diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/defs.h | 1 | ||||
| -rw-r--r-- | kernel/exec.c | 1 | ||||
| -rw-r--r-- | kernel/plic.c | 14 | ||||
| -rw-r--r-- | kernel/proc.h | 2 | ||||
| -rw-r--r-- | kernel/spinlock.c | 9 |
5 files changed, 8 insertions, 19 deletions
diff --git a/kernel/defs.h b/kernel/defs.h index f893d28..9c5f643 100644 --- a/kernel/defs.h +++ b/kernel/defs.h @@ -173,7 +173,6 @@ int copyinstr(pagetable_t, char *, uint64, uint64); // plic.c void plicinit(void); void plicinithart(void); -uint64 plic_pending(void); int plic_claim(void); void plic_complete(int); diff --git a/kernel/exec.c b/kernel/exec.c index 74ef654..6a51499 100644 --- a/kernel/exec.c +++ b/kernel/exec.c @@ -112,6 +112,7 @@ exec(char *path, char **argv) p->tf->epc = elf.entry; // initial program counter = main p->tf->sp = sp; // initial stack pointer proc_freepagetable(oldpagetable, oldsz); + return argc; // this ends up in a0, the first argument to main(argc, argv) bad: diff --git a/kernel/plic.c b/kernel/plic.c index b569492..eed8316 100644 --- a/kernel/plic.c +++ b/kernel/plic.c @@ -28,20 +28,6 @@ plicinithart(void) *(uint32*)PLIC_SPRIORITY(hart) = 0; } -// return a bitmap of which IRQs are waiting -// to be served. -uint64 -plic_pending(void) -{ - uint64 mask; - - //mask = *(uint32*)(PLIC + 0x1000); - //mask |= (uint64)*(uint32*)(PLIC + 0x1004) << 32; - mask = *(uint64*)PLIC_PENDING; - - return mask; -} - // ask the PLIC what interrupt we should serve. int plic_claim(void) diff --git a/kernel/proc.h b/kernel/proc.h index 538b48a..812c769 100644 --- a/kernel/proc.h +++ b/kernel/proc.h @@ -95,7 +95,7 @@ struct proc { int pid; // Process ID // these are private to the process, so p->lock need not be held. - uint64 kstack; // Bottom of kernel stack for this process + uint64 kstack; // Virtual address of kernel stack uint64 sz; // Size of process memory (bytes) pagetable_t pagetable; // Page table struct trapframe *tf; // data page for trampoline.S diff --git a/kernel/spinlock.c b/kernel/spinlock.c index 563532e..f192832 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -34,7 +34,8 @@ acquire(struct spinlock *lk) // Tell the C compiler and the processor to not move loads or stores // past this point, to ensure that the critical section's memory - // references happen after the lock is acquired. + // references happen strictly after the lock is acquired. + // On RISC-V, this emits a fence instruction. __sync_synchronize(); // Record info about lock acquisition for holding() and debugging. @@ -52,8 +53,10 @@ release(struct spinlock *lk) // Tell the C compiler and the CPU to not move loads or stores // past this point, to ensure that all the stores in the critical - // section are visible to other CPUs before the lock is released. - // On RISC-V, this turns into a fence instruction. + // section are visible to other CPUs before the lock is released, + // and that loads in the critical section occur strictly before + // the lock is released. + // On RISC-V, this emits a fence instruction. __sync_synchronize(); // Release the lock, equivalent to lk->locked = 0. |