Provide per-core thread local variables when using picolibc#2846
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keith-packard wants to merge 7 commits intoraspberrypi:developfrom
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Provide per-core thread local variables when using picolibc#2846keith-packard wants to merge 7 commits intoraspberrypi:developfrom
keith-packard wants to merge 7 commits intoraspberrypi:developfrom
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nosys.specs controls how newlib performs linking, so it's not relevant to other C libraries. Signed-off-by: Keith Packard <keithp@keithp.com>
Picolibc doesn't provide __printflike, instead it provides a more general __picolibc_format for either scanf or printf. Use that to define our own __printflike version. Signed-off-by: Keith Packard <keithp@keithp.com> Gbp-Pq: Name 0005-pico_platform_compiler-Picolibc-compatibility-fix.patch
The kitchen_sink test enables -Wredundant-decls which generates a warning about the stdout and stderr alias definitions. Disable the warning as it is incorrect in this case. Signed-off-by: Keith Packard <keithp@keithp.com>
Using -Wl,--script= hides this option from the compiler driver causing it to insert it's own linker script when it uses picolibc. Using the -T option asks it to skip adding its own. Signed-off-by: Keith Packard <keithp@keithp.com>
Picolibc may combine the preinit and init arrays into a single list, in which case it will use __bothinit_array_start and __bothinit_array_end symbols instead of the separate __preinit_array_start, __preinit_array_end and __init_array_start, __init_array_end pairs. Define both so that either method works. Signed-off-by: Keith Packard <keithp@keithp.com>
When using pico_printf_compiler with picolibc, map the various RUNTIME_INCLUDE_PRINTF_* options into the matching picolibc link flags. Signed-off-by: Keith Packard <keithp@keithp.com>
Change the linker scripts to statically allocate thread local storage space for each core and to initialize that using picolibc's _init_tls instead wedging it between .data and .bss. Implement pico-specific __aeabi_read_tp and_set_tls functions which use the core ID register at 0xd0000000 to index an array of TLS base pointers. Perform per-core TLS region setup, calling _init_tls and _set_tls using the areas allocated by the linker script. Signed-off-by: Keith Packard <keithp@keithp.com>
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will-v-pi
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| # Thread local storage static allocations, one per core | ||
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| .tls0 (NOLOAD) : { | ||
| . = ALIGN(__tls_align); | ||
| PROVIDE(__tls0_base = .); | ||
| . = . + __tls_size_align; | ||
| } > RAM | ||
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| .tls1 (NOLOAD) : { | ||
| . = ALIGN(__tls_align); | ||
| PROVIDE(__tls1_base = .); | ||
| . = . + __tls_size_align; | ||
| } > RAM | ||
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Contributor
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Would it be possible to put these sections between data and bss, so that bss and heap are contiguous? Otherwise, this may break compatibility with some other changes that are being worked on.
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Sure, but that might break code which assumes that data and bss are contiguous?
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This PR contains a single patch atop #2840 to allocate per-core thread local storage which is necessary for safe thread local variable usage (like errno).
Change the linker scripts to statically allocate thread local storage space for each core and to initialize that using picolibc's _init_tls instead wedging it between .data and .bss.
Implement pico-specific __aeabi_read_tp and_set_tls functions which use the core ID register at 0xd0000000 to index an array of TLS base pointers.
Perform per-core TLS region setup, calling _init_tls and _set_tls using the areas allocated by the linker script.