From: Ameet Paranjape <aparanja@redhat.com>
Date: Thu, 2 Oct 2008 18:34:46 -0400
Subject: [ppc64] netboot image too large
Message-id: 20081002223446.21610.33300.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH RHEL5.3 BZ462663] Netboot image for ppc too large
Bugzilla: 462663
RH-Acked-by: David Howells <dhowells@redhat.com>

RHBZ#:462663
======
https://bugzilla.redhat.com/show_bug.cgi?id=462663

Description:
===========
The size of the RHEL netboot image has grown resulting in it being too large
for open firmware to support.  As a result, the network boot hangs with no
indication of root cause.

This patch extends the amount of memory available to the system during boot.
Specifically, the real-base is set to 2000000, RMA is increased to 128,
and large page support is added.  The result is images larger than 4MB will
boot.

RHEL Version Found:
================
RHEL 5.2

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1500435

Upstream Status:
================
This patch is in the process of being posted for upstream acceptance.

Test Status:
============
Initial tests have indicated the patch works.  A zImage was created based on
the patch kernel which was netbooted.  Without the patch the kernel does not
boot.

===============================================================

Ameet Paranjape 978-392-3903 ext 23903
IBM on-site partner

Proposed Patch:
===============

diff --git a/arch/powerpc/boot/addnote.c b/arch/powerpc/boot/addnote.c
index 8041a98..fb0228b 100644
--- a/arch/powerpc/boot/addnote.c
+++ b/arch/powerpc/boot/addnote.c
@@ -25,7 +25,7 @@ char arch[] = "PowerPC";
 #define N_DESCR	6
 unsigned int descr[N_DESCR] = {
 	0xffffffff,		/* real-mode = true */
-	0x00c00000,		/* real-base, i.e. where we expect OF to be */
+	0x02000000,		/* real-base, i.e. where we expect OF to be */
 	0xffffffff,		/* real-size */
 	0xffffffff,		/* virt-base */
 	0xffffffff,		/* virt-size */
@@ -41,16 +41,18 @@ char rpaname[] = "IBM,RPA-Client-Config";
  * it looks at the splpar field at least.  So these values need to be
  * reasonable.
  */
-#define N_RPA_DESCR	8
+#define N_RPA_DESCR	10
 unsigned int rpanote[N_RPA_DESCR] = {
-	0,			/* lparaffinity */
-	64,			/* min_rmo_size */
+	1,			/* lparaffinity */
+	128,			/* min_rmo_size */
 	0,			/* min_rmo_percent */
-	40,			/* max_pft_size */
+	46,			/* max_pft_size */
 	1,			/* splpar */
 	-1,			/* min_load */
 	0,			/* new_mem_def */
-	1,			/* ignore_my_client_config */
+	0,			/* ignore_my_client_config */
+	1,			/* large_page_ready */
+	0,			/* force_alpha_mode */
 };
 
 #define ROUNDUP(len)	(((len) + 3) & ~3)
diff --git a/arch/powerpc/boot/zImage.lds b/arch/powerpc/boot/zImage.lds
index 4b6bb3f..0d0046d 100644
--- a/arch/powerpc/boot/zImage.lds
+++ b/arch/powerpc/boot/zImage.lds
@@ -2,7 +2,7 @@ OUTPUT_ARCH(powerpc:common)
 ENTRY(_zimage_start)
 SECTIONS
 {
-  . = (4*1024*1024);
+  . = (56*1024*1024);
   _start = .;
   .text      :
   {
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index e31088a..a3eb953 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -663,10 +663,10 @@ static unsigned char ibm_architecture_vec[] = {
 	W(0xffffffff),			/* virt_base */
 	W(0xffffffff),			/* virt_size */
 	W(0xffffffff),			/* load_base */
-	W(64),				/* 128MB min RMA */
+	W(128),				/* 128MB min RMA */
 	W(0xffffffff),			/* full client load */
 	0,				/* min RMA percentage of total RAM */
-	48,				/* max log_2(hash table size) */
+	46,				/* max log_2(hash table size) */
 
 	/* option vector 3: processor options supported */
 	3 - 2,				/* length */
@@ -715,6 +715,8 @@ static struct fake_elf {
 			u32	min_load;
 			u32	new_mem_def;
 			u32	ignore_me;
+			u32	large_page_ready;
+			u32	force_alpha_mode;
 		} rpadesc;
 	} rpanote;
 } fake_elf = {
@@ -759,13 +761,14 @@ static struct fake_elf {
 		.type = 0x12759999,
 		.name = "IBM,RPA-Client-Config",
 		.rpadesc = {
-			.lpar_affinity = 0,
-			.min_rmo_size = 64,	/* in megabytes */
+			.lpar_affinity = 1,
+			.min_rmo_size = 128,	/* in megabytes */
 			.min_rmo_percent = 0,
-			.max_pft_size = 48,	/* 2^48 bytes max PFT size */
+			.max_pft_size = 46,	/* 2^46 bytes max PFT size */
 			.splpar = 1,
 			.min_load = ~0U,
-			.new_mem_def = 0
+			.new_mem_def = 0,
+			.large_page_ready = 1
 		}
 	}
 };