From 4b67fd46956d837dc2d8dbdeab0f2482984bffec Mon Sep 17 00:00:00 2001
From: pjht <pterpstra@pterpstra.com>
Date: Tue, 19 Mar 2024 13:09:43 -0500
Subject: [PATCH] Add support for processes setting up an address space to
 spawn new processes

---
 syscalls.68k | 12 ++++++++++++
 tasking.68k  |  8 ++++++++
 tasking.i    |  2 ++
 3 files changed, 22 insertions(+)

diff --git a/syscalls.68k b/syscalls.68k
index 80ca99b..eb2cafd 100644
--- a/syscalls.68k
+++ b/syscalls.68k
@@ -62,6 +62,17 @@ syscall_vmem_set_flags:
   move.l #0, d2
   jmp vmem_set_flags
 
+; Copies the range of page mappings at address a0 in the primary space with length d1 to the secondary space starting at address a1
+syscall_vmem_copy_to_secondary:
+  movem.l a0/a1/d1, -(a7)
+  jsr tasking_get_secondary_addr_space
+  jsr vmem_set_secondary_addr_space
+  movem.l (a7)+, a0/a1/d1
+  move.l d1, d0
+  jsr vmem_copy_to_secondary
+  rts
+
+
   section .data,data
 syscall_table:
   align 1
@@ -73,3 +84,4 @@ syscall_table:
   dc.l syscall_vmem_map_free
   dc.l syscall_vmem_map_free_to
   dc.l syscall_vmem_set_flags
+  dc.l syscall_vmem_copy_to_secondary
diff --git a/tasking.68k b/tasking.68k
index b01d704..a084206 100644
--- a/tasking.68k
+++ b/tasking.68k
@@ -4,6 +4,7 @@ task.stack_frame: so.l 1
 task.stack_ptr: so.l 1
 task.next_ptr: so.l 1
 task.address_space: so.l 4
+task.secondary_address_space: so.l 4
 task.sizeof equ __SO
 
   include term.i
@@ -176,6 +177,13 @@ tasking_exit:
   movem.l (a7)+, d2-d7/a2-a6
   rts
 
+; Gets the secondary address space of the current process in a0
+  public tasking_get_secondary_addr_space
+tasking_get_secondary_addr_space:
+  move.l current_process, a0
+  lea.l (task.secondary_address_space,a0), a0
+  rts
+
 ; Push the process pointed to by a0 onto the head of the ready to run list
 rtr_push_head:
   cmp.l #0, ready_to_run_head
diff --git a/tasking.i b/tasking.i
index f0373aa..fa9ab14 100644
--- a/tasking.i
+++ b/tasking.i
@@ -10,4 +10,6 @@ TASKING_I equ 1
   xref tasking_yield
 ; Exits the current process
   xref tasking_exit
+; Gets the secondary address space of the current process in a0
+  xref tasking_get_secondary_addr_space
   endif