modules

core/Kconfig

@@ -0,0 +1,18 @@
+menu "Kernel Core options"
+
+source "core/mem/Kconfig"
+
+choice SCHED_ALG
+  prompt "Scheduler algorithm"
+  default SCHED_DUMB
+  help
+    The algorithm to use for scheduling.
+
+config SCHED_DUMB
+  bool "Dumb Scheduler"
+  help
+    Very basic scheduler, without any priorities.
+
+endchoice
+
+endmenu

core/mem/Kconfig

@@ -0,0 +1,8 @@
+menu "Memory Management options"
+
+config HAVE_MMU
+  bool
+config HAVE_MMU_GENERIC
+  bool
+
+endmenu

core/mem/meson.build

@@ -1,7 +1,6 @@
 kernel_sources += files(
     'fault.c',
     'init.c',
-    'pmap.c',
     'pmm.c',
     'slab.c',
     'usercopy.c',
@@ -9,3 +8,9 @@ kernel_sources += files(
     'vma.c',
     'vmo.c',
 )
+
+if kconfig.get('CONFIG_HAVE_MMU', 'n') == 'y'
+    kernel_sources += files(
+        'pmap.c',
+    )
+endif

core/mem/pmap.c

@@ -3,8 +3,12 @@
 #include <zinnia/pmap.h>
 #include <zinnia/spin.h>
 #include <zinnia/vma.h>
+#include <config.h>
 #include <string.h>
 
+// TODO: For now, we assume that we can do generic PTE lookups on every arch that has a MMU.
+static_assert(CONFIG_HAVE_MMU_GENERIC);
+
 errno_t pmap_new_kernel(struct pmap* pt, enum alloc_flags flags) {
     flags &= ~ALLOC_NOZERO;
 

core/mem/usercopy.c

@@ -3,13 +3,22 @@
 #include <arch/usercopy.h>
 
 bool usercopy_read(void* dst, const __user void* src, size_t len) {
-    return arch_usercopy_read(dst, src, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(true);
+    bool success = arch_usercopy_read(dst, src, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(false);
+    return success;
 }
 
 bool usercopy_write(__user void* dst, const void* src, size_t len) {
-    return arch_usercopy_write(dst, src, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(true);
+    bool success = arch_usercopy_write(dst, src, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(false);
+    return success;
 }
 
 bool usercopy_strlen(const __user char* str, size_t max, size_t* len) {
-    return arch_usercopy_strlen(str, max, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(true);
+    bool success = arch_usercopy_strlen(str, max, len, &percpu_get()->sched.current->usercopy_region);
+    arch_usercopy_allow(false);
+    return success;
 }

core/sched/meson.build

@@ -1,4 +1,7 @@
 kernel_sources += files(
     'core.c',
-    'sched_dumb.c',
 )
+
+if kconfig.get('CONFIG_SCHED_DUMB', 'n') == 'y'
+    kernel_sources += files('sched_dumb.c')
+endif