serial@3f8' from devtree
 pruning `/ht/isa@8/serial@3f8' from devtree

Note that this patch supercedes the "Command line option for serial port" 
patch I posted earlier.

Signed-off-by: Amos Waterland <apw@xxxxxxxxxx>

---

 Makefile  |    6 ++++--
 boot_of.c |   45 ++++++++++++++++++++++++++++++++-------------
 setup.c   |    4 ++++
 3 files changed, 40 insertions(+), 15 deletions(-)

diff -r 058f2e27476d xen/arch/powerpc/Makefile
--- a/xen/arch/powerpc/Makefile Mon Aug 07 17:49:16 2006 -0500
+++ b/xen/arch/powerpc/Makefile Wed Aug 09 18:38:39 2006 -0400
@@ -83,8 +83,10 @@ physdev.o: ../x86/physdev.c
 
 HDRS += $(wildcard *.h)
 
-CMDLINE = "xen"
-boot_of.o: CFLAGS += -DCMDLINE="\"$(CMDLINE)\""
+# The first token in the arguments will be silently dropped.
+IMAGENAME = xen
+CMDLINE = ""
+boot_of.o: CFLAGS += -DCMDLINE="\"$(IMAGENAME) $(CMDLINE)\""
 
 start.o: boot/start.S
        $(CC) $(CFLAGS) -D__ASSEMBLY__ -c $< -o $@
diff -r 058f2e27476d xen/arch/powerpc/boot_of.c
--- a/xen/arch/powerpc/boot_of.c        Mon Aug 07 17:49:16 2006 -0500
+++ b/xen/arch/powerpc/boot_of.c        Wed Aug 09 19:16:20 2006 -0400
@@ -747,6 +747,8 @@ static void __init boot_of_fix_maple(voi
         }
     }
 }
+
+#define BROKEN_SLOF
     
 static int __init boot_of_serial(void *oftree)
 {
@@ -760,19 +762,37 @@ static int __init boot_of_serial(void *o
     if (n == OF_FAILURE) {
         of_panic("instance-to-package of /chosen/stdout: failed\n");
     }
-
-    /* prune this from the oftree */
-    rc = of_package_to_path(n, buf, sizeof(buf));
-    if (rc == OF_FAILURE) {
-        of_panic("package-to-path of /chosen/stdout: failed\n");
-    }
-    of_printf("Pruning from devtree: %s\n"
-              "  since Xen will be using it for console\n", buf);
+    
+    for (p = of_getpeer(n); p; p = of_getpeer(p)) {
+        rc = of_package_to_path(n, buf, sizeof(buf));
+
+        if (rc == OF_FAILURE) of_panic("package-to-path failed\n");
+
+        of_printf("pruning `%s' from devtree\n", buf);
+#ifndef BROKEN_SLOF
+        rc = ofd_prune_path(oftree, buf);
+#endif
+
+        if (rc < 0) of_panic("prune of `%s' failed\n", buf);
+    }
+
+#ifdef BROKEN_SLOF
+    of_printf("(workaround) pruning `%s' from device tree\n", buf);
     rc = ofd_prune_path(oftree, buf);
-    if (rc < 0) {
-        of_panic("prune path \"%s\" failed\n", buf);
-    }
-    
+    if (rc < 0) of_panic("prune of `%s' failed\n", buf);
+
+    {
+        int len = strlen(buf);
+        char *str = buf + len - sizeof("3f8") + 1;
+
+        if (!strcmp(str, "3f8")) {
+            str[0] = '2';
+            of_printf("(workaround) pruning `%s' from device tree\n", buf);
+            rc = ofd_prune_path(oftree, buf);
+            if (rc < 0) of_panic("prune of `%s' failed\n", buf);
+        }
+    }
+#endif
 
     p = of_getparent(n);
     if (p == OF_FAILURE) {
@@ -799,7 +819,6 @@ static int __init boot_of_serial(void *o
     if (rc == OF_FAILURE) {
         of_panic("%s: no location for serial port\n", __func__);
     }
-    ns16550.io_base = val[1];
 
     ns16550.baud = BAUD_AUTO;
     ns16550.data_bits = 8;
diff -r 058f2e27476d xen/arch/powerpc/setup.c
--- a/xen/arch/powerpc/setup.c  Mon Aug 07 17:49:16 2006 -0500
+++ b/xen/arch/powerpc/setup.c  Wed Aug 09 18:47:08 2006 -0400
@@ -214,7 +214,11 @@ static void __init __start_xen(multiboot
     if ((mbi->flags & MBI_CMDLINE) && (mbi->cmdline != 0))
         cmdline_parse(__va((ulong)mbi->cmdline));
 
+    /* We initialise the serial devices very early so we can get debugging. */
+    ns16550.io_base = 0x3f8;
     ns16550_init(0, &ns16550);
+    ns16550.io_base = 0x2f8;
+    ns16550_init(1, &ns16550);
     serial_init_preirq();
 
     init_console();

_______________________________________________
Xen-ppc-devel mailing list
Xen-ppc-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ppc-devel