elf: add basic support for E2K arch (#727)

Author: numas13

src/common.rs

@@ -11,6 +11,8 @@ pub enum Architecture {
     Avr,
     Bpf,
     Csky,
+    E2K32,
+    E2K64,
     I386,
     X86_64,
     #[allow(non_camel_case_types)]
@@ -57,6 +59,8 @@ impl Architecture {
             Architecture::Avr => Some(AddressSize::U8),
             Architecture::Bpf => Some(AddressSize::U64),
             Architecture::Csky => Some(AddressSize::U32),
+            Architecture::E2K32 => Some(AddressSize::U32),
+            Architecture::E2K64 => Some(AddressSize::U64),
             Architecture::I386 => Some(AddressSize::U32),
             Architecture::X86_64 => Some(AddressSize::U64),
             Architecture::X86_64_X32 => Some(AddressSize::U32),
@@ -415,6 +419,18 @@ pub enum RelocationEncoding {
     /// * 16-bit absolute address
     /// * 6-bit relative address
     SharcTypeB,
+
+    /// E2K 64-bit value stored in two LTS
+    ///
+    /// Memory representation:
+    /// ```text
+    /// 0: LTS1 = value[63:32]
+    /// 4: LTS0 = value[31:0]
+    /// ```
+    E2KLit,
+
+    /// E2K 28-bit value stored in CS0
+    E2KDisp,
 }
 
 /// File flags that are specific to each file format.

src/elf.rs

@@ -6270,6 +6270,172 @@ pub const R_XTENSA_NDIFF8: u32 = 60;
 pub const R_XTENSA_NDIFF16: u32 = 61;
 pub const R_XTENSA_NDIFF32: u32 = 62;
 
+// E2K values for `FileHeader*::e_flags`.
+pub const EF_E2K_IPD: u32 = 3;
+pub const EF_E2K_X86APP: u32 = 4;
+pub const EF_E2K_4MB_PAGES: u32 = 8;
+pub const EF_E2K_INCOMPAT: u32 = 16;
+pub const EF_E2K_PM: u32 = 32;
+pub const EF_E2K_PACK_SEGMENTS: u32 = 64;
+
+/// Encode `E_E2K_MACH_*` into `FileHeader*::e_flags`.
+pub const fn ef_e2k_mach_to_flag(e_flags: u32, x: u32) -> u32 {
+    (e_flags & 0xffffff) | (x << 24)
+}
+
+/// Decode `E_E2K_MACH_*` from `FileHeader*::e_flags`.
+pub const fn ef_e2k_flag_to_mach(e_flags: u32) -> u32 {
+    e_flags >> 24
+}
+
+// Codes of supported E2K machines.
+
+/// -march=generic code.
+///
+/// Legacy. Shouldn't be created nowadays.
+pub const E_E2K_MACH_BASE: u32 = 0;
+/// -march=elbrus-v1 code.
+///
+/// Legacy. Shouldn't be created nowadays.
+pub const E_E2K_MACH_EV1: u32 = 1;
+/// -march=elbrus-v2 code.
+pub const E_E2K_MACH_EV2: u32 = 2;
+/// -march=elbrus-v3 code.
+pub const E_E2K_MACH_EV3: u32 = 3;
+/// -march=elbrus-v4 code.
+pub const E_E2K_MACH_EV4: u32 = 4;
+/// -march=elbrus-v5 code.
+pub const E_E2K_MACH_EV5: u32 = 5;
+/// -march=elbrus-v6 code.
+pub const E_E2K_MACH_EV6: u32 = 6;
+/// -march=elbrus-v7 code.
+pub const E_E2K_MACH_EV7: u32 = 7;
+/// -mtune=elbrus-8c code.
+pub const E_E2K_MACH_8C: u32 = 19;
+/// -mtune=elbrus-1c+ code.
+pub const E_E2K_MACH_1CPLUS: u32 = 20;
+/// -mtune=elbrus-12c code.
+pub const E_E2K_MACH_12C: u32 = 21;
+/// -mtune=elbrus-16c code.
+pub const E_E2K_MACH_16C: u32 = 22;
+/// -mtune=elbrus-2c3 code.
+pub const E_E2K_MACH_2C3: u32 = 23;
+/// -mtune=elbrus-48c code.
+pub const E_E2K_MACH_48C: u32 = 24;
+/// -mtune=elbrus-8v7 code.
+pub const E_E2K_MACH_8V7: u32 = 25;
+
+// E2K values `Rel*::r_type`.
+
+/// Direct 32 bit.
+pub const R_E2K_32_ABS: u32 = 0;
+/// PC relative 32 bit.
+pub const R_E2K_32_PC: u32 = 2;
+/// 32-bit offset of AP GOT entry.
+pub const R_E2K_AP_GOT: u32 = 3;
+/// 32-bit offset of PL GOT entry.
+pub const R_E2K_PL_GOT: u32 = 4;
+/// Create PLT entry.
+pub const R_E2K_32_JMP_SLOT: u32 = 8;
+/// Copy relocation, 32-bit case.
+pub const R_E2K_32_COPY: u32 = 9;
+/// Adjust by program base, 32-bit case.
+pub const R_E2K_32_RELATIVE: u32 = 10;
+/// Adjust indirectly by program base, 32-bit case.
+pub const R_E2K_32_IRELATIVE: u32 = 11;
+/// Size of symbol plus 32-bit addend.
+pub const R_E2K_32_SIZE: u32 = 12;
+/// Symbol value if resolved by the definition in the same
+/// compilation unit or NULL otherwise, 32-bit case.
+pub const R_E2K_32_DYNOPT: u32 = 13;
+/// Direct 64 bit.
+pub const R_E2K_64_ABS: u32 = 50;
+/// Direct 64 bit for literal.
+pub const R_E2K_64_ABS_LIT: u32 = 51;
+/// PC relative 64 bit for literal.
+pub const R_E2K_64_PC_LIT: u32 = 54;
+/// Create PLT entry, 64-bit case.
+pub const R_E2K_64_JMP_SLOT: u32 = 63;
+/// Copy relocation, 64-bit case.
+pub const R_E2K_64_COPY: u32 = 64;
+/// Adjust by program base, 64-bit case.
+pub const R_E2K_64_RELATIVE: u32 = 65;
+/// Adjust by program base for literal, 64-bit case.
+pub const R_E2K_64_RELATIVE_LIT: u32 = 66;
+/// Adjust indirectly by program base, 64-bit case.
+pub const R_E2K_64_IRELATIVE: u32 = 67;
+/// Size of symbol plus 64-bit addend.
+pub const R_E2K_64_SIZE: u32 = 68;
+/// 64-bit offset of the symbol from GOT.
+pub const R_E2K_64_GOTOFF: u32 = 69;
+
+/// GOT entry for ID of module containing symbol.
+pub const R_E2K_TLS_GDMOD: u32 = 70;
+/// GOT entry for offset in module TLS block.
+pub const R_E2K_TLS_GDREL: u32 = 71;
+/// Static TLS block offset GOT entry.
+pub const R_E2K_TLS_IE: u32 = 74;
+/// Offset relative to static TLS block, 32-bit case.
+pub const R_E2K_32_TLS_LE: u32 = 75;
+/// Offset relative to static TLS block, 64-bit case.
+pub const R_E2K_64_TLS_LE: u32 = 76;
+/// ID of module containing symbol, 32-bit case.
+pub const R_E2K_TLS_32_DTPMOD: u32 = 80;
+/// Offset in module TLS block, 32-bit case.
+pub const R_E2K_TLS_32_DTPREL: u32 = 81;
+/// ID of module containing symbol, 64-bit case.
+pub const R_E2K_TLS_64_DTPMOD: u32 = 82;
+/// Offset in module TLS block, 64-bit case.
+pub const R_E2K_TLS_64_DTPREL: u32 = 83;
+/// Offset in static TLS block, 32-bit case.
+pub const R_E2K_TLS_32_TPREL: u32 = 84;
+/// Offset in static TLS block, 64-bit case.
+pub const R_E2K_TLS_64_TPREL: u32 = 85;
+
+/// Direct AP.
+pub const R_E2K_AP: u32 = 100;
+/// Direct PL.
+pub const R_E2K_PL: u32 = 101;
+
+/// 32-bit offset of the symbol's entry in GOT.
+pub const R_E2K_GOT: u32 = 108;
+/// 32-bit offset of the symbol from GOT.
+pub const R_E2K_GOTOFF: u32 = 109;
+/// PC relative 28 bit for DISP.
+pub const R_E2K_DISP: u32 = 110;
+/// Prefetch insn line containing the label (symbol).
+pub const R_E2K_PREF: u32 = 111;
+/// No reloc.
+pub const R_E2K_NONE: u32 = 112;
+/// 32-bit offset of the symbol's entry in .got.plt.
+pub const R_E2K_GOTPLT: u32 = 114;
+/// Is symbol resolved locally during the link.
+/// The result is encoded in 5-bit ALS.src1.
+pub const R_E2K_ISLOCAL: u32 = 115;
+/// Is symbol resloved locally during the link.
+/// The result is encoded in a long 32-bit LTS.
+pub const R_E2K_ISLOCAL32: u32 = 118;
+/// The symbol's offset from GOT encoded within a 64-bit literal.
+pub const R_E2K_64_GOTOFF_LIT: u32 = 256;
+/// Symbol value if resolved by the definition in the same
+/// compilation unit or NULL otherwise, 64-bit case.
+pub const R_E2K_64_DYNOPT: u32 = 257;
+/// PC relative 64 bit in data.
+pub const R_E2K_64_PC: u32 = 258;
+
+// E2K values for `Dyn32::d_tag`.
+
+pub const DT_E2K_LAZY: u32 = DT_LOPROC + 1;
+pub const DT_E2K_LAZY_GOT: u32 = DT_LOPROC + 3;
+
+pub const DT_E2K_INIT_GOT: u32 = DT_LOPROC + 0x101c;
+pub const DT_E2K_EXPORT_PL: u32 = DT_LOPROC + 0x101d;
+pub const DT_E2K_EXPORT_PLSZ: u32 = DT_LOPROC + 0x101e;
+pub const DT_E2K_REAL_PLTGOT: u32 = DT_LOPROC + 0x101f;
+pub const DT_E2K_NO_SELFINIT: u32 = DT_LOPROC + 0x1020;
+
+pub const DT_E2K_NUM: u32 = 0x1021;
+
 #[allow(non_upper_case_globals)]
 pub const Tag_File: u8 = 1;
 #[allow(non_upper_case_globals)]

src/read/elf/file.rs

@@ -209,6 +209,8 @@ where
             (elf::EM_AVR, _) => Architecture::Avr,
             (elf::EM_BPF, _) => Architecture::Bpf,
             (elf::EM_CSKY, _) => Architecture::Csky,
+            (elf::EM_MCST_ELBRUS, false) => Architecture::E2K32,
+            (elf::EM_MCST_ELBRUS, true) => Architecture::E2K64,
             (elf::EM_386, _) => Architecture::I386,
             (elf::EM_X86_64, false) => Architecture::X86_64_X32,
             (elf::EM_X86_64, true) => Architecture::X86_64,

src/read/elf/relocation.rs

@@ -294,6 +294,14 @@ fn parse_relocation<Elf: FileHeader>(
             elf::R_CKCORE_PCREL32 => (K::Relative, g, 32),
             _ => unknown,
         },
+        elf::EM_MCST_ELBRUS => match r_type {
+            elf::R_E2K_32_ABS => (K::Absolute, g, 32),
+            elf::R_E2K_64_ABS => (K::Absolute, g, 64),
+            elf::R_E2K_64_ABS_LIT => (K::Absolute, E::E2KLit, 64),
+            elf::R_E2K_DISP => (K::Relative, E::E2KDisp, 28),
+            elf::R_E2K_GOT => (K::Got, g, 32),
+            _ => unknown,
+        },
         elf::EM_386 => match r_type {
             elf::R_386_32 => (K::Absolute, g, 32),
             elf::R_386_PC32 => (K::Relative, g, 32),

src/write/elf/object.rs

@@ -126,6 +126,8 @@ impl<'a> Object<'a> {
             Architecture::Avr => true,
             Architecture::Bpf => false,
             Architecture::Csky => true,
+            Architecture::E2K32 => true,
+            Architecture::E2K64 => true,
             Architecture::I386 => false,
             Architecture::X86_64 => true,
             Architecture::X86_64_X32 => true,
@@ -218,6 +220,14 @@ impl<'a> Object<'a> {
                 (K::Relative, 8) => elf::R_386_PC8,
                 _ => return unsupported_reloc(),
             },
+            Architecture::E2K32 | Architecture::E2K64 => match (kind, encoding, size) {
+                (K::Absolute, E::Generic, 32) => elf::R_E2K_32_ABS,
+                (K::Absolute, E::E2KLit, 64) => elf::R_E2K_64_ABS_LIT,
+                (K::Absolute, E::Generic, 64) => elf::R_E2K_64_ABS,
+                (K::Relative, E::E2KDisp, 28) => elf::R_E2K_DISP,
+                (K::Got, _, 32) => elf::R_E2K_GOT,
+                _ => return unsupported_reloc(),
+            },
             Architecture::X86_64 | Architecture::X86_64_X32 => match (kind, encoding, size) {
                 (K::Absolute, E::Generic, 64) => elf::R_X86_64_64,
                 (K::Relative, E::X86Branch, 32) => elf::R_X86_64_PLT32,
@@ -521,6 +531,8 @@ impl<'a> Object<'a> {
             (Architecture::Avr, None) => elf::EM_AVR,
             (Architecture::Bpf, None) => elf::EM_BPF,
             (Architecture::Csky, None) => elf::EM_CSKY,
+            (Architecture::E2K32, None) => elf::EM_MCST_ELBRUS,
+            (Architecture::E2K64, None) => elf::EM_MCST_ELBRUS,
             (Architecture::I386, None) => elf::EM_386,
             (Architecture::X86_64, None) => elf::EM_X86_64,
             (Architecture::X86_64_X32, None) => elf::EM_X86_64,

tests/round_trip/mod.rs

@@ -265,6 +265,8 @@ fn elf_any() {
         (Architecture::Avr, Endianness::Little),
         (Architecture::Bpf, Endianness::Little),
         (Architecture::Csky, Endianness::Little),
+        (Architecture::E2K32, Endianness::Little),
+        (Architecture::E2K64, Endianness::Little),
         (Architecture::I386, Endianness::Little),
         (Architecture::X86_64, Endianness::Little),
         (Architecture::X86_64_X32, Endianness::Little),