add instructions for using edbg to program FLASH

.cargo/config

@@ -1,7 +1,7 @@
 [target.thumbv8m.base-none-eabi]
 runner = 'arm-none-eabi-gdb'
 rustflags = [
-  "-C", "link-arg=-Tram.x",
+  "-C", "link-arg=-Tlink.x",
 ]
 
 [build]

README.md

@@ -12,25 +12,37 @@ naming convention used.
 
 https://github.com/japaric/xargo/pull/226
 
-It makes use of changes to `cortex-m-rt` and `cortex-m-semihosting`
-which have not yet been merged upstream.
+## Usage
 
-By default the linker is configured to run everything out of RAM,
-I have not yet managed to program the flash on this chip.
+### Building the blink example
 
-For help enabling executable RAM or more hints at how to program the flash see:
+```
+RUST_TARGET_PATH=`pwd` xargo build --release --target thumbv8m.base-none-eabi --example blink
+```
 
-https://github.com/dwelch67/atsaml11_samples/tree/master/ATSAML11
+### Programming blink example to FLASH on the SAM L11 XPLAINED dev board
 
-## Usage
+First build and install [edbg](https://github.com/ataradov/edbg), SAM L11
+support was recently added.
 
-### Building the blink example
+After building per the above section:
 
 ```
-RUST_TARGET_PATH=`pwd` xargo build --release --target thumbv8m.base-none-eabi --example blink
+arm-none-eabi-objcopy target/thumbv8m.base-none-eabi/release/examples/blink target/thumbv8m.base-none-eabi/release/examples/blink.bin -O binary
+edbg -t mchp_cm23 -e -p -f target/thumbv8m.base-none-eabi/release/examples/blink.bin
 ```
 
-### Running blink example on the SAM L11 XPLAINED dev board
+### Running blink example out of RAM on the SAM L11 XPLAINED dev board
+
+This requires RAM to be marked as executable, for help doing this see:
+https://github.com/dwelch67/atsaml11_samples/tree/master/ATSAML11
+
+You will want to edit `.cargo/config`, change `rustflags` as follows, then rebuild.
+```
+rustflags = [
+  "-C", "link-arg=-Tram.x",
+]
+```
 
 This seems to only work with openocd 0.9, in one window run:
 ```

memory.x

@@ -1,6 +1,6 @@
 /* atsaml11e16 */
 MEMORY
 {
-    FLASH : ORIGIN = 0x08000000, LENGTH = 64K
+    FLASH : ORIGIN = 0x00000000, LENGTH = 64K
     RAM : ORIGIN = 0x20000000, LENGTH = 16K
 }