From c55aef0e5bc61539ad5c915c1400103f1c79942e Mon Sep 17 00:00:00 2001
From: Suzuki Poulose <suzuki@in.ibm.com>
Date: Wed, 14 Dec 2011 22:59:57 +0000
Subject: [PATCH] powerpc/boot: Change the load address for the wrapper to fit
 the kernel

The wrapper code which uncompresses the kernel in case of a 'ppc' boot
is by default loaded at 0x00400000 and the kernel will be uncompressed
to fit the location 0-0x00400000. But with dynamic relocations, the size
of the kernel may exceed 0x00400000(4M). This would cause an overlap
of the uncompressed kernel and the boot wrapper, causing a failure in
boot.

The message looks like :

   zImage starting: loaded at 0x00400000 (sp: 0x0065ffb0)
   Allocating 0x5ce650 bytes for kernel ...
   Insufficient memory for kernel at address 0! (_start=00400000, uncompressed size=00591a20)

This patch shifts the load address of the boot wrapper code to the next
higher MB, according to the size of  the uncompressed vmlinux.

With the patch, we get the following message while building the image :

 WARN: Uncompressed kernel (size 0x5b0344) overlaps the address of the wrapper(0x400000)
 WARN: Fixing the link_address of wrapper to (0x600000)

Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@gmail.com>
---
 arch/powerpc/boot/wrapper | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/powerpc/boot/wrapper b/arch/powerpc/boot/wrapper
index eb78e437ec1b4..3790dcd13640a 100755
--- a/arch/powerpc/boot/wrapper
+++ b/arch/powerpc/boot/wrapper
@@ -260,6 +260,8 @@ vmz="$tmpdir/`basename \"$kernel\"`.$ext"
 if [ -z "$cacheit" -o ! -f "$vmz$gzip" -o "$vmz$gzip" -ot "$kernel" ]; then
     ${CROSS}objcopy $objflags "$kernel" "$vmz.$$"
 
+    strip_size=$(stat -c %s $vmz.$$)
+
     if [ -n "$gzip" ]; then
         gzip -n -f -9 "$vmz.$$"
     fi
@@ -269,6 +271,24 @@ if [ -z "$cacheit" -o ! -f "$vmz$gzip" -o "$vmz$gzip" -ot "$kernel" ]; then
     else
 	vmz="$vmz.$$"
     fi
+else
+    # Calculate the vmlinux.strip size
+    ${CROSS}objcopy $objflags "$kernel" "$vmz.$$"
+    strip_size=$(stat -c %s $vmz.$$)
+    rm -f $vmz.$$
+fi
+
+# Round the size to next higher MB limit
+round_size=$(((strip_size + 0xfffff) & 0xfff00000))
+
+round_size=0x$(printf "%x" $round_size)
+link_addr=$(printf "%d" $link_address)
+
+if [ $link_addr -lt $strip_size ]; then
+    echo "WARN: Uncompressed kernel (size 0x$(printf "%x\n" $strip_size))" \
+		"overlaps the address of the wrapper($link_address)"
+    echo "WARN: Fixing the link_address of wrapper to ($round_size)"
+    link_address=$round_size
 fi
 
 vmz="$vmz$gzip"
-- 
GitLab