altos/stmf0: Add a comment about the requirements for using ao_flash_stm

Need HSI clock and the flashing functions loaded in ram.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/stmf0/ao_flash_stm.c b/src/stmf0/ao_flash_stm.c
index ef2e261909574d8d8715ac850dc615f0a35f9263..2d57eea72701eefeae6e61ad0a6fc0395cf2dac7 100644 (file)
--- a/src/stmf0/ao_flash_stm.c
+++ b/src/stmf0/ao_flash_stm.c
@@ -19,6 +19,12 @@
 #include <ao.h>
 #include <ao_flash.h>
 
+/* Note that the HSI clock must be running for this code to work.
+ * Also, special care must be taken with the linker to ensure that the
+ * functions marked 'ramtext' land in ram and not rom. An example of that
+ * can be found in altos-loader.ld
+ */
+
 static uint8_t
 ao_flash_is_locked(void)
 {