[PATCH] riscv: timer: Add support for an early timer

[Rick Chen]

Hi Pragnesh


> Hi Rick,
>
> [...]
> >>
> >>Following are the configurations, steps and debug logs:
> >>
> >>+++ b/configs/ae350_rv64_defconfig
> >>q+CONFIG_TRACE=y
> >>+CONFIG_TRACE_BUFFER_SIZE=0x01000000
> >>+CONFIG_TRACE_CALL_DEPTH_LIMIT=15
> >>+CONFIG_CMD_TRACE=y
> >>+CONFIG_TIMER_EARLY=y
> >>
> >>+++ b/configs/ae350_rv64_spl_defconfig
> >>+CONFIG_TRACE=y
> >>+CONFIG_TRACE_BUFFER_SIZE=0x01000000
> >>+CONFIG_TRACE_CALL_DEPTH_LIMIT=15
> >>+CONFIG_CMD_TRACE=y
> >>+CONFIG_TIMER_EARLY=y
> >>
> >>//////////////////////////////////////////////// case 1
> >>///////////////////////////////////////////////////
> >>ae350_rv64_defconfig with FTRACE=1, kernel booting is ok
> >>//////////////////////////////////////////////// case 1
> >>///////////////////////////////////////////////////
> >>make FTRACE=1 ae350_rv64_defconfig
> >>make FTRACE=1
> >>///////////////////////////////////////////////////////////////////////
> [...]
> >>//////////////////////////////////////////////// case 2
> >>///////////////////////////////////////////////////
> >>ae350_rv64_spl_defconfig with FTRACE=1, kernel booting fail
> >>//////////////////////////////////////////////// case 2
> >>///////////////////////////////////////////////////
> >>make FTRACE=1 ae350_rv64_spl_defconfig
> >>make FTRACE=1
> >>///////////////////////////////////////////////////////////////////////
> >>///////////////
> >>/////////////////////////
> [...]
> >>(hang here)
> >
> >Thanks for the logs.
> >
> >From logs, I can't find where it got stuck. Can you please use gdb to see where it
> >got stuck ?
> >
> >Meanwhile I will give it a try on HiFive Unleashed board.
>
> On HiFive Unleashed it works fine with tracing.
>
> U-Boot 2021.01-rc2-00049-gb2a38d1d0f (Dec 01 2020 - 15:04:41 +0530)
> CPU:   rv64imafdc
> Model: SiFive HiFive Unleashed A00
> DRAM:  8 GiB
> trace: enabled
> MMC:   spi at 10050000:mmc at 0: 0
> Loading Environment from SPIFlash... SF: Detected is25wp256 with page size 256 Bytes, erase size 4 KiB, total 32 MiB
> *** Warning - bad CRC, using default environment
> In:    serial at 10010000
> Out:   serial at 10010000
> Err:   serial at 10010000
> Net:   eth0: ethernet at 10090000
> Hit any key to stop autoboot:  0
> =>
> => trace stats
>         178,750 function sites
>      25,359,991 function calls
>               1 untracked function calls
>       1,278,927 traced function calls (24358307 dropped due to overflow)
>              19 maximum observed call depth
>              15 call depth limit
>      25,238,922 calls not traced due to depth
> => fatload mmc 0:3 0x86000000 hifive-unleashed-a00.dtb
> 7199 bytes read in 27 ms (259.8 KiB/s)
> => fatload mmc 0:3 0x84000000 uImage
> 21421212 bytes read in 19496 ms (1 MiB/s)
> => bootm 0x84000000 - 0x86000000
> ## Booting kernel from Legacy Image at 84000000 ...
>    Image Name:   Linux
>    Image Type:   RISC-V Linux Kernel Image (uncompressed)
>    Data Size:    21421148 Bytes = 20.4 MiB
>    Load Address: 80200000
>    Entry Point:  80200000
>    Verifying Checksum ... OK
> ## Flattened Device Tree blob at 86000000
>    Booting using the fdt blob at 0x86000000
>    Loading Kernel Image
>    Using Device Tree in place at 0000000086000000, end 0000000086004c1e
> Starting kernel ...(fake run for tracing)
> Starting kernel ...
> [    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
> [    0.000000] Linux version 5.8.0-rc3-16077-g9ebcfadb0610-dirty (pragneshp at sachinj2-OptiPlex-7010) (riscv64-unknown-linux-gnu-gcc (crosstool-NG 1.24.0.37-3f461da) 9.2.0, GNU ld (crosstool-NG 1.24.0.37-3f461da) 2.32) #34 SMP Tue Jul 21 15:56:29 IST 2020
> [    0.000000] initrd not found or empty - disabling initrd
> [    0.000000] Zone ranges:
> [    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000ffffffff]
> [    0.000000]   Normal   [mem 0x0000000100000000-0x000000027fffffff]
> [    0.000000] Movable zone start for each node
> [    0.000000] Early memory node ranges
> [    0.000000]   node   0: [mem 0x0000000080200000-0x000000027fffffff]
> [    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x000000027fffffff]
> ....
> Welcome to Buildroot
> buildroot login: root
> Password:
>

Please check about the CI failure item Job #95.56
https://travis-ci.org/github/rickchen36/u-boot-riscv/jobs/748298543

Thanks,
Rick