diff --git a/ceno_emul/src/platform.rs b/ceno_emul/src/platform.rs
index d15e74db6..22c9fe6bb 100644
--- a/ceno_emul/src/platform.rs
+++ b/ceno_emul/src/platform.rs
@@ -16,11 +16,18 @@ pub struct Platform {
 }
 
 pub const CENO_PLATFORM: Platform = Platform {
-    rom_start: 0x2000_0000,
-    rom_end: 0x3000_0000 - 1,
-    ram_start: 0x0020_0000,
-    ram_end: 0x0040_0000 - 1,
-    unsafe_ecall_nop: false,
+    // rom_start: 0x2000_0000,
+    // rom_end: 0x3000_0000 - 1,
+    // ram_start: 0x0020_0000,
+    // ram_end: 0x0040_0000 - 1,
+    // unsafe_ecall_nop: false,
+
+    // SP1
+    rom_start: 0x0020_0800,
+    rom_end: 0x0020a110 - 1,
+    ram_start: 0x0001_0000,
+    ram_end: 0x8001_0000 - 1,
+    unsafe_ecall_nop: true,
 };
 
 impl Platform {
@@ -118,7 +125,7 @@ impl Platform {
     }
 
     pub fn can_execute(&self, addr: Addr) -> bool {
-        self.is_rom(addr)
+        true // self.is_rom(addr)
     }
 
     // Environment calls.
@@ -147,6 +154,15 @@ impl Platform {
     pub const fn code_success(&self) -> u32 {
         0
     }
+
+    pub fn format_segment(&self, addr: u32) -> String {
+        format!(
+            "{}{}{}",
+            if self.can_read(addr) { "R" } else { "-" },
+            if self.can_write(addr) { "W" } else { "-" },
+            if self.can_execute(addr) { "X" } else { "-" },
+        )
+    }
 }
 
 #[cfg(test)]
diff --git a/ceno_zkvm/examples/fibonacci_elf.rs b/ceno_zkvm/examples/fibonacci_elf.rs
index db61722fe..80336ad16 100644
--- a/ceno_zkvm/examples/fibonacci_elf.rs
+++ b/ceno_zkvm/examples/fibonacci_elf.rs
@@ -56,13 +56,7 @@ fn main() {
         .with(flame_layer.with_threads_collapsed(true));
     tracing::subscriber::set_global_default(subscriber).unwrap();
 
-    let sp1_platform = Platform {
-        rom_start: 0x0020_0800,
-        rom_end: 0x003f_ffff,
-        ram_start: 0x0020_0000,
-        ram_end: 0xffff_ffff,
-        unsafe_ecall_nop: true,
-    };
+    let sp1_platform = CENO_PLATFORM.clone();
     const STACK_TOP: u32 = 0x0020_0400;
     const STACK_SIZE: u32 = 1;