diff options
author | Randall Spangler <rspangler@chromium.org> | 2013-05-17 13:12:01 -0700 |
---|---|---|
committer | ChromeBot <chrome-bot@google.com> | 2013-05-22 19:15:56 -0700 |
commit | e8ecda5e8d0384ddc8fe6b3bd9e991ee6d84faae (patch) | |
tree | 402184e035d6e792ccfa41fbdf4caf9b9c8abece /include/flash.h | |
parent | 6592036c6c6b24744ac3bb1450ee41f0c7630b10 (diff) | |
download | chrome-ec-e8ecda5e8d0384ddc8fe6b3bd9e991ee6d84faae.tar.gz |
Support flash write protect on STM32L
This adds support for write protecting the RO code at boot, and the
entire flash on demand.
Implementation if WP# is not asserted is currently a little different
than STM32F and LM4; RO is still protected at boot if ro_at_boot, but
can be unprotected and the change will commit on the next reboot.
This saves the bank of flash which we use for pstate on LM4 and
STM32F. I think I can use one of the unused option bits (WRP2 bit 0)
to hold the RO-at-boot flag, in which case I can more closely match
the behavior of the other chips, but I'd like to do that (or give up
and implement pstate) in a separate CL so it's clearer what I'm doing.
BUG=chrome-os-partner:15613
BRANCH=none
TEST=manual
- flashinfo -> (no flags)
- enable WP (via screw or dut-control)
- flashinfo -> wp_gpio_asserted
- flashwp enable
- flashinfo -> wp_gpio_asserted ro_at_boot
- flashwp now
- flashinfo -> wp_gpio_asserted ro_at_boot all_now
- flashwp disable -> fails
- flashinfo -> wp_gpio_asserted ro_at_boot all_now
- flasherase 0x1fc00 0x400 -> fails
- reboot
- flashinfo -> wp_gpio_asserted ro_at_boot ro_now
- flasherase 0xfc00 0x400 -> fails
- flasherase 0x1fc00 0x400 -> succeeds
- disable WP (via screw or dut-control)
- reboot
- flashinfo -> ro_at_boot ro_now
- flashwp disable
- flashinfo -> ro_now
- reboot
- flashinfo -> (no flags)
- flasherase 0xfc00 0x400 -> succeeds
- flasherase 0x1fc00 0x400 -> succeeds
Change-Id: Id1b6b099a44a1985a5ab9387feb882a8f26e3aa1
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/55594
Diffstat (limited to 'include/flash.h')
-rw-r--r-- | include/flash.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/flash.h b/include/flash.h index 9a9454bf52..fe592e3478 100644 --- a/include/flash.h +++ b/include/flash.h @@ -70,6 +70,17 @@ int flash_physical_erase(int offset, int size); */ int flash_physical_get_protect(int bank); +/** + * Force reload of flash protection bits. + * + * Some EC architectures (STM32L) only load the bits from option bytes at + * power-on reset or via a special command. This issues that command if + * possible, which triggers a power-on reboot. + * + * Only returns (with EC_ERROR_ACCESS_DENIED) if the command is locked. + */ +int flash_physical_force_reload(void); + /*****************************************************************************/ /* High-level interface for use by other modules. */ |