altos/samd21: Automatically erase flash when writing

Need to erase pages before writing them.

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

diff --git a/src/samd21/ao_flash_samd21.c b/src/samd21/ao_flash_samd21.c
index c1cee3f876e75e95b493e24866cd41e48a8cfee9..b0d91c5cdee2e1f482880907cdbf5eea0475661f 100644 (file)
--- a/src/samd21/ao_flash_samd21.c
+++ b/src/samd21/ao_flash_samd21.c
@@ -101,6 +101,9 @@ ao_flash_erase_page(uint32_t *page)
        uint32_t row_size = samd21_nvmctrl_row_size();
        uint32_t rows = (row_size + 255) / 256;
 
+       if ((uintptr_t) page & (row_size - 1))
+               return;
+
        ao_arch_block_interrupts();
 
        if (((uintptr_t) row & (row_size - 1)) == 0) {
@@ -121,6 +124,8 @@ ao_flash_page(uint32_t *page, uint32_t *src)
        uint32_t        i;
        uint32_t        per_page = page_size / sizeof(uint32_t);
 
+       ao_flash_erase_page(page);
+
        ao_arch_block_interrupts();
 
        while(pages--) {