Primitive ability to call kernel code from userspace.

4 files changed, 40 insertions, 1 deletions

diff --git a/include/kern/mpu/mpu_manager.h b/include/kern/mpu/mpu_manager.h
index 7c47722..5a0904c 100644
--- a/include/kern/mpu/mpu_manager.h
+++ b/include/kern/mpu/mpu_manager.h
@@ -55,7 +55,7 @@ typedef enum {
 
   /* Both privileged and non-privileged users can access this memory, but only
      as Read-only.*/
-  ACCESS_PERMS_BOTH_RO = 5,
+  ACCESS_PERMS_BOTH_RO = 6,
 } access_perms_t;
 
 typedef struct {
@@ -81,4 +81,28 @@ void mpu_set_enabled(bool enabled);
  */
 void mpu_configure_region(int region_number, memory_region_opts_t* opts);
 
+typedef enum {
+  PRIVILEGED,
+  NOT_PRIVILEGED,
+} privilege_t;
+
+
+/** Configure a peripheral region with default peripheral attributes. */
+void configure_peripheral_region(
+    void* peripheral_base,
+    region_size_t region_size,
+    privilege_t priv);
+
+/** Configure a flash region with default flash attributes. */
+void configure_flash_region(
+    void* flash_base,
+    region_size_t region_size,
+    privilege_t priv);
+
+/** Configure a ram region with default ram attributes. */
+void configure_ram_region(
+    void* ram_base,
+    region_size_t region_size,
+    privilege_t priv);
+
 #endif /* KERN_MPU_MPU_MANAGER_H_ */
diff --git a/include/kern/priv.h b/include/kern/priv.h
index 8940b23..35404f4 100644
--- a/include/kern/priv.h
+++ b/include/kern/priv.h
@@ -10,5 +10,7 @@ void set_control_register(uint32_t reg);
 /* Enters user mode from privilieged mode. */
 void enter_user_mode();
 
+void jump_to_user_mode();
+
 
 #endif /* _KERN_PRIV_H_ */
diff --git a/include/kern/syscall.h b/include/kern/syscall.h
new file mode 100644
index 0000000..d39b620
--- /dev/null
+++ b/include/kern/syscall.h
@@ -0,0 +1,8 @@
+#ifndef KERN_SYSCALL_H_
+#define KERN_SYSCALL_H_
+
+#define SYSCALL(id, fn, kernfn, argt) void kernfn(argt arg);
+#include "kern/syscall/syscall_tbl.inc"
+#undef SYSCALL
+
+#endif
diff --git a/include/kern/syscall/syscall_tbl.inc b/include/kern/syscall/syscall_tbl.inc
new file mode 100644
index 0000000..6c4be57
--- /dev/null
+++ b/include/kern/syscall/syscall_tbl.inc
@@ -0,0 +1,5 @@
+/*
+ * Defines a table of SYSCALLS. The syscalls need to be void functions that
+ * a single 32-bit integer as their argument.
+ */
+SYSCALL(25, logs, kern_logs, const char*)