Implement initSystem(), __ctru_exit() and __system_argc/argv

diff --git a/libctru/source/initSystem.c b/libctru/source/initSystem.c
new file mode 100644 (file)
index 0000000..1f51c03
--- /dev/null
+++ b/libctru/source/initSystem.c
@@ -0,0 +1,99 @@
+#include <sys/iosupport.h>
+#include <3ds/types.h>
+#include <3ds/svc.h>
+#include <string.h>
+
+// System globals we define here
+int __system_argc;
+char** __system_argv;
+void (*__system_retAddr)(void);
+
+// Data from _prm structure
+extern void* __service_ptr; // used to detect if we're run from a homebrew launcher
+extern u32 __heap_size;
+extern const char* __system_arglist;
+
+// newlib definitions we need
+void __libc_fini_array();
+extern char* fake_heap_start;
+extern char* fake_heap_end;
+
+static void initArgv();
+
+void __ctru_exit(int rc)
+{
+       // Run the global destructors
+       __libc_fini_array();
+
+       // TODO: APT exit goes here
+
+       // Unmap the heap
+       u32 blockAddr;
+       svcControlMemory(&blockAddr, 0x08000000, 0x0, __heap_size, MEMOP_FREE, 0x0);
+
+       // Jump to the loader if it provided a callback
+       if (__system_retAddr)
+               __system_retAddr();
+
+       // Since above did not jump: hang
+       for (;;);
+}
+
+void initSystem(void (*retAddr)(void))
+{
+       // Register newlib exit() syscall
+       __syscalls.exit = __ctru_exit;
+       __system_retAddr = __service_ptr ? retAddr : NULL;
+
+       // Allocate the application heap
+       u32 blockAddr;
+       svcControlMemory(&blockAddr, 0x08000000, 0x0, __heap_size, MEMOP_ALLOC, 0x3);
+
+       // Set up newlib heap
+       fake_heap_start = (char*)0x08000000;
+       fake_heap_end = fake_heap_start + __heap_size;
+
+       // Build argc/argv if present
+       initArgv();
+
+       // TODO: APT init goes here
+}
+
+void initArgv()
+{
+       int i;
+       const char* temp = __system_arglist;
+
+       // Check if the argument list is present
+       if (!temp)
+               return;
+
+       // Retrieve argc
+       __system_argc = *(u32*)temp;
+       temp += sizeof(u32);
+
+       // Find the end of the argument data
+       for (i = 0; i < __system_argc; i ++)
+       {
+               for (; *temp; temp ++);
+               temp ++;
+       }
+
+       // Reserve heap memory for argv data
+       u32 argSize = temp - __system_arglist - sizeof(u32);
+       __system_argv = (char**)fake_heap_start;
+       fake_heap_start += sizeof(char**)*(__system_argc + 1);
+       char* argCopy = fake_heap_start;
+       fake_heap_start += argSize;
+
+       // Fill argv array
+       memcpy(argCopy, __system_arglist, argSize);
+       temp = argCopy;
+       for (i = 0; i < __system_argc; i ++)
+       {
+               __system_argv[i] = (char*)temp;
+               for (; *temp; temp ++);
+               temp ++;
+       }
+       __system_argv[__system_argc] = NULL;
+}