lib/syscall.c

   1 // System call stubs.
   2
   3 #include <inc/syscall.h>
   4 #include <inc/lib.h>
   5
   6 static inline int32_t
   7 syscall(int num, int check, uint32_t a1, uint32_t a2, uint32_t a3, uint32_t a4, uint32_t a5)
   8 {
   9         int32_t ret;
  10
  11         // Generic system call: pass system call number in AX,
  12         // up to five parameters in DX, CX, BX, DI, SI.
  13         // Interrupt kernel with T_SYSCALL.
  14         //
  15         // The "volatile" tells the assembler not to optimize
  16         // this instruction away just because we don't use the
  17         // return value.
  18         //
  19         // The last clause tells the assembler that this can
  20         // potentially change the condition codes and arbitrary
  21         // memory locations.
  22
  23         asm volatile("int %1\n"
  24                 : "=a" (ret)
  25                 : "i" (T_SYSCALL),
  26                   "a" (num),
  27                   "d" (a1),
  28                   "c" (a2),
  29                   "b" (a3),
  30                   "D" (a4),
  31                   "S" (a5)
  32                 : "cc", "memory");
  33
  34         if(check && ret > 0)
  35                 panic("syscall %d returned %d (> 0)", num, ret);
  36
  37         return ret;
  38 }
  39
  40 void
  41 sys_cputs(const char *s, size_t len)
  42 {
  43         syscall(SYS_cputs, 0, (uint32_t)s, len, 0, 0, 0);
  44 }
  45
  46 int
  47 sys_cgetc(void)
  48 {
  49         return syscall(SYS_cgetc, 0, 0, 0, 0, 0, 0);
  50 }
  51
  52 int
  53 sys_env_destroy(envid_t envid)
  54 {
  55         return syscall(SYS_env_destroy, 1, envid, 0, 0, 0, 0);
  56 }
  57
  58 envid_t
  59 sys_getenvid(void)
  60 {
  61          return syscall(SYS_getenvid, 0, 0, 0, 0, 0, 0);
  62 }
  63
  64 void
  65 sys_yield(void)
  66 {
  67         syscall(SYS_yield, 0, 0, 0, 0, 0, 0);
  68 }
  69
  70 int
  71 sys_page_alloc(envid_t envid, void *va, int perm)
  72 {
  73         return syscall(SYS_page_alloc, 1, envid, (uint32_t) va, perm, 0, 0);
  74 }
  75
  76 int
  77 sys_page_map(envid_t srcenv, void *srcva, envid_t dstenv, void *dstva, int perm)
  78 {
  79         return syscall(SYS_page_map, 1, srcenv, (uint32_t) srcva, dstenv, (uint32_t) dstva, perm);
  80 }
  81
  82 int
  83 sys_page_unmap(envid_t envid, void *va)
  84 {
  85         return syscall(SYS_page_unmap, 1, envid, (uint32_t) va, 0, 0, 0);
  86 }
  87
  88 // sys_exofork is inlined in lib.h
  89
  90 int
  91 sys_env_set_status(envid_t envid, int status)
  92 {
  93         return syscall(SYS_env_set_status, 1, envid, status, 0, 0, 0);
  94 }
  95
  96 int
  97 sys_env_set_trapframe(envid_t envid, struct Trapframe *tf)
  98 {
  99         return syscall(SYS_env_set_trapframe, 1, envid, (uint32_t) tf, 0, 0, 0);
 100 }
 101
 102 int
 103 sys_env_set_pgfault_upcall(envid_t envid, void *upcall)
 104 {
 105         return syscall(SYS_env_set_pgfault_upcall, 1, envid, (uint32_t) upcall, 0, 0, 0);
 106 }
 107
 108 int
 109 sys_ipc_try_send(envid_t envid, uint32_t value, void *srcva, int perm)
 110 {
 111         return syscall(SYS_ipc_try_send, 0, envid, value, (uint32_t) srcva, perm, 0);
 112 }
 113
 114 int
 115 sys_ipc_recv(void *dstva)
 116 {
 117         return syscall(SYS_ipc_recv, 1, (uint32_t)dstva, 0, 0, 0, 0);
 118 }
 119
 120 int
 121 sys_phy_page(envid_t envid, void *va)
 122 {
 123         return syscall(SYS_phy_page, 0, (uint32_t)envid, (uint32_t)va, 0, 0, 0);
 124 }