Move threading calls into a basic user space library.

lib/mammoth/CMakeLists.txt

@@ -0,0 +1,16 @@
+add_library(mammoth_lib STATIC
+  src/debug.cpp
+  src/thread.cpp
+  )
+
+target_include_directories(mammoth_lib
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+
+target_link_libraries(mammoth_lib
+  zion_lib)
+
+set(_COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -c -ffreestanding -fno-rtti -fno-exceptions -nostdlib -mabi=sysv -mgeneral-regs-only")
+
+set_target_properties(mammoth_lib PROPERTIES
+  COMPILE_FLAGS "${_COMPILE_FLAGS}")

lib/mammoth/include/mammoth/debug.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void dbgln(const char*);

lib/mammoth/include/mammoth/thread.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stdint.h>
+
+class Thread {
+ public:
+  typedef void (*Entry)(void*);
+
+  Thread(Entry e, const void* arg1);
+
+ private:
+  uint64_t thread_cap_;
+};

lib/mammoth/src/debug.cpp

@@ -0,0 +1,5 @@
+#include "include/mammoth/debug.h"
+
+#include "zcall.h"
+
+void dbgln(const char* str) { ZDebug(str); }

lib/mammoth/src/thread.cpp

@@ -0,0 +1,19 @@
+#include "include/mammoth/thread.h"
+
+#include "zcall.h"
+
+namespace {
+
+extern "C" void thread_entry(Thread::Entry entry, void* arg1) {
+  entry(arg1);
+
+  ZThreadExit();
+}
+
+}  // namespace
+
+Thread::Thread(Entry e, const void* arg1) {
+  ZThreadCreate(Z_INIT_PROC_SELF, &thread_cap_);
+  ZThreadStart(thread_cap_, reinterpret_cast<uint64_t>(thread_entry),
+               reinterpret_cast<uint64_t>(e), reinterpret_cast<uint64_t>(arg1));
+}