[PATCH v3 0/3] Add RISC-V 32 NOMMU support

[Randy Dunlap]

On 3/7/23 18:33, Randy Dunlap wrote:
> 
> 
> On 3/7/23 18:30, Jesse Taube wrote:
>>
>>
>> On 3/7/23 21:16, Randy Dunlap wrote:
>>> Hi--
>>>
>>> On 3/7/23 17:26, Jesse Taube wrote:
>>>>
>>>>
>>>> On 2/28/23 23:42, Damien Le Moal wrote:
>>>>> On 3/1/23 13:07, Randy Dunlap wrote:
>>>>>> Hi--
>>>>>>
>>>>>> On 2/28/23 16:26, Jesse Taube wrote:
>>>>>>> This patch-set aims to add NOMMU support to RV32.
>>>>>>> Many people want to build simple emulators or HDL
>>>>>>> models of RISC-V this patch makes it possible to
>>>>>>> run linux on them.
>>>>>>>
>>>>>>> Yimin Gu is the original author of this set.
>>>>>>> Submitted here:
>>>>>>> https://lists.buildroot.org/pipermail/buildroot/2022-November/656134.html
>>>>>>>
>>>>>>> Though Jesse T rewrote the Dconf.
>>>>>>
>>>>>> Dconf?
>>>>>>
>>>>>>>
>>>>>>> The new set:
>>>>>>> https://lists.buildroot.org/pipermail/buildroot/2022-December/658258.html
>>>>>>> ---
>>>>>>> V1->V2:
>>>>>>>    - Add Conor's clock patch for implicit div64
>>>>>>>    - Fix typo in commit title 3/3
>>>>>>>    - Fix typo in commit description 2/3
>>>>>>> V2->V3
>>>>>>>    - Change from defconfig file to a PHONY config
>>>>>>> ---
>>>>>>
>>>>>> Is this 'rv32_nommu_virt_defconfig' target the only build target
>>>>>> that is supported?
>>>>>>
>>>>>> I ask because I applied the 3 patches and did 25 randconfig builds.
>>>>>> 5 of them failed the same way:
>>>>>>
>>>>>> riscv32-linux-ld: drivers/soc/canaan/k210-sysctl.o: in function `k210_soc_early_init':
>>>>>> k210-sysctl.c:(.init.text+0x78): undefined reference to `k210_clk_early_init'
>>>> I can not recreate this error.
>>>> can you send me the .config you used.
>>>>
>>>> Thanks,
>>>> Jesse Taube
>>>
>>> Sure, it's attached.
>>
>> Hmmm, it links fine for me.
>>
>> objdump -x vmlinux | grep k210_clk_early_init
>> 81e40124 g     F .init.text     00000088 k210_clk_early_init
>>
>> gcc version 11.3.0 (Buildroot 2022.11-361-g1be0d438f7)
>> GNU assembler version 2.38 (riscv32-buildroot-linux-uclibc)
>> GNU ld (GNU Binutils) 2.38
>>
>> what gcc version are you using?
> 
> 
> gcc (SUSE Linux) 12.2.1 20230124 [revision 193f7e62815b4089dfaed4c2bd34fd4f10209e27]
> from opensuse Tumbleweed.
> 
> I'll try it on a current tree...

OK, I don't know how it happened. I cannot reproduce it now.
The failing .config files has CONFIG_MMU is not set (for RV32I), which
appears to be impossible.

Sorry to bother you.

Thanks.

>>>
>>>>> Arg. Forgot about that. k210 is rv64 only and while the clk driver could still
>>>>> compile test with rv32 (or any arch), that driver provides the
>>>>> k210_clk_early_init() function which is called very early in the boot process
>>>>> from k210_soc_early_init(), which is an SOC_EARLY_INIT_DECLARE() call. The
>>>>> problem may be there. Probably should be disabled for rv32 if no SoC need that
>>>>> sort of early init call.
>>>>>
>>>>>>
>>>>>> because
>>>>>> # CONFIG_COMMON_CLK_K210 is not set
>>>>>>
>>>>>>
>>>>>> Maybe SOC_CANAAN needs some more selects for required code?
>>>>>>
>>>>>>> Conor Dooley (1):
>>>>>>>     clk: k210: remove an implicit 64-bit division
>>>>>>>
>>>>>>> Jesse Taube (1):
>>>>>>>     riscv: configs: Add nommu PHONY defconfig for RV32
>>>>>>>
>>>>>>> Yimin Gu (1):
>>>>>>>     riscv: Kconfig: Allow RV32 to build with no MMU
>>>>>>>
>>>>>>>    arch/riscv/Kconfig     | 5 ++---
>>>>>>>    arch/riscv/Makefile    | 4 ++++
>>>>>>>    drivers/clk/clk-k210.c | 2 +-
>>>>>>>    3 files changed, 7 insertions(+), 4 deletions(-)
>>>>>>>
>>>>>>
>>>>>
>>>
> 

-- 
~Randy