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authorJeremy Compostella <jeremy.compostella@intel.com>2022-12-01 15:07:51 -0700
committerMartin L Roth <gaumless@gmail.com>2022-12-17 20:51:38 +0000
commit50139d00bd5fdec1764c80fda846ecc1efcbfa5d (patch)
treee2123610aa0e33e879c0b523ca23c4474d7b9545 /src/drivers/uart/Makefile.inc
parentfa83887e48f196cfa303ce6de32acf1dfec7cad9 (diff)
lib: Hook up libhwbase in romstage
It's hidden behind the configuration option `CONFIG_ROMSTAGE_LIBHWBASE'. This also adds some glue code to use the coreboot console for debug output and our monotonic timer framework as timer backend. Running Ada code in romstage and more particular libhwbase brings a few challenges as global initialized variables are not supported in Cache-As-Ram mode. 1. The libhwbase dynamic mmio driver implementation makes the Gnat compiler generate some global initialized variables. For this reason, when compiled for romstage or for romstage and ramstage the static mmio driver is enforced (`HWBASE_STATIC_MMIO'). 2. The Gnat compiler generates elaboration functions to initialize program data at runtime. These elaboration functions are called by the romstage_adainit() function. The data references symbols suffixed by `_E'. Even though these symbols, at compilation time, do not contain any data and are filled with zeros, the Gnat compiler installs them in the .data section. Since these symbols are actually filled with zeros, it is safe to install them in the .bss section. cf. https://docs.adacore.com/gnat_ugn-docs/html/gnat_ugn/gnat_ugn/elaboration_order_handling_in_gnat.html#elaboration-code This patch requires the libhwbase https://review.coreboot.org/c/libhwbase/+/69854 CL. BUG=b:252792591 BRANCH=firmware-brya-14505.B TEST=libhwbae compiles for romstage and loads successfully Change-Id: I670249d33506e886a683e55d1589cb2bf9b16aa3 Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/70275 Reviewed-by: Boris Mittelberg <bmbm@google.com> Reviewed-by: Nick Vaccaro <nvaccaro@google.com> Reviewed-by: Tarun Tuli <taruntuli@google.com> Reviewed-by: Zhixing Ma <zhixing.ma@intel.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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