altos/micropeak-v2: Erase log space at end of BOOST_DELAY

We have to erase the log before the flight starts, so this seems like
the latest possible moment.

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

1 files changed, 15 insertions, 0 deletions

diff --git a/src/stmf0/ao_storage_stm.c b/src/stmf0/ao_storage_stm.c
index 17c934a5..c6f1defe 100644
--- a/src/stmf0/ao_storage_stm.c
+++ b/src/stmf0/ao_storage_stm.c
@@ -127,9 +127,24 @@ _ao_flash_write(uint32_t pos, void *sv, uint16_t len)
 	stm_flash.cr &= ~(1 << STM_FLASH_CR_PG);
 }
 
+static bool
+ao_storage_is_erased(uint32_t pos)
+{
+	uint16_t *flash = _ao_flash_addr(pos);
+	uint32_t i = ao_storage_block >> 1;
+
+	while (i--)
+		if (*flash++ != 0xffff)
+			return false;
+	return true;
+}
+
 uint8_t
 ao_storage_erase(uint32_t pos)
 {
+	if (ao_storage_is_erased(pos))
+		return 1;
+
 	ao_arch_block_interrupts();
 	ao_flash_unlock();