Implement linker_offset

Fixes #35

docs/file_format/file.md

@@ -33,14 +33,14 @@ Specifies the type of file entry.
 ### Example
 
 The following example forces the position of the linker script to advance 0x10
-bytes after the the `boot_main.o` file, but only for the `.text` pad_section.
+bytes after the the `boot_main.o` file, but only for the `.text` section.
 
 ```yaml
 segments:
   - name: boot
     files:
       - { path: src/boot/boot_main.o }
-      - { kind: pad, pad_amount: 0x10, pad_section: .text }
+      - { kind: pad, pad_amount: 0x10, section: .text }
       - { path: src/boot/dmadata.o }
 ```
 
@@ -49,9 +49,11 @@ segments:
 - `object`: The path points to a relocatable object file. The [`path`](#path) is
   required.
 - `pad`: Do not link any file but increment the position of the
-  [`pad_section`](#pad_section) in the linker script by
-  [`pad_amount`](#pad_amount) bytes. Both [`pad_section`](#pad_section) and
-  [`pad_amount`](#pad_amount) are required.
+  [`section`](#section) in the linker script by [`pad_amount`](#pad_amount)
+  bytes. Both [`section`](#section) and [`pad_amount`](#pad_amount) are required.
+- `linker_offset`: Emit a symbol between the files at a given
+  [`section`](#section). Both [`section`](#section) and
+  [`linker_offset_name`](#linker_offset_name) are required.
 
 ### Default value
 
@@ -71,20 +73,31 @@ The amount of bytes to increment the position in the linker script used on `pad`
 segments:
   - name: boot
     files:
-      - { kind: pad, pad_amount: 0x10, pad_section: .text }
+      - { kind: pad, pad_amount: 0x10, section: .text }
 ```
 
 ### Valid values
 
 Positive integers.
 
-## `pad_section`
+## `section`
 
 This field have different meanings depending on the file [`kind`](#kind):
 
 - `object`: This field is invalid.
-- `pad`: The position of the linker script will advance only for this
-  pad_section.
+- `pad`: The position of the linker script will advance only for this section.
+- `linker_offset`: The section where the linker offset symbol will be emitted.
+
+### Valid values
+
+Non empty string.
+
+## `linker_offset_name`
+
+The name to be used for the generated `linker offset` [`kind`](#kind).
+
+This name is not used as-is, instead it is controlled by the global
+[`linker_symbols_style`](settings.md#linker_symbols_style) setting
 
 ### Valid values
 

docs/file_format/settings.md

@@ -61,6 +61,7 @@ settings:
     - `.text`: `boot_TEXT_START`, `boot_TEXT_END` and `boot_TEXT_SIZE`.
     - `.data`: `boot_DATA_START`, `boot_DATA_END` and `boot_DATA_SIZE`.
     - `.bss`: `boot_BSS_START`, `boot_BSS_END` and `boot_BSS_SIZE`.
+  - File [`linker_offset_name`](file.md#linker_offset_name): `{name}_OFFSET`
 
 - `makerom`: Produces _camelCase symbols. Given a segment named `boot`:
   - Segment rom: `_bootSegmentRomStart`, `_bootSegmentRomEnd` and `_bootSegmentRomSize`.
@@ -69,6 +70,7 @@ settings:
     - `.text`: `_bootSegmentTextStart`, `_bootSegmentTextEnd` and `_bootSegmentTextSize`.
     - `.data`: `_bootSegmentDataStart`, `_bootSegmentDataEnd` and `_bootSegmentDataSize`.
     - `.bss`: `_bootSegmentBssStart`, `_bootSegmentBssEnd` and `_bootSegmentBssSize`.
+  - File [`linker_offset_name`](file.md#linker_offset_name): `_{name}Offset`
 
 ### Default value
 

slinky/src/file_info.rs

@@ -13,7 +13,9 @@ pub struct FileInfo {
     pub kind: FileKind,
 
     pub pad_amount: u32,
-    pub pad_section: String,
+    pub section: String,
+
+    pub linker_offset_name: String,
 }
 
 #[derive(Deserialize, PartialEq, Debug)]
@@ -28,7 +30,10 @@ pub(crate) struct FileInfoSerial {
     #[serde(default)]
     pub pad_amount: AbsentNullable<u32>,
     #[serde(default)]
-    pub pad_section: AbsentNullable<String>,
+    pub section: AbsentNullable<String>,
+
+    #[serde(default)]
+    pub linker_offset_name: AbsentNullable<String>,
 }
 
 impl FileInfoSerial {
@@ -47,11 +52,11 @@ impl FileInfoSerial {
 
                     (p, k)
                 }
-                FileKind::Pad => {
+                FileKind::Pad | FileKind::LinkerOffset => {
                     // pad doesn't allow for paths
                     if self.path.has_value() {
                         return Err(SlinkyError::InvalidFieldCombo {
-                            field1: "kind: pad".into(),
+                            field1: "kind: pad or kind: linker_offset".into(),
                             field2: "path".into(),
                         });
                     }
@@ -74,7 +79,7 @@ impl FileInfoSerial {
         };
 
         let pad_amount = match kind {
-            FileKind::Object => {
+            FileKind::Object | FileKind::LinkerOffset => {
                 if self.pad_amount.has_value() {
                     return Err(SlinkyError::InvalidFieldCombo {
                         field1: "pad_amount".into(),
@@ -86,24 +91,38 @@ impl FileInfoSerial {
             FileKind::Pad => self.pad_amount.get("pad_amount")?,
         };
 
-        let pad_section = match kind {
+        let section = match kind {
             FileKind::Object => {
-                if self.pad_section.has_value() {
+                if self.section.has_value() {
                     return Err(SlinkyError::InvalidFieldCombo {
-                        field1: "pad_section".into(),
+                        field1: "section".into(),
                         field2: "non `kind: pad`".into(),
                     });
                 }
                 "".into()
             }
-            FileKind::Pad => self.pad_section.get("pad_section")?,
+            FileKind::Pad | FileKind::LinkerOffset => self.section.get("section")?,
+        };
+
+        let linker_offset_name = match kind {
+            FileKind::Object | FileKind::Pad => {
+                if self.linker_offset_name.has_value() {
+                    return Err(SlinkyError::InvalidFieldCombo {
+                        field1: "linker_offset_name".into(),
+                        field2: "non `kind: linker_offset`".into(),
+                    });
+                }
+                "".into()
+            }
+            FileKind::LinkerOffset => self.linker_offset_name.get("linker_offset_name")?,
         };
 
         Ok(FileInfo {
             path,
             kind,
             pad_amount,
-            pad_section,
+            section,
+            linker_offset_name,
         })
     }
 }

slinky/src/file_kind.rs

@@ -11,6 +11,7 @@ pub enum FileKind {
     Object,
     // Archive,
     Pad,
+    LinkerOffset,
 }
 
 impl FileKind {

slinky/src/linker_symbols_style.rs

@@ -97,4 +97,11 @@ impl LinkerSymbolsStyle {
             LinkerSymbolsStyle::Makerom => format!("_{}Segment{}Size", seg_name, sec),
         }
     }
+
+    pub fn linker_offset(&self, name: &str) -> String {
+        match self {
+            LinkerSymbolsStyle::Splat => format!("{}_OFFSET", name),
+            LinkerSymbolsStyle::Makerom => format!("_{}Offset", name),
+        }
+    }
 }

slinky/src/linker_writer.rs

@@ -283,6 +283,8 @@ impl LinkerWriter<'_> {
     }
 
     fn write_files_for_section(&mut self, segment: &Segment, section: &str) {
+        let style = &self.settings.linker_symbols_style;
+
         for file in &segment.files {
             let mut path = self.settings.base_path.clone();
 
@@ -297,10 +299,15 @@ impl LinkerWriter<'_> {
                 }
                 //FileKind::Archive => todo!(),
                 FileKind::Pad => {
-                    if file.pad_section == section {
+                    if file.section == section {
                         self.writeln(&format!(". += 0x{:X};", file.pad_amount));
                     }
                 }
+                FileKind::LinkerOffset => {
+                    if file.section == section {
+                        self.write_symbol(&style.linker_offset(&file.linker_offset_name), ".");
+                    }
+                }
             }
         }
     }

tests/input_files/linker_offset.yaml

@@ -0,0 +1,12 @@
+settings:
+  base_path: build
+
+segments:
+  - name: main
+    files:
+      - { kind: linker_offset, linker_offset_name: main_data_start, section: .data }
+      - { path: src/main/boot_main.o }
+      - { path: src/main/dmadata.o }
+      - { path: asm/main/util.o }
+      - { kind: linker_offset, linker_offset_name: libultra_start, section: .text }
+      - { path: src/libultra/libc/bzero.o }

tests/input_files/pad_test.yaml

@@ -5,9 +5,9 @@ segments:
   - name: boot
     files:
       - { path: src/boot/boot_main.o }
-      - { kind: pad, pad_amount: 0x40, pad_section: .text }
+      - { kind: pad, pad_amount: 0x40, section: .text }
       - { path: src/boot/dmadata.o }
-      - { kind: pad, pad_amount: 0x20, pad_section: .rodata }
+      - { kind: pad, pad_amount: 0x20, section: .rodata }
       - { path: asm/util.o }
-      - { kind: pad, pad_amount: 0x60, pad_section: .bss }
+      - { kind: pad, pad_amount: 0x60, section: .bss }
       - { path: src/boot/unused_file.o }

tests/linker_scripts/linker_offset.ld

@@ -0,0 +1,107 @@
+SECTIONS
+{
+    __romPos = 0x0;
+
+    main_ROM_START = __romPos;
+    main_VRAM = ADDR(.main);
+    main_alloc_VRAM = .;
+    .main : AT(main_ROM_START) SUBALIGN(16)
+    {
+        FILL(0x00000000);
+        main_TEXT_START = .;
+        build/src/main/boot_main.o(.text*);
+        build/src/main/dmadata.o(.text*);
+        build/asm/main/util.o(.text*);
+        libultra_start_OFFSET = .;
+        build/src/libultra/libc/bzero.o(.text*);
+        main_TEXT_END = .;
+        main_TEXT_SIZE = ABSOLUTE(main_TEXT_END - main_TEXT_START);
+
+        main_DATA_START = .;
+        main_data_start_OFFSET = .;
+        build/src/main/boot_main.o(.data*);
+        build/src/main/dmadata.o(.data*);
+        build/asm/main/util.o(.data*);
+        build/src/libultra/libc/bzero.o(.data*);
+        main_DATA_END = .;
+        main_DATA_SIZE = ABSOLUTE(main_DATA_END - main_DATA_START);
+
+        main_RODATA_START = .;
+        build/src/main/boot_main.o(.rodata*);
+        build/src/main/dmadata.o(.rodata*);
+        build/asm/main/util.o(.rodata*);
+        build/src/libultra/libc/bzero.o(.rodata*);
+        main_RODATA_END = .;
+        main_RODATA_SIZE = ABSOLUTE(main_RODATA_END - main_RODATA_START);
+
+        main_SDATA_START = .;
+        build/src/main/boot_main.o(.sdata*);
+        build/src/main/dmadata.o(.sdata*);
+        build/asm/main/util.o(.sdata*);
+        build/src/libultra/libc/bzero.o(.sdata*);
+        main_SDATA_END = .;
+        main_SDATA_SIZE = ABSOLUTE(main_SDATA_END - main_SDATA_START);
+    }
+    main_alloc_VRAM_END = .;
+    main_alloc_VRAM_SIZE = ABSOLUTE(main_alloc_VRAM_END - main_alloc_VRAM);
+
+    main_noload_VRAM = .;
+    .main.noload (NOLOAD) : SUBALIGN(16)
+    {
+        FILL(0x00000000);
+        main_SBSS_START = .;
+        build/src/main/boot_main.o(.sbss*);
+        build/src/main/dmadata.o(.sbss*);
+        build/asm/main/util.o(.sbss*);
+        build/src/libultra/libc/bzero.o(.sbss*);
+        main_SBSS_END = .;
+        main_SBSS_SIZE = ABSOLUTE(main_SBSS_END - main_SBSS_START);
+
+        main_SCOMMON_START = .;
+        build/src/main/boot_main.o(.scommon*);
+        build/src/main/dmadata.o(.scommon*);
+        build/asm/main/util.o(.scommon*);
+        build/src/libultra/libc/bzero.o(.scommon*);
+        main_SCOMMON_END = .;
+        main_SCOMMON_SIZE = ABSOLUTE(main_SCOMMON_END - main_SCOMMON_START);
+
+        main_BSS_START = .;
+        build/src/main/boot_main.o(.bss*);
+        build/src/main/dmadata.o(.bss*);
+        build/asm/main/util.o(.bss*);
+        build/src/libultra/libc/bzero.o(.bss*);
+        main_BSS_END = .;
+        main_BSS_SIZE = ABSOLUTE(main_BSS_END - main_BSS_START);
+
+        mainCOMMON_START = .;
+        build/src/main/boot_main.o(COMMON*);
+        build/src/main/dmadata.o(COMMON*);
+        build/asm/main/util.o(COMMON*);
+        build/src/libultra/libc/bzero.o(COMMON*);
+        mainCOMMON_END = .;
+        mainCOMMON_SIZE = ABSOLUTE(mainCOMMON_END - mainCOMMON_START);
+    }
+    main_noload_VRAM_END = .;
+    main_noload_VRAM_SIZE = ABSOLUTE(main_noload_VRAM_END - main_noload_VRAM);
+    main_VRAM_END = .;
+    main_VRAM_SIZE = ABSOLUTE(main_VRAM_END - main_VRAM);
+    __romPos += SIZEOF(.main);
+    main_ROM_END = __romPos;
+    main_ROM_SIZE = ABSOLUTE(main_ROM_END - main_ROM_START);
+
+    .shstrtab 0 :
+    {
+        *(.shstrtab);
+    }
+
+    /DISCARD/ :
+    {
+        *(.reginfo);
+        *(.MIPS.abiflags);
+        *(.MIPS.options);
+        *(.note.gnu.build-id);
+        *(.interp);
+        *(.eh_frame);
+        *(*);
+    }
+}

tests/panics/kind_offset_no_name.yaml

@@ -0,0 +1,7 @@
+settings:
+  base_path: build
+
+segments:
+  - name: main
+    files:
+      - { kind: linker_offset, section: .data }

tests/panics/kind_pad_no_amount.yaml

@@ -1,4 +1,4 @@
 segments:
   - name: main
     files:
-      - { kind: pad, pad_section: .text }
+      - { kind: pad, section: .text }

tests/panics/section_non_kind_pad.yaml

@@ -1,4 +1,4 @@
 segments:
   - name: main
     files:
-      - { path: src/boot/boot_main.o, pad_section: .text }
+      - { path: src/boot/boot_main.o, section: .text }