/* * The supporting library for applications. * Actually, supporting routines for applications are catalogued as the user * library. we don't do that in PKE to make the relationship between application * and user library more straightforward. */ #include "user_lib.h" #include "util/types.h" #include "util/snprintf.h" #include "kernel/syscall.h" uint64 do_user_call(uint64 sysnum, uint64 a1, uint64 a2, uint64 a3, uint64 a4, uint64 a5, uint64 a6, uint64 a7) { int ret; // before invoking the syscall, arguments of do_user_call are already loaded into the argument // registers (a0-a7) of our (emulated) risc-v machine. asm volatile( "ecall\n" "sw a0, %0" // returns a 32-bit value : "=m"(ret) : : "memory"); return ret; } // // printu() supports user/lab1_1_helloworld.c // int printu(const char* s, ...) { va_list vl; va_start(vl, s); char out[256]; // fixed buffer size. int res = vsnprintf(out, sizeof(out), s, vl); va_end(vl); const char* buf = out; size_t n = res < sizeof(out) ? res : sizeof(out); // make a syscall to implement the required functionality. return do_user_call(SYS_user_print, (uint64)buf, n, 0, 0, 0, 0, 0); } // // applications need to call exit to quit execution. // int exit(int code) { return do_user_call(SYS_user_exit, code, 0, 0, 0, 0, 0, 0); } // // lib call to naive_malloc // void* naive_malloc() { return (void*)do_user_call(SYS_user_allocate_page, 0, 0, 0, 0, 0, 0, 0); } // // lib call to naive_free // void naive_free(void* va) { do_user_call(SYS_user_free_page, (uint64)va, 0, 0, 0, 0, 0, 0); } // // lib call to naive_fork int fork() { return do_user_call(SYS_user_fork, 0, 0, 0, 0, 0, 0, 0); } // // lib call to yield // void yield() { do_user_call(SYS_user_yield, 0, 0, 0, 0, 0, 0, 0); } // // lib call to open // int open(const char *pathname, int flags) { return do_user_call(SYS_user_open, (uint64)pathname, flags, 0, 0, 0, 0, 0); } // // lib call to read // int read_u(int fd, void * buf, uint64 count){ return do_user_call(SYS_user_read, fd, (uint64)buf, count, 0, 0, 0, 0); } // // lib call to write // int write_u(int fd, void *buf, uint64 count) { return do_user_call(SYS_user_write, fd, (uint64)buf, count, 0, 0, 0, 0); } // // lib call to seek // int lseek_u(int fd, int offset, int whence) { return do_user_call(SYS_user_lseek, fd, offset, whence, 0, 0, 0, 0); } // // lib call to read file information // int stat_u(int fd, struct istat *istat) { return do_user_call(SYS_user_stat, fd, (uint64)istat, 0, 0, 0, 0, 0); } // // lib call to read file information from disk // int disk_stat_u(int fd, struct istat *istat) { return do_user_call(SYS_user_disk_stat, fd, (uint64)istat, 0, 0, 0, 0, 0); } // // lib call to close // int close(int fd) { return do_user_call(SYS_user_close, fd, 0, 0, 0, 0, 0, 0); }