Enable overwrite-only testing on sim

Adds the feature to enable testing of overwrite-only functionality.
While running with this feature enabled, disable tests that try to
revert and disables trailer verification, since overwrite-only doesn't
rely on status writing.

Signed-off-by: Fabio Utzig <utzig@apache.org>

.travis.yml

@@ -2,9 +2,12 @@
 
 language: rust
 script:
-  - cd sim; cargo build --release
-  - cd sim; cargo run --release -- runall
-  - cd sim; cargo run --release --features sig-rsa -- runall
+  - set -e
+  - cd sim
+  - cargo build --release
+  - cargo run --release -- runall
+  - cargo run --release --features sig-rsa -- runall
+  - cargo run --release --features overwrite-only -- runall
 
 notifications:
   slack:

sim/Cargo.toml

@@ -7,6 +7,7 @@ authors = ["David Brown <davidb@davidb.org>"]
 default = []
 
 sig-rsa = ["mcuboot-sys/sig-rsa"]
+overwrite-only = ["mcuboot-sys/overwrite-only"]
 
 [build-dependencies]
 gcc = "0.3.38"

sim/src/main.rs

@@ -315,6 +315,13 @@ fn run_basic_upgrade(flash: &SimFlash, areadesc: &AreaDesc, images: &Images)
     }
 }
 
+#[cfg(feature = "overwrite-only")]
+#[allow(unused_variables)]
+fn run_basic_revert(flash: &SimFlash, areadesc: &AreaDesc, images: &Images) -> bool {
+    false
+}
+
+#[cfg(not(feature = "overwrite-only"))]
 fn run_basic_revert(flash: &SimFlash, areadesc: &AreaDesc, images: &Images) -> bool {
     let mut fails = 0;
 
@@ -413,6 +420,14 @@ fn run_perm_with_random_fails(flash: &SimFlash, areadesc: &AreaDesc,
     fails > 0
 }
 
+#[cfg(feature = "overwrite-only")]
+#[allow(unused_variables)]
+fn run_revert_with_fails(flash: &SimFlash, areadesc: &AreaDesc, images: &Images,
+                         total_count: i32) -> bool {
+    false
+}
+
+#[cfg(not(feature = "overwrite-only"))]
 fn run_revert_with_fails(flash: &SimFlash, areadesc: &AreaDesc, images: &Images,
                          total_count: i32) -> bool {
     let mut fails = 0;
@@ -430,6 +445,13 @@ fn run_revert_with_fails(flash: &SimFlash, areadesc: &AreaDesc, images: &Images,
     fails > 0
 }
 
+#[cfg(feature = "overwrite-only")]
+#[allow(unused_variables)]
+fn run_norevert(flash: &SimFlash, areadesc: &AreaDesc, images: &Images) -> bool {
+    false
+}
+
+#[cfg(not(feature = "overwrite-only"))]
 fn run_norevert(flash: &SimFlash, areadesc: &AreaDesc, images: &Images) -> bool {
     let mut fl = flash.clone();
     let mut fails = 0;
@@ -612,6 +634,7 @@ fn try_upgrade(flash: &SimFlash, areadesc: &AreaDesc, images: &Images,
     (fl, count - c::get_flash_counter())
 }
 
+#[cfg(not(feature = "overwrite-only"))]
 fn try_revert(flash: &SimFlash, areadesc: &AreaDesc, count: usize) -> SimFlash {
     let mut fl = flash.clone();
     c::set_flash_counter(0);
@@ -624,6 +647,7 @@ fn try_revert(flash: &SimFlash, areadesc: &AreaDesc, count: usize) -> SimFlash {
     fl
 }
 
+#[cfg(not(feature = "overwrite-only"))]
 fn try_revert_with_fail_at(flash: &SimFlash, areadesc: &AreaDesc, images: &Images,
                            stop: i32) -> bool {
     let mut fl = flash.clone();
@@ -834,6 +858,16 @@ fn verify_image(flash: &Flash, offset: usize, buf: &[u8]) -> bool {
     }
 }
 
+#[cfg(feature = "overwrite-only")]
+#[allow(unused_variables)]
+// overwrite-only doesn't employ trailer management
+fn verify_trailer(flash: &Flash, offset: usize,
+                  magic: Option<&[u8]>, image_ok: Option<u8>,
+                  copy_done: Option<u8>) -> bool {
+    true
+}
+
+#[cfg(not(feature = "overwrite-only"))]
 fn verify_trailer(flash: &Flash, offset: usize,
                   magic: Option<&[u8]>, image_ok: Option<u8>,
                   copy_done: Option<u8>) -> bool {