ec: Assume ROM size is total flash size

Remove the hard-coded assumption that the EC is always 128K, as ITE
chips can also be 256K (which Clevo has started using since addw4).
Instead assume the ROM is correctly sized, which we do since
system76/ec@0d83819a21f87 ("Pad binary file to total flash size") and
proprietary firmware has always done.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

src/app/ec.rs

@@ -228,9 +228,10 @@ impl EcComponent {
         // Special case for pang12, pang13, and pang14
         match &self.ec {
             EcKind::Pang(_pmc, _system_version) => {
-                return data.len() == 128 * 1024
-                    && &data[0x50 ..= 0x05F] == b"ITE EC-V14.6   \0";
-            },
+                // XXX: Get flash size programatically?
+                return (data.len() == 128 * 1024 || data.len() == 256 * 1024)
+                    && &data[0x50..=0x05F] == b"ITE EC-V14.6   \0";
+            }
             _ => (),
         }
 
@@ -314,12 +315,10 @@ impl<T: Timeout> SpiLegacy<T> {
         }
     }
 
-    fn rom_size(&self) -> usize {
-        128 * 1024
-    }
     fn block_size(&self) -> usize {
         64 * 1024
     }
+
     fn page_size(&self) -> usize {
         256
     }
@@ -401,10 +400,13 @@ impl<T: Timeout> SpiLegacy<T> {
 unsafe fn flash_legacy(firmware_data: &[u8]) -> core::result::Result<(), ectool::Error> {
     let mut spi = SpiLegacy::new(UefiTimeout::new(1_000_000));
 
-    let rom_size = spi.rom_size();
-    let mut new_rom = firmware_data.to_vec();
-    while new_rom.len() < rom_size {
-        new_rom.push(0xFF);
+    let new_rom = firmware_data.to_vec();
+
+    // XXX: Get flash size programatically?
+    let rom_size = new_rom.len();
+    if rom_size % 1024 != 0 {
+        println!("ROM size of {} is not valid", rom_size);
+        return Err(ectool::Error::Verify);
     }
 
     println!("Entering scratch ROM");
@@ -534,11 +536,13 @@ unsafe fn flash(
         println!("ec version: {:?}", str::from_utf8(ec_version));
     }
 
-    let rom_size = 128 * 1024;
+    let new_rom = firmware_data.to_vec();
 
-    let mut new_rom = firmware_data.to_vec();
-    while new_rom.len() < rom_size {
-        new_rom.push(0xFF);
+    // XXX: Get flash size programatically?
+    let rom_size = new_rom.len();
+    if rom_size % 1024 != 0 {
+        println!("ROM size of {} is not valid", rom_size);
+        return Err(ectool::Error::Verify);
     }
 
     let mut spi_bus = ec.spi(SpiTarget::Main, true)?;