diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index f8aaccd..cb219fa 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -29,9 +29,11 @@
 #define BOOT_LOG_LEVEL BOOT_LOG_LEVEL_ERROR
 #include <bootutil/bootutil_log.h>
 
-extern int sim_flash_erase(uint32_t offset, uint32_t size);
-extern int sim_flash_read(uint32_t offset, uint8_t *dest, uint32_t size);
-extern int sim_flash_write(uint32_t offset, const uint8_t *src, uint32_t size);
+extern int sim_flash_erase(uint8_t flash_id, uint32_t offset, uint32_t size);
+extern int sim_flash_read(uint8_t flash_id, uint32_t offset, uint8_t *dest,
+        uint32_t size);
+extern int sim_flash_write(uint8_t flash_id, uint32_t offset, const uint8_t *src,
+        uint32_t size);
 
 static jmp_buf boot_jmpbuf;
 int flash_counter;
@@ -252,41 +254,6 @@
     }
 }
 
-int hal_flash_read(uint8_t flash_id, uint32_t address, void *dst,
-                   uint32_t num_bytes)
-{
-    (void)flash_id;
-    // printf("hal_flash_read: %d, 0x%08x (0x%x)\n",
-    //        flash_id, address, num_bytes);
-    return sim_flash_read(address, dst, num_bytes);
-}
-
-int hal_flash_write(uint8_t flash_id, uint32_t address,
-                    const void *src, int32_t num_bytes)
-{
-    (void)flash_id;
-    // printf("hal_flash_write: 0x%08x (0x%x)\n", address, num_bytes);
-    // fflush(stdout);
-    if (--flash_counter == 0) {
-        jumped++;
-        longjmp(boot_jmpbuf, 1);
-    }
-    return sim_flash_write(address, src, num_bytes);
-}
-
-int hal_flash_erase(uint8_t flash_id, uint32_t address,
-                    uint32_t num_bytes)
-{
-    (void)flash_id;
-    // printf("hal_flash_erase: 0x%08x, (0x%x)\n", address, num_bytes);
-    // fflush(stdout);
-    if (--flash_counter == 0) {
-        jumped++;
-        longjmp(boot_jmpbuf, 1);
-    }
-    return sim_flash_erase(address, num_bytes);
-}
-
 void *os_malloc(size_t size)
 {
     // printf("os_malloc 0x%x bytes\n", size);
@@ -329,9 +296,7 @@
 {
     BOOT_LOG_DBG("%s: area=%d, off=%x, len=%x",
                  __func__, area->fa_id, off, len);
-    return hal_flash_read(area->fa_id,
-                          area->fa_off + off,
-                          dst, len);
+    return sim_flash_read(area->fa_device_id, area->fa_off + off, dst, len);
 }
 
 int flash_area_write(const struct flash_area *area, uint32_t off, const void *src,
@@ -339,18 +304,22 @@
 {
     BOOT_LOG_DBG("%s: area=%d, off=%x, len=%x", __func__,
                  area->fa_id, off, len);
-    return hal_flash_write(area->fa_id,
-                           area->fa_off + off,
-                           src, len);
+    if (--flash_counter == 0) {
+        jumped++;
+        longjmp(boot_jmpbuf, 1);
+    }
+    return sim_flash_write(area->fa_device_id, area->fa_off + off, src, len);
 }
 
 int flash_area_erase(const struct flash_area *area, uint32_t off, uint32_t len)
 {
     BOOT_LOG_DBG("%s: area=%d, off=%x, len=%x", __func__,
                  area->fa_id, off, len);
-    return hal_flash_erase(area->fa_id,
-                           area->fa_off + off,
-                           len);
+    if (--flash_counter == 0) {
+        jumped++;
+        longjmp(boot_jmpbuf, 1);
+    }
+    return sim_flash_erase(area->fa_device_id, area->fa_off + off, len);
 }
 
 int flash_area_read_is_empty(const struct flash_area *area, uint32_t off,
@@ -362,7 +331,7 @@
 
     BOOT_LOG_DBG("%s: area=%d, off=%x, len=%x", __func__, area->fa_id, off, len);
 
-    rc = hal_flash_read(area->fa_device_id, area->fa_off + off, dst, len);
+    rc = sim_flash_read(area->fa_device_id, area->fa_off + off, dst, len);
     if (rc) {
         return -1;
     }
diff --git a/sim/mcuboot-sys/src/api.rs b/sim/mcuboot-sys/src/api.rs
index 4e744e2..7a932a5 100644
--- a/sim/mcuboot-sys/src/api.rs
+++ b/sim/mcuboot-sys/src/api.rs
@@ -33,20 +33,20 @@
 // This isn't meant to call directly, but by a wrapper.
 
 #[no_mangle]
-pub extern fn sim_flash_erase(offset: u32, size: u32) -> libc::c_int {
+pub extern fn sim_flash_erase(_id: u8, offset: u32, size: u32) -> libc::c_int {
     let dev = unsafe { get_flash!() };
     map_err(dev.erase(offset as usize, size as usize))
 }
 
 #[no_mangle]
-pub extern fn sim_flash_read(offset: u32, dest: *mut u8, size: u32) -> libc::c_int {
+pub extern fn sim_flash_read(_id: u8, offset: u32, dest: *mut u8, size: u32) -> libc::c_int {
     let dev = unsafe { get_flash!() };
     let mut buf: &mut[u8] = unsafe { slice::from_raw_parts_mut(dest, size as usize) };
     map_err(dev.read(offset as usize, &mut buf))
 }
 
 #[no_mangle]
-pub extern fn sim_flash_write(offset: u32, src: *const u8, size: u32) -> libc::c_int {
+pub extern fn sim_flash_write(_id: u8, offset: u32, src: *const u8, size: u32) -> libc::c_int {
     let dev = unsafe { get_flash!() };
     let buf: &[u8] = unsafe { slice::from_raw_parts(src, size as usize) };
     map_err(dev.write(offset as usize, &buf))