Conversation
Store up to 32 reflow profiles in flash sector 7 (8KB at 0xE000). The linker splits firmware across MFlash_Lo (sectors 0-6, 56KB) and MFlash_Hi (sectors 8-10, 64KB) for 120KB total firmware space. Uses cache-erase-rewrite pattern with ~3.7KB static BSS cache. IAP calls use correct sector 7 (not nonexistent sector 19 as before). Serial commands: save flash, delete flash, list flash, backup. All commands identical to the v2.1.0 interface.
Sector 7 split failed: MFlash_Hi was 64KB, firmware is 94KB. Sector 10 works but only gives 96KB firmware. Sector 1 (0x2000-0x3FFF, 8KB) is optimal: - MFlash_Vec (sector 0, 8KB): vectors, section table, CRP, startup - Sector 1: 32 profile slots × 256 bytes - MFlash_Code (sectors 2-10, 112KB): main .text, .rodata, .data LMA Firmware gets 120KB total. 94KB code fits in 112KB MFlash_Code with 18KB to spare.
The IAP write was failing because iap_prepare_sector() was a separate function that re-enabled IRQs after prepare. Any interrupt between prepare and the copy/erase would invalidate the preparation. Now prepare and execute happen in a single IRQ-disabled critical section for both erase and write operations. Also fixed rewrite_sector to return -1 when the target slot write fails, so the caller correctly reports errors.
Print NXP IAP status codes on failure: 0=OK, 7=INVALID_SECTOR, 8=NOT_BLANK, 9=NOT_PREPARED, etc. Also shows sector number and base address at init.
The LPC2134 IAP ROM uses 0x40003FE0-0x40003FFF to store state (e.g. which sector is prepared). The stack started at 0x40004000 and grew down into this area, overwriting the IAP's 'sector prepared' state between prepare and copy calls — causing IAP code 9 (SECTOR_NOT_PREPARED_FOR_WRITE_OPERATION). Fix: shrink Ram16 by 32 bytes so the stack top is 0x40003FE0, keeping the IAP workspace safe.
Previous 32-byte reservation was insufficient. UM10120 states: 'The top 256 bytes of on-chip RAM are reserved and used by the ISP/IAP handler' for LPC2131/32/34/36/38. Stack top moves from 0x40003FE0 to 0x40003F00, fully clearing the IAP workspace at 0x40003F00-0x40003FFF.
UM10120: 'When flash programming is performed, it is recommended that MAM be disabled.' The MAM caches flash reads and interferes with IAP flash programming. Save MAMCR, set to 0 (disabled) before IAP, restore after.
The IAP ROM uses 128 bytes of the caller's stack internally. With command[5] and result[3] on the stack, the IAP's own stack frame could overwrite them before reading all parameters. Moving to static BSS ensures they're in a safe, fixed location.
If IAP works with sector 10 but not sector 1, the issue is lpc21isp interference with sector 1. If sector 10 also fails, the IAP calling convention is the problem.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Store up to 32 reflow profiles in flash sector 7 (8KB at 0xE000). The linker splits firmware across MFlash_Lo (sectors 0-6, 56KB) and MFlash_Hi (sectors 8-10, 64KB) for 120KB total firmware space.
Uses cache-erase-rewrite pattern with ~3.7KB static BSS cache. IAP calls use correct sector 7 (not nonexistent sector 19 as before).
Serial commands: save flash, delete flash, list flash, backup. All commands identical to the v2.1.0 interface.