Re: [PATCH] export -boot parameter as qemu_boot{0,1,2}

[Robert Millan <rmh@aybabtu.com>]

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On Mon, Jun 29, 2009 at 12:09:16AM -0400, Pavel Roskin wrote:
> On Sat, 2009-06-27 at 14:12 +0200, Robert Millan wrote:
> > This patch makes GRUB gather the -boot parameter from CMOS and
> > export it as a set of variables (qemu_boot{0,1,2}), which can
> > be observed in grub.cfg scripts.
> 
> I think qemu constants belong to a separate header.

Ok, done.

> Please use ARRAY_SIZE to calculate the number of elements.

Done.

> Use of a nested function seems totally unwarranted.

I did it to make the code more readable.  Declaring functions that will
be used locally inside their scope improves code clarity and prevents
mistakes (like attempting to run them from somewhere else).

> We actually agreed
> a while ago that they are bad, but nobody had time to remove them.

I didn't participate in that discussion.  Did Marco and Okuji agree with this?

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."

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2009-06-29  Robert Millan  <rmh.grub@aybabtu.com>

	* include/grub/i386/qemu/init.h: Include `<grub/cpu/cmos.h>'.
	(QEMU_CMOS_BOOT_DEVICE_01, QEMU_CMOS_BOOT_DEVICE_2)
	(QEMU_CMOS_BOOT_FLOPPY, QEMU_CMOS_BOOT_HDD)
	(QEMU_CMOS_BOOT_CDROM, QEMU_CMOS_BOOT_NETWORK): New macros.

	* kern/i386/coreboot/init.c [GRUB_MACHINE_QEMU]
	(grub_machine_init): Initialize `qemu_bootX' variables using
	the CMOS values corresponding to `-boot' parameter in QEMU
	command-line.

Index: kern/i386/coreboot/init.c
===================================================================
--- kern/i386/coreboot/init.c	(revision 2371)
+++ kern/i386/coreboot/init.c	(working copy)
@@ -125,6 +125,45 @@ grub_machine_init (void)
   grub_machine_mmap_iterate (heap_init);
 
   grub_tsc_init ();
+
+#ifdef GRUB_MACHINE_QEMU
+  {
+    grub_uint8_t device[3];
+    unsigned int i, j;
+
+    device[0] = grub_cmos_read (QEMU_CMOS_BOOT_DEVICE_01) & 0x0f;
+    device[1] = grub_cmos_read (QEMU_CMOS_BOOT_DEVICE_01) >> 4;
+    device[2] = grub_cmos_read (QEMU_CMOS_BOOT_DEVICE_2) >> 4;
+
+    auto void qemu_boot_ata (int n, int ata);
+    void qemu_boot_ata (int n, int ata)
+      {
+	char ata_device[] = "ataX";
+	char qemu_boot[] = "qemu_bootX";
+
+	qemu_boot[9] = n + '0';
+	ata_device[3] = ata + '0';
+
+	grub_env_set (qemu_boot, ata_device);
+      }
+
+    j = 0;
+    for (i = 0; i < ARRAY_SIZE (device); i++)
+      switch (device[i])
+	{
+	case QEMU_CMOS_BOOT_HDD:
+	  qemu_boot_ata (j++, 0);
+	  break;
+	case QEMU_CMOS_BOOT_CDROM:
+	  qemu_boot_ata (j++, 2);
+	  break;
+	case QEMU_CMOS_BOOT_FLOPPY:
+	case QEMU_CMOS_BOOT_NETWORK:
+	default:
+	  break;
+	}
+  }
+#endif
 }
 
 void
Index: include/grub/i386/qemu/init.h
===================================================================
--- include/grub/i386/qemu/init.h	(revision 2371)
+++ include/grub/i386/qemu/init.h	(working copy)
@@ -1 +1,33 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2009  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_INIT_I386_QEMU_HEADER
+#define GRUB_INIT_I386_QEMU_HEADER 1
+
+#include <grub/cpu/cmos.h>
 #include <grub/i386/coreboot/init.h>
+
+#define QEMU_CMOS_BOOT_DEVICE_01	0x3d
+#define QEMU_CMOS_BOOT_DEVICE_2		0x38
+
+#define QEMU_CMOS_BOOT_FLOPPY		0x01
+#define QEMU_CMOS_BOOT_HDD		0x02
+#define QEMU_CMOS_BOOT_CDROM		0x03
+#define QEMU_CMOS_BOOT_NETWORK		0x04
+
+#endif