Implement segment_start_align

Fixes #21

docs/file_format/segments.md

@@ -154,6 +154,33 @@ Positive integers or `null`.
 
 The value specified for [settings.md#subalign](settings.md#subalign)
 
+## `segment_start_align`
+
+Force aligning the beginning of this specific segment to the specified value.
+
+If the value is `null` then no alignment will be forced at the start of this
+specific segment.
+
+This option overrides the global setting, see
+[settings.md#segment_start_align](settings.md#segment_start_align) for more info.
+
+### Example
+
+```yaml
+segments:
+  - name: gameplay_keep
+    segment_start_align: 0x1000
+```
+
+### Valid values
+
+Positive integers or `null`.
+
+### Default value
+
+The value specified for
+[settings.md#segment_start_align](settings.md#segment_start_align)
+
 ## `section_end_align`
 
 Force aligning the end of each section for this segment to the specified value.
@@ -178,7 +205,8 @@ Positive integers or `null`.
 
 ### Default value
 
-The value specified for [settings.md#section_end_align](settings.md#section_end_align)
+The value specified for
+[settings.md#section_end_align](settings.md#section_end_align)
 
 ## `wildcard_sections`
 

docs/file_format/settings.md

@@ -277,6 +277,30 @@ Positive integers or `null`.
 
 `0x10`
 
+## `segment_start_align`
+
+Force aligning the beginning of the segment to the specified value.
+
+If the value is `null` then no alignment will be forced.
+
+This option can be overriden per segment, see
+[segments.md#segment_start_align](segments.md#segment_start_align) for more info.
+
+### Example
+
+```yaml
+settings:
+  segment_start_align: 0x10
+```
+
+### Valid values
+
+Positive integers or `null`.
+
+### Default value
+
+`null`
+
 ## `section_end_align`
 
 Force aligning the end of each section to the specified value.

slinky/src/linker_writer.rs

@@ -119,6 +119,11 @@ impl<'a> LinkerWriter<'a> {
         let main_seg_sym_end: String = style.segment_vram_end(&segment.name);
         let main_seg_sym_size: String = style.segment_vram_size(&segment.name);
 
+        if let Some(segment_start_align) = segment.segment_start_align {
+            self.align_symbol("__romPos", segment_start_align);
+            self.align_symbol(".", segment_start_align);
+        }
+
         self.write_symbol(&main_seg_rom_sym_start, "__romPos");
         self.write_symbol(&main_seg_sym_start, &format!("ADDR({})", dotted_seg_name));
 
@@ -138,7 +143,6 @@ impl<'a> LinkerWriter<'a> {
         );
 
         self.writeln(&format!("__romPos += SIZEOF({});", dotted_seg_name));
-        // self.writeln(&format!("__romPos = ALIGN(__romPos, {});", ));
         self.write_sym_end_size(
             &main_seg_rom_sym_start,
             &main_seg_rom_sym_end,
@@ -230,6 +234,13 @@ impl LinkerWriter<'_> {
         self.linker_symbols.insert(value.to_string());
     }
 
+    fn align_symbol(&mut self, symbol: &str, align_value: u32) {
+        self.writeln(&format!(
+            "{} = ALIGN({}, 0x{:X});",
+            symbol, symbol, align_value
+        ));
+    }
+
     fn write_sym_end_size(&mut self, start: &str, end: &str, size: &str, value: &str) {
         self.write_symbol(end, value);
 
@@ -355,7 +366,7 @@ impl LinkerWriter<'_> {
             self.emit_section(segment, section);
 
             if let Some(section_end_align) = segment.section_end_align {
-                self.writeln(&format!(". = ALIGN(0x{:X})", section_end_align));
+                self.align_symbol(".", section_end_align);
             }
             self.write_sym_end_size(&section_start_sym, &section_end_sym, &section_size_sym, ".");
 

slinky/src/segment.rs

@@ -30,6 +30,7 @@ pub struct Segment {
     pub noload_sections: Vec<String>,
 
     pub subalign: Option<u32>,
+    pub segment_start_align: Option<u32>,
     pub section_end_align: Option<u32>,
 
     pub wildcard_sections: bool,
@@ -56,6 +57,8 @@ pub(crate) struct SegmentSerial {
     #[serde(default)]
     pub subalign: AbsentNullable<u32>,
     #[serde(default)]
+    pub segment_start_align: AbsentNullable<u32>,
+    #[serde(default)]
     pub section_end_align: AbsentNullable<u32>,
 
     #[serde(default)]
@@ -111,6 +114,10 @@ impl SegmentSerial {
             .subalign
             .get_optional_nullable("subalign", || settings.subalign)?;
 
+        let segment_start_align = self
+            .segment_start_align
+            .get_optional_nullable("segment_start_align", || settings.segment_start_align)?;
+
         let section_end_align = self
             .section_end_align
             .get_optional_nullable("section_end_align", || settings.section_end_align)?;
@@ -131,6 +138,7 @@ impl SegmentSerial {
             alloc_sections,
             noload_sections,
             subalign,
+            segment_start_align,
             section_end_align,
             wildcard_sections,
             fill_value,

slinky/src/settings.rs

@@ -25,6 +25,7 @@ pub struct Settings {
     pub noload_sections: Vec<String>,
 
     pub subalign: Option<u32>,
+    pub segment_start_align: Option<u32>,
     pub section_end_align: Option<u32>,
 
     pub wildcard_sections: bool,
@@ -91,6 +92,10 @@ fn settings_default_subalign() -> Option<u32> {
     Some(0x10)
 }
 
+fn settings_default_segment_start_align() -> Option<u32> {
+    None
+}
+
 fn settings_default_section_end_align() -> Option<u32> {
     Some(0x10)
 }
@@ -120,6 +125,7 @@ impl Default for Settings {
             noload_sections: settings_default_noload_sections(),
 
             subalign: settings_default_subalign(),
+            segment_start_align: settings_default_segment_start_align(),
             section_end_align: settings_default_section_end_align(),
 
             wildcard_sections: settings_default_wildcard_sections(),
@@ -158,6 +164,8 @@ pub(crate) struct SettingsSerial {
     #[serde(default)]
     pub subalign: AbsentNullable<u32>,
     #[serde(default)]
+    pub segment_start_align: AbsentNullable<u32>,
+    #[serde(default)]
     pub section_end_align: AbsentNullable<u32>,
 
     #[serde(default)]
@@ -207,6 +215,10 @@ impl SettingsSerial {
             .subalign
             .get_optional_nullable("subalign", settings_default_subalign)?;
 
+        let segment_start_align = self
+            .segment_start_align
+            .get_optional_nullable("segment_start_align", settings_default_segment_start_align)?;
+
         let section_end_align = self
             .section_end_align
             .get_optional_nullable("section_end_align", settings_default_section_end_align)?;
@@ -230,6 +242,7 @@ impl SettingsSerial {
             alloc_sections,
             noload_sections,
             subalign,
+            segment_start_align,
             section_end_align,
             wildcard_sections,
             fill_value,

tests/input_files/makerom_zelda_like.yaml

@@ -5,8 +5,8 @@ settings:
 
 segments:
   - name: makerom
-    alloc_sections: [".data", ".text", ".rodata"]
     fixed_vram: 0x80024C00
+    alloc_sections: [".data", ".text", ".rodata"]
     files:
       - { path: makerom/header.o }
       - { path: makerom/ipl3.o }
@@ -15,3 +15,21 @@ segments:
   - name: boot
     files:
       - { path: boot/boot_main.o }
+
+  - name: gameplay_keep
+    fixed_vram: 0x04000000
+    segment_start_align: 0x1000
+    files:
+      - { path: assets/objects/gameplay_keep/gameplay_keep.o }
+
+  - name: gameplay_dangeon_keep
+    fixed_vram: 0x05000000
+    segment_start_align: 0x1000
+    files:
+      - { path: assets/objects/gameplay_dangeon_keep/gameplay_dangeon_keep.o }
+
+  - name: gameplay_dangeon_keep
+    fixed_vram: 0x05000000
+    segment_start_align: 0x1000
+    files:
+      - { path: assets/objects/gameplay_dangeon_keep/gameplay_dangeon_keep.o }

tests/linker_scripts/archives.ld

@@ -20,7 +20,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.text*);
         build/lib/libmus.a:lib_memory.o(.text*);
         build/lib/libmus.a:aud_samples.o(.text*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_TEXT_END = .;
         boot_TEXT_SIZE = ABSOLUTE(boot_TEXT_END - boot_TEXT_START);
 
@@ -36,7 +36,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.data*);
         build/lib/libmus.a:lib_memory.o(.data*);
         build/lib/libmus.a:aud_samples.o(.data*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_DATA_END = .;
         boot_DATA_SIZE = ABSOLUTE(boot_DATA_END - boot_DATA_START);
 
@@ -52,7 +52,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.rodata*);
         build/lib/libmus.a:lib_memory.o(.rodata*);
         build/lib/libmus.a:aud_samples.o(.rodata*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_RODATA_END = .;
         boot_RODATA_SIZE = ABSOLUTE(boot_RODATA_END - boot_RODATA_START);
 
@@ -68,7 +68,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.sdata*);
         build/lib/libmus.a:lib_memory.o(.sdata*);
         build/lib/libmus.a:aud_samples.o(.sdata*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_SDATA_END = .;
         boot_SDATA_SIZE = ABSOLUTE(boot_SDATA_END - boot_SDATA_START);
     }
@@ -91,7 +91,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.sbss*);
         build/lib/libmus.a:lib_memory.o(.sbss*);
         build/lib/libmus.a:aud_samples.o(.sbss*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_SBSS_END = .;
         boot_SBSS_SIZE = ABSOLUTE(boot_SBSS_END - boot_SBSS_START);
 
@@ -107,7 +107,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.scommon*);
         build/lib/libmus.a:lib_memory.o(.scommon*);
         build/lib/libmus.a:aud_samples.o(.scommon*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_SCOMMON_END = .;
         boot_SCOMMON_SIZE = ABSOLUTE(boot_SCOMMON_END - boot_SCOMMON_START);
 
@@ -123,7 +123,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(.bss*);
         build/lib/libmus.a:lib_memory.o(.bss*);
         build/lib/libmus.a:aud_samples.o(.bss*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         boot_BSS_END = .;
         boot_BSS_SIZE = ABSOLUTE(boot_BSS_END - boot_BSS_START);
 
@@ -139,7 +139,7 @@ SECTIONS
         build/lib/libmus.a:aud_thread.o(COMMON*);
         build/lib/libmus.a:lib_memory.o(COMMON*);
         build/lib/libmus.a:aud_samples.o(COMMON*);
-        . = ALIGN(0x10)
+        . = ALIGN(., 0x10);
         bootCOMMON_END = .;
         bootCOMMON_SIZE = ABSOLUTE(bootCOMMON_END - bootCOMMON_START);
     }