4 files changed, 47 insertions, 4 deletions

diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c
index f7a184b6c35b..78aaf4ffd7ab 100644
--- a/arch/powerpc/boot/main.c
+++ b/arch/powerpc/boot/main.c
@@ -32,9 +32,16 @@ static struct addr_range prep_kernel(void)
 	void *addr = 0;
 	struct elf_info ei;
 	long len;
+	int uncompressed_image = 0;
 
-	partial_decompress(vmlinuz_addr, vmlinuz_size,
+	len = partial_decompress(vmlinuz_addr, vmlinuz_size,
 		elfheader, sizeof(elfheader), 0);
+	/* assume uncompressed data if -1 is returned */
+	if (len == -1) {
+		uncompressed_image = 1;
+		memcpy(elfheader, vmlinuz_addr, sizeof(elfheader));
+		printf("No valid compressed data found, assume uncompressed data\n\r");
+	}
 
 	if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
 		fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
@@ -67,6 +74,13 @@ static struct addr_range prep_kernel(void)
 					"device tree\n\r");
 	}
 
+	if (uncompressed_image) {
+		memcpy(addr, vmlinuz_addr + ei.elfoffset, ei.loadsize);
+		printf("0x%lx bytes of uncompressed data copied\n\r",
+		       ei.loadsize);
+		goto out;
+	}
+
 	/* Finally, decompress the kernel */
 	printf("Decompressing (0x%p <- 0x%p:0x%p)...\n\r", addr,
 	       vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
@@ -82,7 +96,7 @@ static struct addr_range prep_kernel(void)
 			 len, ei.loadsize);
 
 	printf("Done! Decompressed 0x%lx bytes\n\r", len);
-
+out:
 	flush_cache(addr, ei.loadsize);
 
 	return (struct addr_range){addr, ei.memsize};
@@ -218,8 +232,12 @@ void start(void)
 		console_ops.close();
 
 	kentry = (kernel_entry_t) vmlinux.addr;
-	if (ft_addr)
-		kentry(ft_addr, 0, NULL);
+	if (ft_addr) {
+		if(platform_ops.kentry)
+			platform_ops.kentry(ft_addr, vmlinux.addr);
+		else
+			kentry(ft_addr, 0, NULL);
+	}
 	else
 		kentry((unsigned long)initrd.addr, initrd.size,
 		       loader_info.promptr);
diff --git a/arch/powerpc/boot/opal-calls.S b/arch/powerpc/boot/opal-calls.S
index ff2f1b97bc53..2a99fc9a3ccf 100644
--- a/arch/powerpc/boot/opal-calls.S
+++ b/arch/powerpc/boot/opal-calls.S
@@ -12,6 +12,19 @@
 
 	.text
 
+	.globl opal_kentry
+opal_kentry:
+	/* r3 is the fdt ptr */
+	mtctr r4
+	li	r4, 0
+	li	r5, 0
+	li	r6, 0
+	li	r7, 0
+	ld	r11,opal@got(r2)
+	ld	r8,0(r11)
+	ld	r9,8(r11)
+	bctr
+
 #define OPAL_CALL(name, token)				\
 	.globl name;					\
 name:							\
diff --git a/arch/powerpc/boot/opal.c b/arch/powerpc/boot/opal.c
index 1f37e1c1d6d8..d7b4fd47eb44 100644
--- a/arch/powerpc/boot/opal.c
+++ b/arch/powerpc/boot/opal.c
@@ -23,14 +23,25 @@ struct opal {
 
 static u32 opal_con_id;
 
+/* see opal-wrappers.S */
 int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
 int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
 int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
 int64_t opal_console_flush(uint64_t term_number);
 int64_t opal_poll_events(uint64_t *outstanding_event_mask);
 
+void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr);
+
 static int opal_con_open(void)
 {
+	/*
+	 * When OPAL loads the boot kernel it stashes the OPAL base and entry
+	 * address in r8 and r9 so the kernel can use the OPAL console
+	 * before unflattening the devicetree. While executing the wrapper will
+	 * probably trash r8 and r9 so this kentry hook restores them before
+	 * entering the decompressed kernel.
+	 */
+	platform_ops.kentry = opal_kentry;
 	return 0;
 }
 
diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 309d1b127e96..fad1862f4b2d 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -30,6 +30,7 @@ struct platform_ops {
 	void *	(*realloc)(void *ptr, unsigned long size);
 	void	(*exit)(void);
 	void *	(*vmlinux_alloc)(unsigned long size);
+	void  	(*kentry)(unsigned long fdt_addr, void *vmlinux_addr);
 };
 extern struct platform_ops platform_ops;