Hi Bin,
On Mon, 2018-09-17 at 13:02 +0800, Bin Meng wrote:
Hi Lukas,
On Mon, Sep 17, 2018 at 5:09 AM Auer, Lukas lukas.auer@aisec.fraunhofer.de wrote:
Hi Bin,
On Mon, 2018-09-10 at 21:54 -0700, Bin Meng wrote:
We don't have a reset method on any RISC-V board yet. Instead of adding the same 'unsupported' message for each CPU variant it might make more sense to add a generic do_reset function for all CPU variants to lib/, similar to the one for ARM (arch/arm/lib/reset.c).
Suggested-by: Lukas Auer lukas.auer@aisec.fraunhofer.de Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2:
- new patch to move do_reset() to a common place
arch/riscv/cpu/ax25/cpu.c | 9 --------- arch/riscv/cpu/qemu/cpu.c | 8 -------- arch/riscv/lib/Makefile | 1 + arch/riscv/lib/reset.c | 14 ++++++++++++++ 4 files changed, 15 insertions(+), 17 deletions(-) create mode 100644 arch/riscv/lib/reset.c
diff --git a/arch/riscv/cpu/ax25/cpu.c b/arch/riscv/cpu/ax25/cpu.c index ab05b57..fddcc15 100644 --- a/arch/riscv/cpu/ax25/cpu.c +++ b/arch/riscv/cpu/ax25/cpu.c @@ -6,9 +6,6 @@
/* CPU specific code */ #include <common.h> -#include <command.h> -#include <watchdog.h> -#include <asm/cache.h>
/*
- cleanup_before_linux() is called just before we call linux
@@ -24,9 +21,3 @@ int cleanup_before_linux(void)
return 0;}
-int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) -{
disable_interrupts();panic("ax25-ae350 wdt not support yet.\n");-} diff --git a/arch/riscv/cpu/qemu/cpu.c b/arch/riscv/cpu/qemu/cpu.c index a064639..6c7a327 100644 --- a/arch/riscv/cpu/qemu/cpu.c +++ b/arch/riscv/cpu/qemu/cpu.c @@ -4,7 +4,6 @@ */
#include <common.h> -#include <command.h>
/*
- cleanup_before_linux() is called just before we call linux
@@ -20,10 +19,3 @@ int cleanup_before_linux(void)
return 0;}
-int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) -{
printf("reset unsupported yet\n");return 0;-} diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index cc562f9..b58db89 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_CMD_BOOTM) += bootm.o obj-$(CONFIG_CMD_GO) += boot.o obj-y += cache.o obj-y += interrupts.o +obj-y += reset.o obj-y += setjmp.o
# For building EFI apps diff --git a/arch/riscv/lib/reset.c b/arch/riscv/lib/reset.c new file mode 100644 index 0000000..5d9b99c --- /dev/null +++ b/arch/riscv/lib/reset.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Copyright (C) 2018, Bin Meng bmeng.cn@gmail.com
- */
+#include <common.h> +#include <command.h>
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{
printf("reset unsupported yet\n");return 0;+}
Thanks for adding this patch! I see one possible problem with it. The way you implemented it, arch / board code can't overwrite the function to add a reset method. How about something like this?
Thanks for your review and comments. I believe current implementation in this patch is an interim approach, for now to save some duplicates. The problem you mentioned can be resolved by implementing a SYSRESET uclass driver for that CPU/board in the future.
That's true, still, two minor things I would consider to change.
- A simple wording changes to make it clear that the reset is not only not available, but u-boot actually tried to reset the system. So something like this: "Resetting... reset not supported yet".
- I don't know how much of an issue it is that u-boot keeps running after a reset. I would tend to use panic() together with PANIC_HANG, to make sure u-boot halts. You know u-boot better than me, what do you think?
Thanks, Lukas
Reviewed-by: Lukas Auer lukas.auer@aisec.fraunhofer.de
- do_reset() only prints "resetting..." and then calls cpu_reset()
- reset.c includes a weak cpu_reset() function that prints the
warning you currently have in this patch (by the way, it should say "reset not supported yet"). It might also make sense to print the warning with the panic() function and define PANIC_HANG, so that u-boot is halted on resets. cpu_reset() can then be defined by boards that have an actual reset method.
Regards, Bin