Stage 5

clks/kernel/syscall.c

@@ -0,0 +1,102 @@
+#include <clks/interrupts.h>
+#include <clks/log.h>
+#include <clks/scheduler.h>
+#include <clks/syscall.h>
+#include <clks/types.h>
+
+struct clks_syscall_frame {
+    u64 rax;
+    u64 rbx;
+    u64 rcx;
+    u64 rdx;
+    u64 rsi;
+    u64 rdi;
+    u64 rbp;
+    u64 r8;
+    u64 r9;
+    u64 r10;
+    u64 r11;
+    u64 r12;
+    u64 r13;
+    u64 r14;
+    u64 r15;
+    u64 vector;
+    u64 error_code;
+    u64 rip;
+    u64 cs;
+    u64 rflags;
+    u64 rsp;
+    u64 ss;
+};
+
+static clks_bool clks_syscall_ready = CLKS_FALSE;
+
+static u64 clks_syscall_log_write(u64 arg0, u64 arg1) {
+    const char *src = (const char *)arg0;
+    u64 len = arg1;
+    char buf[192];
+    u64 i;
+
+    if (src == CLKS_NULL || len == 0ULL) {
+        return 0ULL;
+    }
+
+    if (len > (sizeof(buf) - 1U)) {
+        len = sizeof(buf) - 1U;
+    }
+
+    for (i = 0; i < len; i++) {
+        buf[i] = src[i];
+    }
+
+    buf[len] = '\0';
+    clks_log(CLKS_LOG_INFO, "SYSCALL", buf);
+
+    return len;
+}
+
+void clks_syscall_init(void) {
+    clks_syscall_ready = CLKS_TRUE;
+    clks_log(CLKS_LOG_INFO, "SYSCALL", "INT80 FRAMEWORK ONLINE");
+}
+
+u64 clks_syscall_dispatch(void *frame_ptr) {
+    struct clks_syscall_frame *frame = (struct clks_syscall_frame *)frame_ptr;
+    u64 id;
+
+    if (clks_syscall_ready == CLKS_FALSE || frame == CLKS_NULL) {
+        return (u64)-1;
+    }
+
+    id = frame->rax;
+
+    switch (id) {
+        case CLKS_SYSCALL_LOG_WRITE:
+            return clks_syscall_log_write(frame->rbx, frame->rcx);
+        case CLKS_SYSCALL_TIMER_TICKS:
+            return clks_interrupts_timer_ticks();
+        case CLKS_SYSCALL_TASK_COUNT: {
+            struct clks_scheduler_stats stats = clks_scheduler_get_stats();
+            return stats.task_count;
+        }
+        case CLKS_SYSCALL_CURRENT_TASK_ID: {
+            struct clks_scheduler_stats stats = clks_scheduler_get_stats();
+            return stats.current_task_id;
+        }
+        default:
+            return (u64)-1;
+    }
+}
+
+u64 clks_syscall_invoke_kernel(u64 id, u64 arg0, u64 arg1, u64 arg2) {
+    u64 ret;
+
+    __asm__ volatile(
+        "int $0x80"
+        : "=a"(ret)
+        : "a"(id), "b"(arg0), "c"(arg1), "d"(arg2)
+        : "memory"
+    );
+
+    return ret;
+}