On 2/8/21 9:22 PM, Peter Maydell wrote: > On Mon, 8 Feb 2021 at 20:04, Philippe Mathieu-Daudé <f4...@amsat.org> wrote: >> >> We want to be able to use the 'SH4' config for architecture >> specific features. As CONFIG_SH4 is only used to select >> peripherals, rename it CONFIG_SH4_DEVICES. >> >> Reviewed-by: Alex Bennée <alex.ben...@linaro.org> >> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> >> --- >> hw/block/meson.build | 2 +- >> hw/char/meson.build | 2 +- >> hw/intc/meson.build | 2 +- >> hw/sh4/Kconfig | 6 +++--- >> hw/timer/meson.build | 2 +- >> 5 files changed, 7 insertions(+), 7 deletions(-) > > We could if we wished be more fine-grained about this, eg by > adding new CONFIG options for each device: > CONFIG_TC58128 > CONFIG_SH_SERIAL > CONFIG_SH_INTC > CONFIG_SH_TIMER > CONFIG_SH_PCI > > and then in hw/sh4/Kconfig > * config SH7750: > add 'select SH_SERIAL', 'select SH_INTC', 'select SH_TIMER' > * config R2D: > add 'select SH7750' (it's a pre-existing bug that it doesn't, since > r2d.c has a call to sh7750_init(). Harmless at the moment because > nothing actually uses CONFIG_SH7750 -- hw/sh4/meson.build always > compiles sh7750.c and sh7750_regnames.c unconditionally...) > add 'select SH_PCI' (and make hw/sh4/meson.build build sh_pci.c > only if it is set...) > * config SHIX > add 'select TC58128'
OK. > Do we have a general preference for how fine-grained we go with the > Kconfig switches ? Looking at the arm code, in some cases we have > a CONFIG_ for the SoC that uses 'select' to turn on a separate > CONFIG_ for each device (the STM32 SoCs are done this way), and > in some cases we just have the meson.build use the SoC's CONFIG_* > to control whether we compile its devices (the Xilinx and Exynos4 > SoCs are done this way). When reviewing new code it would be helpful > to know whether to suggest doing it one way or the other :-) My view is: - Use fine granularity with shared/reusable models, so if someone wants to build a QEMU for a single machine, it is possible (using --without-default-devices and a specific target config.mak). Example: STM32F205_SOC and STM32F405_SOC - For some (family of) SoC, a single switch is acceptable. In particular when all models are implemented in the same source file. Example: ASPEED_SOC - Do not look at hw/i386/Kconfig I have an old branch where I was generating a .dot of the Kconfig tree for easier visualization, fine granularity was helpful. I'll try to update it. Regards, Phil.
