coff: add base relocation related types

lib/std/coff.zig

@@ -310,6 +310,84 @@ pub const ImageDataDirectory = extern struct {
     size: u32,
 };
 
+pub const BaseRelocationDirectoryEntry = extern struct {
+    /// The image base plus the page RVA is added to each offset to create the VA where the base relocation must be applied.
+    page_rva: u32,
+
+    /// The total number of bytes in the base relocation block, including the Page RVA and Block Size fields and the Type/Offset fields that follow.
+    block_size: u32,
+};
+
+pub const BaseRelocation = packed struct {
+    /// Stored in the remaining 12 bits of the WORD, an offset from the starting address that was specified in the Page RVA field for the block.
+    /// This offset specifies where the base relocation is to be applied.
+    offset: u12,
+
+    /// Stored in the high 4 bits of the WORD, a value that indicates the type of base relocation to be applied.
+    @"type": BaseRelocationType,
+};
+
+pub const BaseRelocationType = enum(u4) {
+    /// The base relocation is skipped. This type can be used to pad a block.
+    ABSOLUTE = 0,
+
+    /// The base relocation adds the high 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the high value of a 32-bit word.
+    HIGH = 1,
+
+    /// The base relocation adds the low 16 bits of the difference to the 16-bit field at offset. The 16-bit field represents the low half of a 32-bit word.
+    LOW = 2,
+
+    /// The base relocation applies all 32 bits of the difference to the 32-bit field at offset.
+    HIGHLOW = 3,
+
+    /// The base relocation adds the high 16 bits of the difference to the 16-bit field at offset.
+    /// The 16-bit field represents the high value of a 32-bit word.
+    /// The low 16 bits of the 32-bit value are stored in the 16-bit word that follows this base relocation.
+    /// This means that this base relocation occupies two slots.
+    HIGHADJ = 4,
+
+    /// When the machine type is MIPS, the base relocation applies to a MIPS jump instruction.
+    MIPS_JMPADDR = 5,
+
+    /// This relocation is meaningful only when the machine type is ARM or Thumb.
+    /// The base relocation applies the 32-bit address of a symbol across a consecutive MOVW/MOVT instruction pair.
+    // ARM_MOV32 = 5,
+
+    /// This relocation is only meaningful when the machine type is RISC-V.
+    /// The base relocation applies to the high 20 bits of a 32-bit absolute address.
+    // RISCV_HIGH20 = 5,
+
+    /// Reserved, must be zero.
+    RESERVED = 6,
+
+    /// This relocation is meaningful only when the machine type is Thumb.
+    /// The base relocation applies the 32-bit address of a symbol to a consecutive MOVW/MOVT instruction pair.
+    THUMB_MOV32 = 7,
+
+    /// This relocation is only meaningful when the machine type is RISC-V.
+    /// The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V I-type instruction format.
+    // RISCV_LOW12I = 7,
+
+    /// This relocation is only meaningful when the machine type is RISC-V.
+    /// The base relocation applies to the low 12 bits of a 32-bit absolute address formed in RISC-V S-type instruction format.
+    RISCV_LOW12S = 8,
+
+    /// This relocation is only meaningful when the machine type is LoongArch 32-bit.
+    /// The base relocation applies to a 32-bit absolute address formed in two consecutive instructions.
+    // LOONGARCH32_MARK_LA = 8,
+
+    /// This relocation is only meaningful when the machine type is LoongArch 64-bit.
+    /// The base relocation applies to a 64-bit absolute address formed in four consecutive instructions.
+    // LOONGARCH64_MARK_LA = 8,
+
+    /// The relocation is only meaningful when the machine type is MIPS.
+    /// The base relocation applies to a MIPS16 jump instruction.
+    MIPS_JMPADDR16 = 9,
+
+    /// The base relocation applies the difference to the 64-bit field at offset.
+    DIR64 = 10,
+};
+
 pub const DebugDirectoryEntry = extern struct {
     characteristics: u32,
     time_date_stamp: u32,