microblaze: Do not copy reset vectors/manual reset vector setup
Reset vector can be setup by bootloader and kernel doens't need
to touch it. If you require to setup reset vector, please use
CONFIG_MANUAL_RESET_VECTOR throught menuconfig.
It is not possible to setup address 0x0 as reset address because
make no sense to set it up at all.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: John Williams <john.williams@petalogix.com>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 050aca3..922c419 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -184,6 +184,17 @@
hex "Maximum low memory size (in bytes)" if LOWMEM_SIZE_BOOL
default "0x30000000"
+config MANUAL_RESET_VECTOR
+ hex "Microblaze reset vector address setup"
+ default "0x0"
+ help
+ Set this option to have the kernel override the CPU Reset vector.
+ If zero, no change will be made to the MicroBlaze reset vector at
+ address 0x0.
+ If non-zero, a jump instruction to this address, will be written
+ to the reset vector at address 0x0.
+ If you are unsure, set it to default value 0x0.
+
config KERNEL_START_BOOL
bool "Set custom kernel base address"
depends on ADVANCED_OPTIONS
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 6b40524..ca15bc5 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -993,11 +993,10 @@
/* These are compiled and loaded into high memory, then
* copied into place in mach_early_setup */
.section .init.ivt, "ax"
+#if CONFIG_MANUAL_RESET_VECTOR
.org 0x0
- /* this is very important - here is the reset vector */
- /* in current MMU branch you don't care what is here - it is
- * used from bootloader site - but this is correct for FS-BOOT */
- brai 0x70
+ brai CONFIG_MANUAL_RESET_VECTOR
+#endif
.org 0x8
brai TOPHYS(_user_exception); /* syscall handler */
.org 0x10
diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index 9312fbb..8e2c09b 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -95,7 +95,8 @@
void __init machine_early_init(const char *cmdline, unsigned int ram,
unsigned int fdt, unsigned int msr)
{
- unsigned long *src, *dst = (unsigned long *)0x0;
+ unsigned long *src, *dst;
+ unsigned int offset = 0;
/* If CONFIG_MTD_UCLINUX is defined, assume ROMFS is at the
* end of kernel. There are two position which we want to check.
@@ -168,7 +169,14 @@
"CPU have it %x\n", msr);
#endif
- for (src = __ivt_start; src < __ivt_end; src++, dst++)
+ /* Do not copy reset vectors. offset = 0x2 means skip the first
+ * two instructions. dst is pointer to MB vectors which are placed
+ * in block ram. If you want to copy reset vector setup offset to 0x0 */
+#if !CONFIG_MANUAL_RESET_VECTOR
+ offset = 0x2;
+#endif
+ dst = (unsigned long *) (offset * sizeof(u32));
+ for (src = __ivt_start + offset; src < __ivt_end; src++, dst++)
*dst = *src;
/* Initialize global data */