/********************************************************/
/*  ntapi: Native API core library                      */
/*  Copyright (C) 2013--2017  Z. Gilboa                 */
/*  Released under GPLv2 and GPLv3; see COPYING.NTAPI.  */
/********************************************************/

#include <psxtypes/psxtypes.h>
#include <ntapi/nt_ldr.h>
#include <ntapi/ntapi.h>
#include "ntapi_impl.h"

int32_t	__stdcall __ntapi_ldr_load_system_dll(
	__in	void *			hsysdir		__optional,
	__in	wchar16_t *		base_name,
	__in	uint16_t		base_name_size,
	__in	uint32_t *		image_flags	__optional,
	__out	void **			image_base)
{
	int32_t			status;
	wchar16_t *		wch;
	wchar16_t *		sysdir;
	nt_unicode_string	nt_sysdir;
	nt_unicode_string	nt_image_name;
	uintptr_t		buffer[0x80];

	(void)image_flags;

	/* stack buffer */
	__ntapi->tt_aligned_block_memset(
		buffer,0,sizeof(buffer));

	sysdir = (wchar16_t *)buffer;

	/* shell-style dos path */
	if ((status = __ntapi->tt_get_system_directory_dos_path(
			hsysdir,
			sysdir,sizeof(buffer),
			0,0,&nt_sysdir)))
		return status;

	sysdir = &sysdir[4];

	/* image */
	nt_image_name.strlen = base_name_size;
	nt_image_name.maxlen = base_name_size;
	nt_image_name.buffer = base_name;

	status = __ntapi->ldr_load_dll(
		sysdir,0,
		&nt_image_name,
		image_base);

	switch (status) {
		case NT_STATUS_DLL_NOT_FOUND:
			break;

		default:
			return status;
	}

	/* downlevel */
	for (wch=sysdir; *wch; wch++)
		(void)0;

	if (&wch[10] > &sysdir[sizeof(buffer)/sizeof(wchar16_t)])
		return NT_STATUS_BUFFER_TOO_SMALL;

	*wch++ = 'd';
	*wch++ = 'o';
	*wch++ = 'w';
	*wch++ = 'n';
	*wch++ = 'l';
	*wch++ = 'e';
	*wch++ = 'v';
	*wch++ = 'e';
	*wch++ = 'l';
	*wch++ = '\\';
	*wch++ = 0;

	return __ntapi->ldr_load_dll(
		sysdir,0,
		&nt_image_name,
		image_base);
}