From 4512e4f355b25abfa815d74d4dbba9d994902533 Mon Sep 17 00:00:00 2001
From: hollisb <hollisb@localhost>
Date: Tue, 12 Oct 2004 03:56:10 +0000
Subject: [PATCH] 2004-10-11  Hollis Blanchard  <hollis@penguinppc.org>

    * boot/powerpc/ieee1275/cmain.c (grub_ieee1275_flags): New global.
    (cmain): Accept 3 parameters. Test for 0xdeadbeef, indicating Old
    World Macintosh. If Old Wold, set flag in grub_ieee1275_flags; claim
    Open Firmware's memory for it; claim memory from _start to _end.
    * boot/powerpc/ieee1275/crt0.S (__bss_start): New extern.
    (_end): New extern.
    (_start): Zero BSS from __bss_start to _end.
    * include/grub/powerpc/ieee1275/ieee1275.h (grub_ieee1275_flags):
    New extern.
    (GRUB_IEEE1275_NO_PARTITION_0): New #define.
---
 ChangeLog                                | 13 +++++++++++
 boot/powerpc/ieee1275/cmain.c            | 28 ++++++++++++++++++++++--
 boot/powerpc/ieee1275/crt0.S             | 18 ++++++++++++---
 include/grub/powerpc/ieee1275/ieee1275.h |  5 +++++
 4 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 87c688752..a0e3e40e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2004-10-11  Hollis Blanchard  <hollis@penguinppc.org>
+
+	* boot/powerpc/ieee1275/cmain.c (grub_ieee1275_flags): New global.
+	(cmain): Accept 3 parameters. Test for 0xdeadbeef, indicating Old
+	World Macintosh. If Old Wold, set flag in grub_ieee1275_flags; claim
+	Open Firmware's memory for it; claim memory from _start to _end.
+	* boot/powerpc/ieee1275/crt0.S (__bss_start): New extern.
+	(_end): New extern.
+	(_start): Zero BSS from __bss_start to _end.
+	* include/grub/powerpc/ieee1275/ieee1275.h (grub_ieee1275_flags):
+	New extern.
+	(GRUB_IEEE1275_NO_PARTITION_0): New #define.
+
 2004-10-11  Hollis Blanchard  <hollis@penguinppc.org>
 
     * boot/powerpc/ieee1275/ieee1275.c (grub_ieee1275_claim):
diff --git a/boot/powerpc/ieee1275/cmain.c b/boot/powerpc/ieee1275/cmain.c
index b24504261..0f9366482 100644
--- a/boot/powerpc/ieee1275/cmain.c
+++ b/boot/powerpc/ieee1275/cmain.c
@@ -35,6 +35,8 @@ struct module_info
 /* OpenFirmware entry point passed to us from the real bootloader.  */
 intptr_t (*grub_ieee1275_entry_fn) (void *);
 
+grub_uint32_t grub_ieee1275_flags;
+
 
 /* Return a help text for this architecture.  */
 const char *
@@ -48,14 +50,36 @@ help_arch (void)
 /* Setup the argument vector and pass control over to the main
    function.  */
 void
-cmain (uint32_t firmware_entry)
+cmain (uint32_t r3, uint32_t r4 __attribute__((unused)), uint32_t r5)
 {
   char **argv, args[256];
   grub_ieee1275_phandle_t chosen;
   int argc = 0, actual;
   long batl, batu;
 
-  grub_ieee1275_entry_fn = (intptr_t (*)(void *)) firmware_entry;
+  if (r5 == 0xdeadbeef)
+    {
+      /* Entered from Old World stage1.  */
+      extern char _start;
+      extern char _end;
+
+      grub_ieee1275_entry_fn = (intptr_t (*)(void *)) r3;
+
+      grub_ieee1275_flags = GRUB_IEEE1275_NO_PARTITION_0;
+
+      /* Old World Open Firmware may use 4M-5M without claiming it.  */
+      grub_ieee1275_claim (0x00400000, 0x00100000, 0, 0);
+
+      /* Need to claim ourselves so we don't cannibalize our memory later.  */
+      if (grub_ieee1275_claim ((grub_addr_t) &_start, (grub_addr_t) &_end
+          - (grub_addr_t) &_start, 0, 0))
+	abort();
+    }
+  else
+    {
+      /* Assume we were entered from Open Firmware.  */
+      grub_ieee1275_entry_fn = (intptr_t (*)(void *)) r5;
+    }
 
   /* Initialize BAT registers to unmapped to not generate overlapping
      mappings below.  */
diff --git a/boot/powerpc/ieee1275/crt0.S b/boot/powerpc/ieee1275/crt0.S
index 168999b72..868a83d98 100644
--- a/boot/powerpc/ieee1275/crt0.S
+++ b/boot/powerpc/ieee1275/crt0.S
@@ -32,7 +32,10 @@
 	.long   0xffffffff      /* virt-base */
 	.long   0xffffffff      /* virt-size */
 	.long   0x00030000      /* load-base */
-	
+
+.extern __bss_start
+.extern _end
+
 	.text
 	.align	2
 	.globl	_start
@@ -43,9 +46,18 @@ _start:
 
 	li      2, 0
 	li      13, 0
-	
 
-	mr	3, 5	
+	/* Stage1 won't zero BSS for us. In other cases, why not do it again?  */
+	lis	6, (__bss_start - 4)@h
+	ori	6, 6, (__bss_start - 4)@l
+	lis	7, (_end - 4)@h
+	ori	7, 7, (_end - 4)@l
+	subf	7, 6, 7
+	srwi	7, 7, 2 /* We store 4 bytes at a time.  */
+	mtctr	7
+2:	stwu	2, 4(6) /* We know r2 is already 0 from above.  */
+	bdnz	2b
+
 	bl	cmain
 1:	b	1b
 
diff --git a/include/grub/powerpc/ieee1275/ieee1275.h b/include/grub/powerpc/ieee1275/ieee1275.h
index 495fb85b8..35ae94d71 100644
--- a/include/grub/powerpc/ieee1275/ieee1275.h
+++ b/include/grub/powerpc/ieee1275/ieee1275.h
@@ -44,6 +44,11 @@ typedef intptr_t grub_ieee1275_ihandle_t;
 typedef intptr_t grub_ieee1275_phandle_t;
 
 extern intptr_t (*grub_ieee1275_entry_fn) (void *);
+extern grub_uint32_t grub_ieee1275_flags;
+
+/* Old World firmware fails seek when "dev:0" is opened.  */
+#define GRUB_IEEE1275_NO_PARTITION_0 0x1
+
 
 
 uint32_t EXPORT_FUNC(grub_ieee1275_decode_int_4) (unsigned char *p);