From 9f91ba1f7357c61dd2c7c3b437ea203d467fd400 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Fri, 17 Nov 2023 23:44:53 +0200
Subject: arm: Implement native code execution backend

---
 src/core/arm/nce/instructions.h | 147 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 147 insertions(+)
 create mode 100644 src/core/arm/nce/instructions.h

(limited to 'src/core/arm/nce/instructions.h')

diff --git a/src/core/arm/nce/instructions.h b/src/core/arm/nce/instructions.h
new file mode 100644
index 000000000..5b56ff857
--- /dev/null
+++ b/src/core/arm/nce/instructions.h
@@ -0,0 +1,147 @@
+// SPDX-FileCopyrightText: Copyright © 2020 Skyline Team and Contributors
+// SPDX-License-Identifier: MPL-2.0
+
+#include "common/bit_field.h"
+#include "common/common_types.h"
+
+namespace Core::NCE {
+
+enum SystemRegister : u32 {
+    TpidrEl0 = 0x5E82,
+    TpidrroEl0 = 0x5E83,
+    CntfrqEl0 = 0x5F00,
+    CntpctEl0 = 0x5F01,
+};
+
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/SVC--Supervisor-Call-
+union SVC {
+    constexpr explicit SVC(u32 raw_) : raw{raw_} {}
+
+    constexpr bool Verify() {
+        return (this->GetSig0() == 0x1 && this->GetSig1() == 0x6A0);
+    }
+
+    constexpr u32 GetSig0() {
+        return decltype(sig0)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetValue() {
+        return decltype(value)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetSig1() {
+        return decltype(sig1)::ExtractValue(raw);
+    }
+
+    u32 raw;
+
+private:
+    BitField<0, 5, u32> sig0;   // 0x1
+    BitField<5, 16, u32> value; // 16-bit immediate
+    BitField<21, 11, u32> sig1; // 0x6A0
+};
+static_assert(sizeof(SVC) == sizeof(u32));
+static_assert(SVC(0xD40000C1).Verify());
+static_assert(SVC(0xD40000C1).GetValue() == 0x6);
+
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/MRS--Move-System-Register-
+union MRS {
+    constexpr explicit MRS(u32 raw_) : raw{raw_} {}
+
+    constexpr bool Verify() {
+        return (this->GetSig() == 0xD53);
+    }
+
+    constexpr u32 GetRt() {
+        return decltype(rt)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetSystemReg() {
+        return decltype(system_reg)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetSig() {
+        return decltype(sig)::ExtractValue(raw);
+    }
+
+    u32 raw;
+
+private:
+    BitField<0, 5, u32> rt;          // destination register
+    BitField<5, 15, u32> system_reg; // source system register
+    BitField<20, 12, u32> sig;       // 0xD53
+};
+static_assert(sizeof(MRS) == sizeof(u32));
+static_assert(MRS(0xD53BE020).Verify());
+static_assert(MRS(0xD53BE020).GetSystemReg() == CntpctEl0);
+static_assert(MRS(0xD53BE020).GetRt() == 0x0);
+
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/MSR--register---Move-general-purpose-register-to-System-Register-
+union MSR {
+    constexpr explicit MSR(u32 raw_) : raw{raw_} {}
+
+    constexpr bool Verify() {
+        return this->GetSig() == 0xD51;
+    }
+
+    constexpr u32 GetRt() {
+        return decltype(rt)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetSystemReg() {
+        return decltype(system_reg)::ExtractValue(raw);
+    }
+
+    constexpr u32 GetSig() {
+        return decltype(sig)::ExtractValue(raw);
+    }
+
+    u32 raw;
+
+private:
+    BitField<0, 5, u32> rt;          // source register
+    BitField<5, 15, u32> system_reg; // destination system register
+    BitField<20, 12, u32> sig;       // 0xD51
+};
+static_assert(sizeof(MSR) == sizeof(u32));
+static_assert(MSR(0xD51BD040).Verify());
+static_assert(MSR(0xD51BD040).GetSystemReg() == TpidrEl0);
+static_assert(MSR(0xD51BD040).GetRt() == 0x0);
+
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/LDXR--Load-Exclusive-Register-
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/LDXP--Load-Exclusive-Pair-of-Registers-
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/STXR--Store-Exclusive-Register-
+// https://developer.arm.com/documentation/ddi0596/2021-12/Base-Instructions/STXP--Store-Exclusive-Pair-of-registers-
+union Exclusive {
+    constexpr explicit Exclusive(u32 raw_) : raw{raw_} {}
+
+    constexpr bool Verify() {
+        return this->GetSig() == 0x10;
+    }
+
+    constexpr u32 GetSig() {
+        return decltype(sig)::ExtractValue(raw);
+    }
+
+    constexpr u32 AsOrdered() {
+        return raw | decltype(o0)::FormatValue(1);
+    }
+
+    u32 raw;
+
+private:
+    BitField<0, 5, u32> rt;    // memory operand
+    BitField<5, 5, u32> rn;    // register operand 1
+    BitField<10, 5, u32> rt2;  // register operand 2
+    BitField<15, 1, u32> o0;   // ordered
+    BitField<16, 5, u32> rs;   // status register
+    BitField<21, 2, u32> l;    // operation type
+    BitField<23, 7, u32> sig;  // 0x10
+    BitField<30, 2, u32> size; // size
+};
+static_assert(Exclusive(0xC85FFC00).Verify());
+static_assert(Exclusive(0xC85FFC00).AsOrdered() == 0xC85FFC00);
+static_assert(Exclusive(0xC85F7C00).AsOrdered() == 0xC85FFC00);
+static_assert(Exclusive(0xC8200440).AsOrdered() == 0xC8208440);
+
+} // namespace Core::NCE
-- 
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