diff options
Diffstat (limited to 'nuttx/arch/arm/src/armv6-m/up_svcall.c')
| -rw-r--r-- | nuttx/arch/arm/src/armv6-m/up_svcall.c | 74 |
1 files changed, 73 insertions, 1 deletions
diff --git a/nuttx/arch/arm/src/armv6-m/up_svcall.c b/nuttx/arch/arm/src/armv6-m/up_svcall.c index ac99cabe0..745800532 100644 --- a/nuttx/arch/arm/src/armv6-m/up_svcall.c +++ b/nuttx/arch/arm/src/armv6-m/up_svcall.c @@ -344,6 +344,78 @@ int up_svcall(int irq, FAR void *context) break; #endif + /* R0=SYS_signal_handler: This a user signal handler callback + * + * void signal_handler(_sa_sigaction_t sighand, int signo, + * FAR siginfo_t *info, FAR void *ucontext); + * + * At this point, the following values are saved in context: + * + * R0 = SYS_signal_handler + * R1 = sighand + * R2 = signo + * R3 = info + * ucontext (on the stack) + */ + +#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS) + case SYS_signal_handler: + { + struct tcb_s *rtcb = sched_self(); + + /* Remember the caller's return address */ + + DEBUGASSERT(rtcb->xcp.sigreturn == 0); + rtcb->xcp.sigreturn = regs[REG_PC]; + + /* Set up to return to the user-space pthread start-up function in + * unprivileged mode. + */ + + regs[REG_PC] = (uint32_t)USERSPACE->signal_handler; + regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR; + + /* Change the parameter ordering to match the expectation of struct + * userpace_s signal_handler. + */ + + regs[REG_R0] = regs[REG_R1]; /* sighand */ + regs[REG_R1] = regs[REG_R2]; /* signal */ + regs[REG_R2] = regs[REG_R3]; /* info */ + + /* The last parameter, arg, is trickier. The arg parameter will + * reside at an offset of 4 from the stack pointer. + */ + + regs[REG_R3] = *(uint32_t*)(regs[REG_SP+4]); + } + break; +#endif + + /* R0=SYS_signal_handler_return: This a user signal handler callback + * + * void signal_handler_return(void); + * + * At this point, the following values are saved in context: + * + * R0 = SYS_signal_handler_return + */ + +#if defined(CONFIG_NUTTX_KERNEL) && !defined(CONFIG_DISABLE_SIGNALS) + case SYS_signal_handler_return: + { + struct tcb_s *rtcb = sched_self(); + + /* Set up to return to the kernel-mode signal dispatching logic. */ + + DEBUGASSERT(rtcb->xcp.sigreturn != 0); + + regs[REG_PC] = rtcb->xcp.sigreturn; + regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR; + } + break; +#endif + /* This is not an architecture-specific system call. If NuttX is built * as a standalone kernel with a system call interface, then all of the * additional system calls must be handled as in the default case. @@ -356,7 +428,7 @@ int up_svcall(int irq, FAR void *context) /* Verify that the SYS call number is within range */ - DEBUGASSERT(cmd < SYS_maxsyscall); + DEBUGASSERT(cmd >= CONFIG_SYS_RESERVED && cmd < SYS_maxsyscall); /* Make sure that there is a no saved syscall return address. We * cannot yet handle nested system calls. |