bartoszek/zephyr
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

arch: riscv: Introduce code model options

Browse Source 
This commit introduces a new Kconfig choice for configuring the code model
used for compilation.

All three code models specified by the RISC-V ELF psABI specification are
supported: medlow, medany and large.

For RV32, the `medlow` code model is always selected.
For RV64, the `large` code model is selected if the SRAM or kernel VM base
address is greater than or equal to 4 GiB; otherwise, the `medany` code
model is selected.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit is contained in:
Stephanos Ioannidis 2025-07-03 14:40:14 +09:00 committed by Anas Nashif
parent f5000936a8
commit dc3c9f3560
2 changed files with 48 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
arch/riscv/Kconfig
View File

@ -53,6 +53,34 @@ config RISCV_ALWAYS_SWITCH_THROUGH_ECALL
and most people should say n here to minimize context switching
overhead.
choice RISCV_CMODEL
prompt "RISC-V Code Model"
default RISCV_CMODEL_LARGE if (SRAM_BASE_ADDRESS > 0xffffffff) || \
(KERNEL_VM_BASE > 0xffffffff)
default RISCV_CMODEL_MEDANY if 64BIT
default RISCV_CMODEL_MEDLOW
config RISCV_CMODEL_MEDLOW
bool "Medium-low code model"
help
In medium-low code model (medlow), the program and its statically defined symbols must lie
within a single 2 GiB address range and between absolute addresses -2 GiB and +2 GiB.
config RISCV_CMODEL_MEDANY
bool "Medium-any code model"
help
In medium-any code model (medany), the program and its statically defined symbols must be
within any single 2 GiB address range. The code generated by this model is
position-independent.
config RISCV_CMODEL_LARGE
bool "Large code model"
help
In large code model (large), the program and its statically defined symbols have no
restrictions on size and placement.
endchoice
choice RISCV_SMP_IPI_IMPL
prompt "RISC-V SMP IPI implementation"
depends on SMP

24
cmake/compiler/gcc/target_riscv.cmake
View File

@ -3,11 +3,17 @@
set(riscv_mabi "lp")
set(riscv_march "rv")
if(CONFIG_RISCV_CMODEL_MEDLOW)
set(riscv_mcmodel "medlow")
elseif(CONFIG_RISCV_CMODEL_MEDANY)
set(riscv_mcmodel "medany")
elseif(CONFIG_RISCV_CMODEL_LARGE)
set(riscv_mcmodel "large")
endif()
if(CONFIG_64BIT)
string(CONCAT riscv_mabi ${riscv_mabi} "64")
string(CONCAT riscv_march ${riscv_march} "64")
list(APPEND TOOLCHAIN_C_FLAGS -mcmodel=medany)
list(APPEND TOOLCHAIN_LD_FLAGS -mcmodel=medany)
else()
string(CONCAT riscv_mabi "i" ${riscv_mabi} "32")
string(CONCAT riscv_march ${riscv_march} "32")
@ -123,8 +129,17 @@ if(NOT CONFIG_RISCV_ISA_EXT_M AND
string(CONCAT riscv_march ${riscv_march} "_zmmul")
endif()
list(APPEND TOOLCHAIN_C_FLAGS -mabi=${riscv_mabi} -march=${riscv_march})
list(APPEND TOOLCHAIN_LD_FLAGS NO_SPLIT -mabi=${riscv_mabi} -march=${riscv_march})
list(APPEND TOOLCHAIN_C_FLAGS
-mabi=${riscv_mabi}
-march=${riscv_march}
-mcmodel=${riscv_mcmodel}
)
list(APPEND TOOLCHAIN_LD_FLAGS NO_SPLIT
-mabi=${riscv_mabi}
-march=${riscv_march}
-mcmodel=${riscv_mcmodel}
)
# Flags not supported by llext linker
# (regexps are supported and match whole word)
@ -146,6 +161,7 @@ set(LLEXT_REMOVE_FLAGS
set(LLEXT_APPEND_FLAGS
-mabi=${riscv_mabi}
-march=${riscv_march}
-mcmodel=${riscv_mcmodel}
-mno-relax
-msmall-data-limit=0
)