ptos: ps+hal: Add thread control block init

Signed-off-by: Chloe M <chloe@mensia.org>
2026-07-14 16:14:03 -04:00
parent fe6be93d32
commit fcfe1dfb4a
6 changed files with 168 additions and 2 deletions
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description: MD thread management
+ * Author:      Chloe M.
+ */
+
+#include <hal/thread.h>
+#include <hal/page.h>
+#include <ps/thread.h>
+#include <machine/gdt.h>
+#include <mm/vm.h>
+#include <string.h>
+
+/*
+ * Allocate a kernel stack for a thread
+ */
+static VOID *
+ThreadAllocKStack(VOID)
+{
+    MM_RANGE StackRange;
+    PT_STATUS Status;
+
+    Status = MmAllocatePages(1, &StackRange);
+    if (PT_ERROR(Status)) {
+        return NULL;
+    }
+
+    return RANGE_PTR(&StackRange);
+}
+
+/*
+ * Initialize a thread control block
+ *
+ * @Thread:  Thread to initialize TCB of
+ * @Tcb:     Thread control block to initialize
+ * @Ip:      Instruction pointer value to start off with
+ *
+ * TODO: Support user threads
+ */
+static PT_STATUS
+ThreadInitTcb(THREAD *Thread, TCB *Tcb, UPTR Ip)
+{
+    TRAP_FRAME *Frame;
+
+    if (Thread == NULL || Tcb == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    Thread->StackBase = (UPTR)ThreadAllocKStack();
+    if (Thread->StackBase == 0) {
+        return STATUS_NO_MEMORY;
+    }
+
+    /* Zero the whole frame */
+    Frame = &Tcb->FrameSnapshot;
+    RtlMemSet(Frame, 0, sizeof(*Frame));
+
+    /* Initialize only whats needed */
+    Frame->Rflags = 0x202;
+    Frame->Rsp = Thread->StackBase + PAGESIZE;
+    Frame->Rip = Ip;
+    Frame->CodeSeg = GDT_KCODE;
+    Frame->StackSeg = GDT_KDATA;
+    return STATUS_SUCCESS;
+}
+
+PT_STATUS
+HalThreadInit(THREAD *Thread, ULONG Flags, UPTR Ip)
+{
+    TCB *Tcb;
+
+    if (Thread == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    Tcb = &Thread->Tcb;
+    ThreadInitTcb(Thread, Tcb, Ip);
+    return STATUS_SUCCESS;
+}