From 4377351db43c94d400124a3948a0e70bde878289 Mon Sep 17 00:00:00 2001
From: Florian Fainelli <florian@openwrt.org>
Date: Mon, 26 Mar 2007 07:32:10 +0000
Subject: [PATCH] Preserve fw_arg0-3 to allow runtime bootloader detection
 (Gabor Juhos)

SVN-Revision: 6711
---
 .../image/lzma-loader/src/decompress.c        | 12 +++++-
 .../adm5120-2.6/image/lzma-loader/src/head.S  | 43 ++++++++++++-------
 2 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/target/linux/adm5120-2.6/image/lzma-loader/src/decompress.c b/target/linux/adm5120-2.6/image/lzma-loader/src/decompress.c
index b0ed2fc8c4..d3610241f6 100644
--- a/target/linux/adm5120-2.6/image/lzma-loader/src/decompress.c
+++ b/target/linux/adm5120-2.6/image/lzma-loader/src/decompress.c
@@ -30,6 +30,9 @@
  * 24-Apr-2005 Oleg I. Vdovikin
  *   reordered functions using lds script, removed forward decl
  *
+ * 24-Mar-2007 Gabor Juhos
+ *   pass original values of the a0,a1,a2,a3 registers to the kernel
+ *
  */
 
 #include "LzmaDecode.h"
@@ -93,6 +96,9 @@ extern unsigned char workspace[];
 unsigned int offset;
 unsigned char *data;
 
+typedef void (*kernel_entry)(unsigned long reg_a0, unsigned long reg_a1,
+	unsigned long reg_a2, unsigned long reg_a3);
+
 /* flash access should be aligned, so wrapper is used */
 /* read byte from the flash, all accesses are 32-bit aligned */
 static int read_byte(void *object, unsigned char **buffer, UInt32 *bufferSize)
@@ -119,7 +125,9 @@ static __inline__ unsigned char get_byte(void)
 }
 
 /* should be the first function */
-void entry(unsigned long icache_size, unsigned long icache_lsize, 
+void entry(unsigned long reg_a0, unsigned long reg_a1,
+	unsigned long reg_a2, unsigned long reg_a3,
+	unsigned long icache_size, unsigned long icache_lsize, 
 	unsigned long dcache_size, unsigned long dcache_lsize)
 {
 	unsigned int i;  /* temp value */
@@ -173,7 +181,7 @@ void entry(unsigned long icache_size, unsigned long icache_lsize,
 
 		/* Jump to load address */
         uart_write_str("ok\r\n");
-		((void (*)(void)) LOADADDR)();
+		((kernel_entry) LOADADDR)(reg_a0, reg_a1, reg_a2, reg_a3);
 	}
     uart_write_str("failed\r\n");
     while (1 );
diff --git a/target/linux/adm5120-2.6/image/lzma-loader/src/head.S b/target/linux/adm5120-2.6/image/lzma-loader/src/head.S
index 9bfbd53d51..7f0e9adc0d 100644
--- a/target/linux/adm5120-2.6/image/lzma-loader/src/head.S
+++ b/target/linux/adm5120-2.6/image/lzma-loader/src/head.S
@@ -1,3 +1,6 @@
+/* Copyright 2007 Gabor Juhos				*/
+/* keep original values of the a0,a1,a2,a3 registers	*/
+/* cache manipulation adapted from Broadcom code 	*/
 /* Copyright 2005 Oleg I. Vdovikin (oleg@cs.msu.su)	*/
 /* cache manipulation adapted from Broadcom code 	*/
 /* idea taken from original bunzip2 decompressor code	*/
@@ -40,18 +43,17 @@
 	.set noreorder
 	
 	/* Copy decompressor code to the right place */
-	li	t2, BZ_TEXT_START
-	add	a0, t2, 0
-	la      a1, code_start
-	la	a2, code_stop
+	li	t0, BZ_TEXT_START
+
+	la      t1, code_start
+	la	t2, code_stop
 $L1:
-	lw	t0, 0(a1)
-	sw	t0, 0(a0)
-	add	a1, 4
-	add	a0, 4
-	blt	a1, a2, $L1
-	nop
-	
+	lw	t3, 0(t1)
+	sw	t3, 0(t0)
+	add	t1, 4
+	blt	t1, t2, $L1
+	add	t0, 4
+
 	/* At this point we need to invalidate dcache and */
 	/* icache before jumping to new code */
 
@@ -145,11 +147,20 @@ nodc:
 	addu	t0,s3
 
 noic:
-	move	a0,s3			/* icache line size */
-	move	a1,s4			/* icache size */
-	move	a2,s1			/* dcache line size */
-	jal	t2
-	move	a3,s2			/* dcache size */
+	li	t0, BZ_TEXT_START
+	
+	addiu	sp, -32			/* reserve stack for parameters */
+#if 0	
+	sw	a0, 0(sp)
+	sw	a1, 4(sp)
+	sw	a2, 8(sp)
+	sw	a3, 12(sp)
+#endif	
+	sw	s3, 16(sp)		/* icache line size */
+	sw	s4, 20(sp)		/* icache size */
+	sw	s1, 24(sp)		/* dcache line size */
+	jr	t0
+	sw	s2, 28(sp)		/* dcache size */
 	
 	.set reorder
 	END(startup)