diff options
Diffstat (limited to 'cmd/sbc_harness/static/Documentation/harness_flash_bin.txt')
| -rw-r--r-- | cmd/sbc_harness/static/Documentation/harness_flash_bin.txt | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt b/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt index 982d7e0..115f2ee 100644 --- a/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt +++ b/cmd/sbc_harness/static/Documentation/harness_flash_bin.txt @@ -7,6 +7,10 @@ DESCRIPTION Any number of readers may read the flash contents. + Only one writer can have the file open at a time; once the + file is closed, the harness reboots into the new firmware. + Writes to the top half of the chip will fail. + BUGS - The size of the chip is configured at compile-time. If the firmware is loaded onto hardware with a larger flash chip @@ -16,8 +20,13 @@ BUGS compiled for, then accessing the missing upper part of the chip will crash. - - This file is not writable; it aught to be possible to update - the harness firmware by writing to this file. + - When writing to the flash using this file, only half of the + chip capacity is usable; the top half and bottom half are + mirrors of each-other. This is to avoid the firmware + crashing as its program text is overwritten; the firmware is + executing out of the bottom half, and writing to the top + half; once the file is closed, a minimal in-RAM function + copies the top half to the bottom half and reboots. AUTHOR Copyright (C) 2025 Luke T. Shumaker <lukeshu@lukeshu.com> |