When reset code is in flash, the jump instructions emitted by the compiler are relative instead of absolute jumps.
A fix to the reset code to make correct jumps to the beginning of code relocated to RAM have also been added.
Signed-off-by: Julius Baxter juliusbaxter@gmail.com --- arch/openrisc/cpu/cpu.c | 6 +++++- arch/openrisc/cpu/start.S | 13 ++++++++----- 2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/openrisc/cpu/cpu.c b/arch/openrisc/cpu/cpu.c index 25cd624..73ecc6f 100644 --- a/arch/openrisc/cpu/cpu.c +++ b/arch/openrisc/cpu/cpu.c @@ -151,7 +151,11 @@ extern void __reset(void); int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { disable_interrupts(); - __reset(); + /* Code the jump to __reset here as the compiler is prone to + emitting a bad jump instruction if the function is in flash */ + __asm__("l.movhi r1,hi(__reset); \ + l.ori r1,r1,lo(__reset); \ + l.jr r1"); /* not reached, __reset does not return */ return 0; } diff --git a/arch/openrisc/cpu/start.S b/arch/openrisc/cpu/start.S index 3a42717..39c80e1 100644 --- a/arch/openrisc/cpu/start.S +++ b/arch/openrisc/cpu/start.S @@ -26,8 +26,11 @@
#define HANDLE_EXCEPTION \ l.addi r1, r1, -EXCEPTION_STACK_SIZE ;\ + l.sw 0x00(r1), r2 ;\ l.sw 0x1c(r1), r9 ;\ - l.jal _exception_handler ;\ + l.movhi r2,hi(_exception_handler) ;\ + l.ori r2,r2,lo(_exception_handler) ;\ + l.jalr r2 ;\ l.nop ;\ l.lwz r9, 0x1c(r1) ;\ l.addi r1, r1, EXCEPTION_STACK_SIZE ;\ @@ -79,8 +82,9 @@ __reset: l.bnf .L_relocvectors l.addi r4,r4, 4 #endif - - l.j _start + l.movhi r4,hi(_start) + l.ori r4,r4,lo(_start) + l.jr r4 l.nop
/* bus error */ @@ -262,8 +266,7 @@ _start: .type _exception_handler,@function
_exception_handler: - /* Store state (r9 already saved)*/ - l.sw 0x00(r1), r2 + /* Store state (r2 and r9 already saved)*/ l.sw 0x04(r1), r3 l.sw 0x08(r1), r4 l.sw 0x0c(r1), r5