diff options
Diffstat (limited to 'arch/arc/kernel/process.c')
| -rw-r--r-- | arch/arc/kernel/process.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c index cad66851e0c..fdd89715d2d 100644 --- a/arch/arc/kernel/process.c +++ b/arch/arc/kernel/process.c @@ -55,10 +55,8 @@ asmlinkage void ret_from_fork(void); * | ... | * | unused | * | | - * ------------------ <==== top of Stack (thread.ksp) - * | UNUSED 1 word| * ------------------ - * | r25 | + * | r25 | <==== top of Stack (thread.ksp) * ~ ~ * | --to-- | (CALLEE Regs of user mode) * | r13 | @@ -76,7 +74,10 @@ asmlinkage void ret_from_fork(void); * | --to-- | (scratch Regs of user mode) * | r0 | * ------------------ - * | UNUSED 1 word| + * | SP | + * | orig_r0 | + * | event/ECR | + * | user_r25 | * ------------------ <===== END of PAGE */ int copy_thread(unsigned long clone_flags, @@ -150,6 +151,29 @@ int copy_thread(unsigned long clone_flags, } /* + * Do necessary setup to start up a new user task + */ +void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp) +{ + set_fs(USER_DS); /* user space */ + + regs->sp = usp; + regs->ret = pc; + + /* + * [U]ser Mode bit set + * [L] ZOL loop inhibited to begin with - cleared by a LP insn + * Interrupts enabled + */ + regs->status32 = STATUS_U_MASK | STATUS_L_MASK | + STATUS_E1_MASK | STATUS_E2_MASK; + + /* bogus seed values for debugging */ + regs->lp_start = 0x10; + regs->lp_end = 0x80; +} + +/* * Some archs flush debug and FPU info here */ void flush_thread(void) |