ref: bbe261d58359dbbcfc2f0108323f3fae688a568c
dir: /os/ip/kernel.h/
extern int kclose(int); extern int kdial(char*, char*, char*, int*); extern int kannounce(char*, char*); extern void kerrstr(char*); extern void kgerrstr(char*); extern int kopen(char*, int); extern long kread(int, void*, long); extern long kseek(int, vlong, int); extern long kwrite(int, void*, long); extern void kwerrstr(char *, ...);