--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/proc.h	Fri May 26 23:11:05 2017 +0900
@@ -0,0 +1,77 @@
+#ifndef PROC_INCLUDE_
+#define PROC_INCLUDE_
+
+// Per-CPU state, now we only support one CPU
+struct cpu {
+    uchar           id;             // index into cpus[] below
+    struct context*   scheduler;    // swtch() here to enter scheduler
+    volatile uint   started;        // Has the CPU started?
+
+    int             ncli;           // Depth of pushcli nesting.
+    int             intena;         // Were interrupts enabled before pushcli?
+
+    // Cpu-local storage variables; see below
+    struct cpu*     cpu;
+    struct proc*    proc;           // The currently-running process.
+};
+
+extern struct cpu cpus[NCPU];
+extern int ncpu;
+
+
+extern struct cpu* cpu;
+extern struct proc* proc;
+
+//PAGEBREAK: 17
+// Saved registers for kernel context switches. The context switcher
+// needs to save the callee save register, as usually. For ARM, it is
+// also necessary to save the banked sp (r13) and lr (r14) registers.
+// There is, however, no need to save the user space pc (r15) because
+// pc has been saved on the stack somewhere. We only include it here
+// for debugging purpose. It will not be restored for the next process.
+// According to ARM calling convension, r0-r3 is caller saved. We do
+// not need to save sp_svc, as it will be saved in the pcb, neither
+// pc_svc, as it will be always be the same value.
+//
+// Keep it in sync with swtch.S
+//
+struct context {
+    // svc mode registers
+    uint    r4;
+    uint    r5;
+    uint    r6;
+    uint    r7;
+    uint    r8;
+    uint    r9;
+    uint    r10;
+    uint    r11;
+    uint    r12;
+    uint    lr;
+};
+
+
+enum procstate { UNUSED, EMBRYO, SLEEPING, RUNNABLE, RUNNING, ZOMBIE };
+
+// Per-process state
+struct proc {
+    uint            sz;             // Size of process memory (bytes)
+    pde_t*          pgdir;          // Page table
+    char*           kstack;         // Bottom of kernel stack for this process
+    enum procstate  state;          // Process state
+    volatile int    pid;            // Process ID
+    struct proc*    parent;         // Parent process
+    struct trapframe*   tf;         // Trap frame for current syscall
+    struct context* context;        // swtch() here to run process
+    void*           chan;           // If non-zero, sleeping on chan
+    int             killed;         // If non-zero, have been killed
+    struct file*    ofile[NOFILE];  // Open files
+    struct inode*   cwd;            // Current directory
+    char            name[16];       // Process name (debugging)
+};
+
+// Process memory is laid out contiguously, low addresses first:
+//   text
+//   original data and bss
+//   fixed-size stack
+//   expandable heap
+#endif