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| author | Georg-Johann Lay <avr@gjlay.de> | 2024-02-12 11:10:48 +0100 |
|---|---|---|
| committer | Georg-Johann Lay <avr@gjlay.de> | 2024-02-12 12:03:11 +0100 |
| commit | 525cfe1e9554858366e7811aa9e437357c0f272e (patch) | |
| tree | 2139ea6c99d54e13ab507a007b547469903f49e6 | |
| parent | 1e3f78dbb328a2f2db8def241372cb947d9cb7eb (diff) | |
| download | gcc-525cfe1e9554858366e7811aa9e437357c0f272e.zip gcc-525cfe1e9554858366e7811aa9e437357c0f272e.tar.gz gcc-525cfe1e9554858366e7811aa9e437357c0f272e.tar.bz2 | |
AVR: target/112944 - Addendum: Link code to initialize NVMCTRL_CTRLB.FLMAP
For devices that see a part for the flash memory in the RAM address space,
bit-field NVMCTRL_CTRLB.FLMAP must match the value of symbol __flmap.
This is achieved by dragging in startup code from lib<mcu>.a.
The mechanism is the same like for libgcc's __do_copy_data and __do_clear_bss.
The code is implemented in AVR-LibC #931 and can be dragged by referencing
__do_flmap_init.
In addition to setting FLMAP, that code also sets bit FLMAPLOCK provided
symbol __flmap_lock has a non-zero value. This protects FLMAP from future
changes.
When the __do_flmap_init code is not wanted, the symbol can be satisfied by
linking with -Wl,--defsym,__do_flmap_init=0
gcc/
PR target/112944
* config/avr/gen-avr-mmcu-specs.cc (print_mcu) [have_flmap]:
<*link_rodata_in_ram>: Spec undefs symbol __do_flmap_init
when not linked with -mrodata-in-ram.
| -rw-r--r-- | gcc/config/avr/gen-avr-mmcu-specs.cc | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/gcc/config/avr/gen-avr-mmcu-specs.cc b/gcc/config/avr/gen-avr-mmcu-specs.cc index ea69145..bb94bea 100644 --- a/gcc/config/avr/gen-avr-mmcu-specs.cc +++ b/gcc/config/avr/gen-avr-mmcu-specs.cc @@ -369,7 +369,10 @@ print_mcu (const avr_mcu_t *mcu, const McuInfo &mi) } // -m[no-]rodata-in-ram affects linking. Sanity check its usage. - fprintf (f, "*link_rodata_in_ram:\n\t%%(check_rodata_in_ram)\n\n"); + fprintf (f, "*link_rodata_in_ram:\n\t%%(check_rodata_in_ram)"); + if (mi.is_device && mi.have_flmap) + fprintf (f, " %%{!mrodata-in-ram:-u __do_flmap_init}"); + fprintf (f, "\n\n"); // Specs known to GCC. |