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author | Robert Morris <[email protected]> | 2022-08-22 13:49:15 -0400 |
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committer | Robert Morris <[email protected]> | 2022-08-22 13:49:15 -0400 |
commit | 63ef3b8c9fd15d5ea5775813cda94a3c64cff0d3 (patch) | |
tree | 13a80865f2ef47967f19777bb57e7632dfc73247 /kernel/trap.c | |
parent | f2ee8690addf0aa52b5de2061fe6d659574406f9 (diff) | |
download | xv6-labs-63ef3b8c9fd15d5ea5775813cda94a3c64cff0d3.tar.gz xv6-labs-63ef3b8c9fd15d5ea5775813cda94a3c64cff0d3.tar.bz2 xv6-labs-63ef3b8c9fd15d5ea5775813cda94a3c64cff0d3.zip |
slightly better comments
Diffstat (limited to 'kernel/trap.c')
-rw-r--r-- | kernel/trap.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trap.c b/kernel/trap.c index 75fb3ec..524da44 100644 --- a/kernel/trap.c +++ b/kernel/trap.c @@ -60,8 +60,8 @@ usertrap(void) // but we want to return to the next instruction. p->trapframe->epc += 4; - // an interrupt will change sstatus &c registers, - // so don't enable until done with those registers. + // an interrupt will change sepc, scause, and sstatus, + // so enable only now that we're done with those registers. intr_on(); syscall(); @@ -101,7 +101,7 @@ usertrapret(void) w_stvec(trampoline_uservec); // set up trapframe values that uservec will need when - // the process next re-enters the kernel. + // the process next traps into the kernel. p->trapframe->kernel_satp = r_satp(); // kernel page table p->trapframe->kernel_sp = p->kstack + PGSIZE; // process's kernel stack p->trapframe->kernel_trap = (uint64)usertrap; |