From cbff1483ae7469d3961341a1cfdfeb8b4bb557c1 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sun, 6 Nov 2022 15:09:55 -0800 Subject: [PATCH] samd21: Avoid divides in boot loader The divide code is huge and overflows flash. Signed-off-by: Keith Packard --- src/samd21/ao_flash_samd21.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/src/samd21/ao_flash_samd21.c b/src/samd21/ao_flash_samd21.c index b0d91c5c..502ff35e 100644 --- a/src/samd21/ao_flash_samd21.c +++ b/src/samd21/ao_flash_samd21.c @@ -38,7 +38,15 @@ samd21_nvmctrl_lock_region(void) static uint8_t ao_flash_lock_region_bit(void *addr) { - return (uint8_t) (((uintptr_t) addr) / samd21_nvmctrl_lock_region()); + uint32_t lock_region = samd21_nvmctrl_lock_region(); + uintptr_t a = (uintptr_t) addr; + + while (lock_region) { + a >>= 1; + lock_region >>= 1; + } + + return (uint8_t) a; } static uint8_t @@ -119,10 +127,10 @@ ao_flash_erase_page(uint32_t *page) void ao_flash_page(uint32_t *page, uint32_t *src) { - uint32_t page_size = samd21_nvmctrl_page_size(); - uint32_t pages = 256 / page_size; + uint32_t page_shift = samd21_nvmctrl_page_shift(); + uint32_t pages = 256 >> page_shift; uint32_t i; - uint32_t per_page = page_size / sizeof(uint32_t); + uint32_t per_page = 1 << (page_shift - 2); ao_flash_erase_page(page); -- 2.30.2