Xen project Mailing List

Re: [PATCH] arm: Drop deprecated early printk platform options

To: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>

From: Michal Orzel <michal.orzel@xxxxxxx>

Date: Fri, 13 Sep 2024 09:28:45 +0200

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Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>

Delivery-date: Fri, 13 Sep 2024 07:29:19 +0000

List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

Hi Bertrand, On 13/09/2024 08:54, Bertrand Marquis wrote: > > > Hi Michal, > >> On 13 Sep 2024, at 08:15, Michal Orzel <michal.orzel@xxxxxxx> wrote: >> >> The predefined configurations for early printk have been deprecated for >> a sufficient amount of time. Let's finally remove them. >> >> Note: >> In order not to loose these predefined configurations, I wrote a wiki >> page: https://wiki.xenproject.org/wiki/Xen_on_ARM_Early_Printk >> >> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx> >> --- >> docs/misc/arm/early-printk.txt | 4 - >> xen/arch/arm/Kconfig.debug | 155 ++------------------------------- >> 2 files changed, 9 insertions(+), 150 deletions(-) >> >> diff --git a/docs/misc/arm/early-printk.txt b/docs/misc/arm/early-printk.txt >> index bc2d65aa2ea3..e6b9124a38e3 100644 >> --- a/docs/misc/arm/early-printk.txt >> +++ b/docs/misc/arm/early-printk.txt >> @@ -35,8 +35,4 @@ Other options depends on the driver selected: >> >> - For all other uarts there are no additional options. >> >> -As a convenience it is also possible to select from a list of >> -predefined configurations available in the list of choice for "Early >> -printk" for specific platform. >> - >> By default early printk is disabled. >> diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug >> index eec860e88e0b..2fa0acd2a3f1 100644 >> --- a/xen/arch/arm/Kconfig.debug >> +++ b/xen/arch/arm/Kconfig.debug >> @@ -13,177 +13,67 @@ choice >> Choose one of the UART drivers for early printk, then you'll >> have to specify the parameters, like the base address. >> >> - Deprecated: Alternatively, there are platform specific options >> - which will have default values for the various parameters. But >> - such option will soon be removed. >> - >> config EARLY_UART_CHOICE_8250 >> select EARLY_UART_8250 >> bool "Early printk via 8250 UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a 8250 UART. You can use this option to >> - provide the parameters for the 8250 UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a 8250 UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_CADENCE >> select EARLY_UART_CADENCE >> depends on ARM_64 >> bool "Early printk via Cadence UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a Cadence UART. You can use this option to >> - provide the parameters for the Cadence UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a Cadence UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_EXYNOS4210 >> select EARLY_UART_EXYNOS4210 >> depends on ARM_32 >> bool "Early printk via Exynos4210 UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a Exynos 4210 UART. You can use this option to >> - provide the parameters for the Exynos 4210 UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a Exynos 4210 UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_IMX_LPUART >> select EARLY_UART_IMX_LPUART >> depends on ARM_64 >> bool "Early printk via i.MX LPUART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a i.MX LPUART. You can use this option to >> - provide the parameters for the i.MX LPUART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a i.MX LPUART. >> + >> config EARLY_UART_CHOICE_MESON >> select EARLY_UART_MESON >> depends on ARM_64 >> bool "Early printk via MESON UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a MESON UART. You can use this option to >> - provide the parameters for the MESON UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a MESON UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_MVEBU >> select EARLY_UART_MVEBU >> depends on ARM_64 >> bool "Early printk via MVEBU UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a MVEBU UART. You can use this option to >> - provide the parameters for the MVEBU UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a MVEBU UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_PL011 >> select EARLY_UART_PL011 >> bool "Early printk via PL011 UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a PL011 UART. You can use this option to >> - provide the parameters for the PL011 UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a PL011 UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> config EARLY_UART_CHOICE_SCIF >> select EARLY_UART_SCIF >> bool "Early printk via SCIF UART" >> help >> Say Y here if you wish the early printk to direct their >> - output to a SCIF UART. You can use this option to >> - provide the parameters for the SCIF UART rather than >> - selecting one of the platform specific options below if >> - you know the parameters for the port. >> + output to a SCIF UART. >> >> - This option is preferred over the platform specific >> - options; the platform specific options are deprecated >> - and will soon be removed. >> - >> - config EARLY_PRINTK_BRCM >> - bool "Early printk with 8250 on Broadcom 7445D0 boards with A15 processors" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_DRA7 >> - bool "Early printk with 8250 on DRA7 platform" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_EXYNOS5250 >> - bool "Early printk with the second UART on Exynos5250" >> - select EARLY_UART_EXYNOS4210 >> - depends on ARM_32 >> - config EARLY_PRINTK_FASTMODEL >> - bool "Early printk with pl011 on ARM Fastmodel software emulators" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_HIKEY960 >> - bool "Early printk with pl011 with Hikey 960" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_JUNO >> - bool "Early printk with pl011 on Juno platform" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_LAGER >> - bool "Early printk with SCIF0 on Renesas Lager board (R-Car H2 processor)" >> - select EARLY_UART_SCIF >> - config EARLY_PRINTK_MIDWAY >> - bool "Early printk with pl011 on Calxeda Midway processors" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_MVEBU >> - bool "Early printk with MVEBU for Marvell Armada 3700 SoCs" >> - select EARLY_UART_MVEBU >> - depends on ARM_64 >> - config EARLY_PRINTK_OMAP5432 >> - bool "Early printk with UART3 on TI OMAP5432 processors" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_RCAR3 >> - bool "Early printk with SCIF2 on Renesas R-Car Gen3 processors" >> - select EARLY_UART_SCIF >> - config EARLY_PRINTK_SEATTLE >> - bool "Early printk with pl011 for AMD Seattle processor" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_SUN6I >> - bool "Early printk with 8250 on Allwinner A31 processors" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_SUN7I >> - bool "Early printk with 8250 on Allwinner A20 processors" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_THUNDERX >> - bool "Early printk with pl011 for Cavium ThunderX processor" >> - select EARLY_UART_PL011 >> - depends on ARM_64 >> - config EARLY_PRINTK_VEXPRESS >> - bool "Early printk with pl011 for versatile express" >> - select EARLY_UART_PL011 >> - config EARLY_PRINTK_XGENE_MCDIVITT >> - bool "Early printk with 820 on Xgene mcdivitt platform" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_XGENE_STORM >> - bool "Early printk with 820 on Xgene storm platform" >> - select EARLY_UART_8250 >> - config EARLY_PRINTK_ZYNQMP >> - bool "Early printk with Cadence UART for Xilinx ZynqMP SoCs" >> - select EARLY_UART_CADENCE >> - depends on ARM_64 >> endchoice >> >> >> @@ -219,25 +109,6 @@ config EARLY_UART_BASE_ADDRESS >> depends on EARLY_PRINTK >> hex "Early printk, physical base address of debug UART" >> range 0x0 0xffffffff if ARM_32 >> - default 0xF040AB00 if EARLY_PRINTK_BRCM >> - default 0x4806A000 if EARLY_PRINTK_DRA7 >> - default 0x1c090000 if EARLY_PRINTK_FASTMODEL >> - default 0x12c20000 if EARLY_PRINTK_EXYNOS5250 >> - default 0xfff32000 if EARLY_PRINTK_HIKEY960 >> - default 0x7ff80000 if EARLY_PRINTK_JUNO >> - default 0xe6e60000 if EARLY_PRINTK_LAGER >> - default 0xfff36000 if EARLY_PRINTK_MIDWAY >> - default 0xd0012000 if EARLY_PRINTK_MVEBU >> - default 0x48020000 if EARLY_PRINTK_OMAP5432 >> - default 0xe6e88000 if EARLY_PRINTK_RCAR3 >> - default 0xe1010000 if EARLY_PRINTK_SEATTLE >> - default 0x01c28000 if EARLY_PRINTK_SUN6I >> - default 0x01c28000 if EARLY_PRINTK_SUN7I >> - default 0x87e024000000 if EARLY_PRINTK_THUNDERX >> - default 0x1c090000 if EARLY_PRINTK_VEXPRESS >> - default 0x1c021000 if EARLY_PRINTK_XGENE_MCDIVITT >> - default 0x1c020000 if EARLY_PRINTK_XGENE_STORM >> - default 0xff000000 if EARLY_PRINTK_ZYNQMP > > Shouldn't we put a default 0 value here ? No, we should not. It's done like that on purpose to trigger build error if user enables early printk but forgets to specify an address. Adding default 0 would remove this guard behavior. > >> >> config EARLY_UART_PL011_BAUD_RATE >> depends on EARLY_UART_PL011 >> @@ -250,7 +121,6 @@ config EARLY_UART_PL011_BAUD_RATE >> not try to initialize the UART, so that bootloader or firmware >> settings can be used for maximum compatibility. >> >> - default 115200 if EARLY_PRINTK_FASTMODEL >> default 0 >> >> config EARLY_UART_PL011_MMIO32 >> @@ -274,13 +144,6 @@ config EARLY_UART_8250_REG_SHIFT >> >> Default to 0. >> >> - default 2 if EARLY_PRINTK_BRCM >> - default 2 if EARLY_PRINTK_DRA7 >> - default 2 if EARLY_PRINTK_OMAP5432 >> - default 2 if EARLY_PRINTK_SUN6I >> - default 2 if EARLY_PRINTK_SUN7I >> - default 2 if EARLY_PRINTK_XGENE_MCDIVITT >> - default 2 if EARLY_PRINTK_XGENE_STORM >> default 0 > > Seeing that all know example are setting this to 2, wouldn't it > make sense to change the default to 2 ? It would be a change in behavior and would not fit the purpose of this patch. Also, the EARLY_UART_8250_REG_SHIFT Kconfig help mentions 0 as a default. There might be platforms 8250 based where we don't know the correct reg shift value. Better not to make any assumptions. ~Michal

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