Add the SectionType::Vector enum value

It's actually valuable to distinguish that part of PRG-ROM that is part
of the vectors segment.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

2 files changed, 14 insertions, 3 deletions

diff --git a/lib/xixanta/src/cfg.rs b/lib/xixanta/src/cfg.rs
index 52e075e..eacc5a4 100644
--- a/lib/xixanta/src/cfg.rs
+++ b/lib/xixanta/src/cfg.rs
@@ -269,6 +269,8 @@ pub fn parse_cfg_file(text: &str) -> Result<Vec<Mapping>, String> {
         //      realized it's CHR ROM.
         if header {
             header = false;
+        } else if start == 0xFFFA && size == 6 {
+            section_type = SectionType::Vector;
         } else if start == 0x0000 {
             section_type = SectionType::ChrRom;
         } else if section_type != SectionType::ChrRom {
@@ -355,6 +357,8 @@ pub fn parse_nasm_cfg_file(text: &str) -> Result<Vec<Mapping>, String> {
         //      realized it's CHR ROM.
         if header {
             header = false;
+        } else if start == 0xFFFA && size == 6 {
+            section_type = SectionType::Vector;
         } else if start == 0x0000 {
             section_type = SectionType::ChrRom;
         } else if section_type != SectionType::ChrRom {
@@ -485,7 +489,7 @@ FEATURES {
         assert_eq!(romv.start, 0xFFFA);
         assert_eq!(romv.size, 0x06);
         assert_eq!(romv.fill, Some(0x00));
-        assert_eq!(romv.section_type, SectionType::PrgRom);
+        assert_eq!(romv.section_type, SectionType::Vector);
         assert_eq!(
             romv.segments
                 .iter()
diff --git a/lib/xixanta/src/mapping.rs b/lib/xixanta/src/mapping.rs
index 2270ad3..fe255d2 100644
--- a/lib/xixanta/src/mapping.rs
+++ b/lib/xixanta/src/mapping.rs
@@ -18,6 +18,9 @@ pub enum SectionType {
 
     /// Bank to be stored in CHR ROM with a size multiple of 4KB.
     ChrRom,
+
+    /// The 6 final bytes describing the addresses for nmi, reset and irq.
+    Vector,
 }
 
 /// A segment inside of a memory mapping, used to organize the code inside of a
@@ -149,11 +152,15 @@ fn validate_configuration(mappings: &[Mapping]) -> Result<(), String> {
         .iter()
         .filter(|m| m.section_type == SectionType::PrgRom)
         .fold(0, |acc, x| acc + x.size);
+    let vec_rom_len = mappings
+        .iter()
+        .filter(|m| m.section_type == SectionType::Vector)
+        .fold(0, |acc, x| acc + x.size);
 
-    if prg_rom_len < 0x4000 {
+    if prg_rom_len + vec_rom_len < 0x4000 {
         return Err("PRG ROM must be at least 8KB long".to_string());
     }
-    if prg_rom_len % 0x4000 != 0 {
+    if (prg_rom_len + vec_rom_len) % 0x4000 != 0 {
         return Err("PRG ROM must be formed by banks of exactly 8KB".to_string());
     }