armcc - remove fromelf output before regenerating one

[tung7970]

Description

Fix armcc recompile errors during elf2bin stage. Errors shown as follows:

Elf2Bin: mbed-os-example-wifi
Error: Q0147E: Failed to create Directory .\BUILD\REALTEK_RTL8195AM\ARM\mbed-os-example-wifi.bin\IMAGE2_TABLE: File exists
Finished: 0 information, 0 warning and 1 error messages.
[ERROR] Error: Q0147E: Failed to create Directory .\BUILD\REALTEK_RTL8195AM\ARM\mbed-os-example-wifi.bin\IMAGE2_TABLE: File exists
Finished: 0 information, 0 warning and 1 error messages.

Fix issue #6306

Pull request type

• Fix
• Refactor
• New target
• Feature
• Breaking change

[0xc0170]

This is related, similar change that resulted in this issue #5537 , see #5021

In the issue 6306:

I personally prefer option 2 since it solves the problem and also makes armcc behave like the rest

How is it with rest ? IAR and GCC ARM?

[samchuarm]

@ARMmbed/team-realtek

[theotherjimmy]

Excerpts from prior PRs that proposed the same change:

Typically when there are multiple LRs and building creates a directory rather than a binary it indicates something is wrong in the scatter file. Adding this change may mask scatter file errors. Rather than having an obvious error at compile time, a binary will be created that does not work.

It looks like the LPC4088_DM's post build hook makes use of multiple regions being created if the binary is big enough. It does this by manually combining the regions with little padding (up to 512K). With this PR padding is done automatically, but rather than 512K it pads the entire address space from LR_IROM1 to LR_IROM which is ~640MB.

How do you plan on correcting that behavior for the LPC4088_DM? How do you plan on making this change in a way that is backwards compatible? Could using a .hex file be a viable workaround?

[samchuarm]

Hi @tung7970 could you please help comment on @0xc0170 @theotherjimmy questions? Thanks.

[tung7970]

@0xc0170 So far, only ARMCC creates directory if there are multiple load regions.
@theotherjimmy The other solution is to remove output file/directory before regenerating one. Please see the revised patch. This should be backward compatible and target independent.

[theotherjimmy]

Looks good. Thanks!

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 1496
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/6344/

Triggering tests

/morph test
/morph uvisor-test
/morph export-build
/morph mbed2-build

[mbed-ci]

Exporter Build : SUCCESS

Build number : 1140
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/6344/

[mbed-ci]

Test : SUCCESS

Build number : 1279
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/6344/1279