From a87b65a2a9db3f2c1ddcb4cf7112020cbf103abf Mon Sep 17 00:00:00 2001
From: Davide <39653004+Tazdevil971@users.noreply.github.com>
Date: Sat, 16 Nov 2024 01:07:44 +0100
Subject: [PATCH] Add Mips64 N32 ABI (#743)

---
 src/common.rs           |  3 +++
 src/read/elf/file.rs    |  8 +++++++-
 src/write/elf/object.rs | 23 ++++++++++++++++-------
 tests/round_trip/mod.rs |  1 +
 4 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/common.rs b/src/common.rs
index 9f2bcc14..4edd9302 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -22,6 +22,8 @@ pub enum Architecture {
     M68k,
     Mips,
     Mips64,
+    #[allow(non_camel_case_types)]
+    Mips64_N32,
     Msp430,
     PowerPc,
     PowerPc64,
@@ -70,6 +72,7 @@ impl Architecture {
             Architecture::M68k => Some(AddressSize::U32),
             Architecture::Mips => Some(AddressSize::U32),
             Architecture::Mips64 => Some(AddressSize::U64),
+            Architecture::Mips64_N32 => Some(AddressSize::U32),
             Architecture::Msp430 => Some(AddressSize::U16),
             Architecture::PowerPc => Some(AddressSize::U32),
             Architecture::PowerPc64 => Some(AddressSize::U64),
diff --git a/src/read/elf/file.rs b/src/read/elf/file.rs
index ad5d9add..2c7e45bd 100644
--- a/src/read/elf/file.rs
+++ b/src/read/elf/file.rs
@@ -217,7 +217,13 @@ where
             (elf::EM_HEXAGON, _) => Architecture::Hexagon,
             (elf::EM_LOONGARCH, true) => Architecture::LoongArch64,
             (elf::EM_68K, false) => Architecture::M68k,
-            (elf::EM_MIPS, false) => Architecture::Mips,
+            (elf::EM_MIPS, false) => {
+                if (self.header.e_flags(self.endian) & elf::EF_MIPS_ABI2) != 0 {
+                    Architecture::Mips64_N32
+                } else {
+                    Architecture::Mips
+                }
+            }
             (elf::EM_MIPS, true) => Architecture::Mips64,
             (elf::EM_MSP430, _) => Architecture::Msp430,
             (elf::EM_PPC, _) => Architecture::PowerPc,
diff --git a/src/write/elf/object.rs b/src/write/elf/object.rs
index 1c2828e7..81a004f3 100644
--- a/src/write/elf/object.rs
+++ b/src/write/elf/object.rs
@@ -136,6 +136,7 @@ impl<'a> Object<'a> {
             Architecture::M68k => false,
             Architecture::Mips => false,
             Architecture::Mips64 => true,
+            Architecture::Mips64_N32 => true,
             Architecture::Msp430 => true,
             Architecture::PowerPc => true,
             Architecture::PowerPc64 => true,
@@ -276,12 +277,14 @@ impl<'a> Object<'a> {
                 (RelocationKind::PltRelative, _, 32) => elf::R_68K_PLT32,
                 _ => return unsupported_reloc(),
             },
-            Architecture::Mips | Architecture::Mips64 => match (kind, encoding, size) {
-                (K::Absolute, _, 16) => elf::R_MIPS_16,
-                (K::Absolute, _, 32) => elf::R_MIPS_32,
-                (K::Absolute, _, 64) => elf::R_MIPS_64,
-                _ => return unsupported_reloc(),
-            },
+            Architecture::Mips | Architecture::Mips64 | Architecture::Mips64_N32 => {
+                match (kind, encoding, size) {
+                    (K::Absolute, _, 16) => elf::R_MIPS_16,
+                    (K::Absolute, _, 32) => elf::R_MIPS_32,
+                    (K::Absolute, _, 64) => elf::R_MIPS_64,
+                    _ => return unsupported_reloc(),
+                }
+            }
             Architecture::Msp430 => match (kind, encoding, size) {
                 (K::Absolute, _, 32) => elf::R_MSP430_32,
                 (K::Absolute, _, 16) => elf::R_MSP430_16_BYTE,
@@ -562,6 +565,7 @@ impl<'a> Object<'a> {
             (Architecture::M68k, None) => elf::EM_68K,
             (Architecture::Mips, None) => elf::EM_MIPS,
             (Architecture::Mips64, None) => elf::EM_MIPS,
+            (Architecture::Mips64_N32, None) => elf::EM_MIPS,
             (Architecture::Msp430, None) => elf::EM_MSP430,
             (Architecture::PowerPc, None) => elf::EM_PPC,
             (Architecture::PowerPc64, None) => elf::EM_PPC64,
@@ -581,7 +585,7 @@ impl<'a> Object<'a> {
                 )));
             }
         };
-        let (os_abi, abi_version, e_flags) = if let FileFlags::Elf {
+        let (os_abi, abi_version, mut e_flags) = if let FileFlags::Elf {
             os_abi,
             abi_version,
             e_flags,
@@ -591,6 +595,11 @@ impl<'a> Object<'a> {
         } else {
             (elf::ELFOSABI_NONE, 0, 0)
         };
+
+        if self.architecture == Architecture::Mips64_N32 {
+            e_flags |= elf::EF_MIPS_ABI2;
+        }
+
         writer.write_file_header(&FileHeader {
             os_abi,
             abi_version,
diff --git a/tests/round_trip/mod.rs b/tests/round_trip/mod.rs
index bc61370e..91f3ce6d 100644
--- a/tests/round_trip/mod.rs
+++ b/tests/round_trip/mod.rs
@@ -275,6 +275,7 @@ fn elf_any() {
         (Architecture::M68k, Endianness::Big),
         (Architecture::Mips, Endianness::Little),
         (Architecture::Mips64, Endianness::Little),
+        (Architecture::Mips64_N32, Endianness::Little),
         (Architecture::Msp430, Endianness::Little),
         (Architecture::PowerPc, Endianness::Big),
         (Architecture::PowerPc64, Endianness::Big),