[U-Boot] [PATCH 05/17] ppc: Don't initialize write protected NOR flashes

Peter Tyser ptyser at xes-inc.com
Wed Sep 29 21:05:44 CEST 2010


From: John Schmoller <jschmoller at xes-inc.com>

If a NOR flash is write protected it can not be initialized/detected so
add the ability for boards to skip NOR initialization on bootup.  A
board can skip NOR initialization by implementing the
board_flash_wp_on() function.

Signed-off-by: John Schmoller <jschmoller at xes-inc.com>
Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
CC: sr at denx.de
---
 arch/powerpc/lib/board.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/lib/board.c b/arch/powerpc/lib/board.c
index 8f6a7c9..a105e1c 100644
--- a/arch/powerpc/lib/board.c
+++ b/arch/powerpc/lib/board.c
@@ -175,6 +175,16 @@ void __board_add_ram_info(int use_default)
 }
 void board_add_ram_info(int) __attribute__((weak, alias("__board_add_ram_info")));
 
+int __board_flash_wp_on(void)
+{
+	/*
+	 * Most flashes can't be detected when write protection is enabled,
+	 * so provide a way to let U-Boot gracefully ignore write protected
+	 * devices.
+	 */
+	return 0;
+}
+int board_flash_wp_on(void) __attribute__((weak, alias("__board_flash_wp_on")));
 
 static int init_func_ram (void)
 {
@@ -703,7 +713,11 @@ void board_init_r (gd_t *id, ulong dest_addr)
 #if !defined(CONFIG_SYS_NO_FLASH)
 	puts ("FLASH: ");
 
-	if ((flash_size = flash_init ()) > 0) {
+	if (board_flash_wp_on()) {
+		printf("Uninitialized - Write Protect On\n");
+		/* Since WP is on, we can't find real size.  Set to 0 */
+		flash_size = 0;
+	} else if ((flash_size = flash_init ()) > 0) {
 # ifdef CONFIG_SYS_FLASH_CHECKSUM
 		print_size (flash_size, "");
 		/*
-- 
1.7.0.4



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