github.com/transparency-dev/armored-witness-os@v0.1.3-0.20240514084412-27eef7325168/trusted_os/mem_bee.go (about) 1 // Copyright 2022 The Armored Witness OS authors. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 //go:build bee 16 // +build bee 17 18 package main 19 20 import ( 21 _ "unsafe" 22 ) 23 24 // The following memory regions are within an alias of external DDR, required 25 // when memory encryption is enforced by the i.MX6UL Bus Encryption Engine 26 // (BEE). 27 const ( 28 // The Secure Monitor RAM cannot be used as reserved area for 29 // arm.Init() as the L1/L2 page tables cannot be placed in BEE aliased 30 // memory due to its caching requirements, we therefore override 31 // vecTableStart with the alias physical pointer. 32 physicalStart = 0x80000000 // imx6ul.MMDC_BASE 33 34 // Secure Monitor DMA 35 // 36 // BEE aliased regions must be accessed either through cache or 16 byte 37 // accesses, this makes it impractical for peripheral driver DMA use 38 // and we must therefore keep DMA on a non-aliased region. 39 secureDMAStart = 0x8e000000 40 secureDMASize = 0x02000000 // 32MB 41 42 // Secure Monitor 43 secureStart = 0x10000000 // bee.AliasRegion0 44 secureSize = 0x0e000000 // 224MB 45 46 // Secure Monitor Applet 47 appletStart = 0x20000000 48 appletSize = 0x10000000 // 256MB 49 ) 50 51 //go:linkname ramStart runtime.ramStart 52 var ramStart uint32 = secureStart 53 54 //go:linkname ramSize runtime.ramSize 55 var ramSize uint32 = secureSize 56 57 //go:linkname vecTableStart github.com/usbarmory/tamago/arm.vecTableStart 58 var vecTableStart uint32 = physicalStart