From 80a90edd47d20141cfb7b18ededc9a3090fba58c Mon Sep 17 00:00:00 2001 From: Sergey 'Jin' Bostandzhyan Date: Fri, 4 Jan 2013 02:29:03 +0100 Subject: Work around MEMERASE ioctl for rk3066 compatibility Due to a kernel bug and no available sources we have to work around the MEMERASE ioctl - if used, it hangs and never returns. I straced the original recovery executable and could see that it is simply calling write() with a bunch of zeroes instead of using MEMERASE. Added a hack that does the same and now the resulting TWRP recovery image works. Change-Id: I1b1c1c9e870e350776346bdca5d442c7ef565aa0 --- mtdutils/rk30hack.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 mtdutils/rk30hack.h (limited to 'mtdutils/rk30hack.h') diff --git a/mtdutils/rk30hack.h b/mtdutils/rk30hack.h new file mode 100644 index 000000000..d492793ff --- /dev/null +++ b/mtdutils/rk30hack.h @@ -0,0 +1,37 @@ +/* + * Copyright (c) 2013 Sergey 'Jin' Bostandzhyan + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* This is a hack for Rockchip rk30xx based devices. The problem is that + * the MEMERASE ioctl is failing (hangs and never returns) in their kernel. + * The sources are not fully available, so fixing it in the rk30xxnand_ko driver + * is not possible. + * + * I straced the stock recovery application and it seems to avoid this + * particular ioctl, instead it is simply writing zeroes using the write() call. + * + * This workaround does the same and will replace all MEMERASE occurances in + * the recovery code. + */ + +#ifndef __RK30_HACK_H__ +#define __RK30_HACK_H__ + +#include // for size_t, etc. + +// write zeroes to fd at position pos +int zero_out(int fd, off_t pos, ssize_t length); + +#endif//__RK30_HACK_H__ -- cgit v1.2.3