ARM: OMAP: Fixed rebooting

Rebooting has been broken since 2.6.12-rc5 when SRAM code was added.
SRAM code added resetting of SRAM, which killed reboot. Looks like
reboot needs some bootloader code in SRAM to jump to flash for reboot
to work.

diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
index a4daf0f193a970efc0db10c7c91d938bd1bde8fc..e7e07b4c9613e096d827b365bc3417c474ce4e70 100644 (file)
--- a/arch/arm/plat-omap/sram.c
+++ b/arch/arm/plat-omap/sram.c
@@ -24,6 +24,7 @@
 
 #define OMAP1_SRAM_BASE                0xd0000000
 #define OMAP1_SRAM_START       0x20000000
+#define SRAM_BOOTLOADER_SZ     0x80
 
 static unsigned long omap_sram_base;
 static unsigned long omap_sram_size;
@@ -74,7 +75,13 @@ void __init omap_map_sram(void)
        omap_sram_io_desc[0].length = (omap_sram_size + PAGE_SIZE-1)/PAGE_SIZE;
        omap_sram_io_desc[0].length *= PAGE_SIZE;
        iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));
-       memset((void *)omap_sram_base, 0, omap_sram_size);
+
+       /*
+        * Looks like we need to preserve some bootloader code at the
+        * beginning of SRAM for jumping to flash for reboot to work...
+        */
+       memset((void *)omap_sram_base + SRAM_BOOTLOADER_SZ, 0,
+              omap_sram_size - SRAM_BOOTLOADER_SZ);
 }
 
 static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl) = NULL;
@@ -89,7 +96,7 @@ void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
 
 void * omap_sram_push(void * start, unsigned long size)
 {
-       if (size > (omap_sram_ceil - omap_sram_base)) {
+       if (size > (omap_sram_ceil - (omap_sram_base + SRAM_BOOTLOADER_SZ))) {
                printk(KERN_ERR "Not enough space in SRAM\n");
                return NULL;
        }