rpc_gateway_exports.h

00001 /*
00002  * Copyright (c) 2016, ARM Limited, All Rights Reserved
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License"); you may
00006  * not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  * http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00013  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 #ifndef __UVISOR_API_RPC_GATEWAY_EXPORTS_H__
00018 #define __UVISOR_API_RPC_GATEWAY_EXPORTS_H__
00019 
00020 #include "api/inc/uvisor_exports.h"
00021 #include "api/inc/magic_exports.h"
00022 #include <stdint.h>
00023 
00024 /* ldr pc, [pc, #<label - instr + 4>]
00025  * LDR (immediate) - ARMv7M ARM section A7.7.42
00026  * 1111;1 00 0; 0 10 1; <Rn - 1111>; <Rt - 1111>; <imm12> (Encoding T3) */
00027 #define LDR_PC_PC_IMM_OPCODE(instr, label) \
00028     ((uint32_t) (0xF000F8DFUL | ((((uint32_t) (label) - ((uint32_t) (instr) + 4)) & 0xFFFUL) << 16)))
00029 
00030 /** RPC gateway structure
00031  *
00032  * This struct is packed because we must ensure that the `ldr_pc` field has no
00033  * padding before itself and will be located at a valid instruction location,
00034  * and that the `caller` and `target` field are at a pre-determined offset from
00035  * the `ldr_pc` field.
00036  */
00037 typedef struct RPCGateway {
00038     uint32_t ldr_pc;
00039     uint32_t magic;
00040     uint32_t box_ptr;
00041     uint32_t target;
00042     uint32_t caller; /* This is not for use by anything other than the ldr_pc. It's like a pretend literal pool. */
00043 } UVISOR_PACKED UVISOR_ALIGN(4) TRPCGateway;
00044 
00045 #endif /* __UVISOR_API_RPC_GATEWAY_EXPORTS_H__ */