Fix embedded example and ci and remove ardupilotmega feature

[pv42]

Closed #317

Fixes for embedded:

• fix memory.x by adding _stack_end
• remove unused ardupilotmega dialect feature
• fix CI test not using linker script link.x

[joaoantoniocardoso]

I don't have a device to flash, but inspecting the built binary, all seems good:

arm-none-eabi-readelf -h target/thumbv7em-none-eabihf/release/mavlink-embedded
ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x8000195
  Start of program headers:          52 (bytes into file)
  Start of section headers:          144020 (bytes into file)
  Flags:                             0x5000400, Version5 EABI, hard-float ABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         5
  Size of section headers:           40 (bytes)
  Number of section headers:         13
  Section header string table index: 11

arm-none-eabi-objdump -h target/thumbv7em-none-eabihf/release/mavlink-embedded

target/thumbv7em-none-eabihf/release/mavlink-embedded:     file format elf32-littlearm

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .vector_table 00000194  08000000  08000000  00010000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00004328  08000194  08000194  00010194  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .rodata       00000a00  080044bc  080044bc  000144bc  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  3 .data         00000000  20000000  20000000  00014ebc  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  4 .gnu.sgstubs  00000000  08004ec0  08004ec0  00014ec0  2**5
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  5 .bss          00000004  20000000  20000000  00020000  2**2
                  ALLOC
  6 .uninit       00000000  20000004  20000004  00020000  2**2
                  ALLOC
  7 .comment      0000008b  00000000  00000000  00020000  2**0
                  CONTENTS, READONLY
  8 .ARM.attributes 00000038  00000000  00000000  0002008b  2**0
                  CONTENTS, READONLY

cargo size --release --target thumbv7em-none-eabihf -- -A
    Finished `release` profile [optimized] target(s) in 0.01s
mavlink-embedded  :
section              size        addr
.vector_table         404   0x8000000
.text               17192   0x8000194
.rodata              2560   0x80044bc
.data                   0  0x20000000
.gnu.sgstubs            0   0x8004ec0
.bss                    4  0x20000000
.uninit                 0  0x20000004
.comment              139         0x0
.ARM.attributes        56         0x0
Total               20355

[onur-ozkan]

just a nit, otherwise LGTM

[patrickelectric]

I can test on the real hardware during the weekend

[onur-ozkan]

Have you done the test, or we should just merge this? The change looks fairly good to me and it can't be more broken than the status quo.

[patrickelectric]

I just lost my board, no idea where it's 🫤