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* [PATCH 0/3] RISC-V SBI earlycon
@ 2018-12-04 13:55 Anup Patel
  2018-12-04 13:55 ` [PATCH 1/3] tty/serial: Add RISC-V SBI earlycon support Anup Patel
                   ` (4 more replies)
  0 siblings, 5 replies; 20+ messages in thread
From: Anup Patel @ 2018-12-04 13:55 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Jiri Slaby, Palmer Dabbelt, Albert Ou
  Cc: Rob Herring, Anup Patel, linux-kernel, Christoph Hellwig,
	Atish Patra, linux-serial, linux-riscv

This patchset adds RISC-V SBI earlycon and removes RISC-V EARLY_PRINTK.

We should use earlycon over existing EARLY_PRINTK for SBI console because:
1. It's a more generic way of implementing early console for debugging
2. Current RISC-V EARLY_PRINTK is a compile-time option whereas earlycon
   is enabled at run-time via kernel parameters.
3. To use earlycon with SBI, we have to pass "earlycon=sbi" in kernel
   parameters. If earlycon kernel parameter is not provided then kernel
   boots much faster which is very useful in real-world RISC-V deployments.

The patchset is tested on QEMU virt machine. It is based on Linux-4.20-rc5
and can be found at riscv_earlycon_v1 branch of:
https://github.com/avpatel/linux.git

Anup Patel (3):
  tty/serial: Add RISC-V SBI earlycon support
  RISC-V: defconfig: Enable RISC-V SBI earlycon support
  RISC-V: Remove EARLY_PRINTK support

 arch/riscv/Kconfig.debug                |  2 --
 arch/riscv/configs/defconfig            |  1 +
 arch/riscv/kernel/setup.c               | 28 -------------------------
 drivers/tty/serial/Kconfig              | 12 +++++++++++
 drivers/tty/serial/Makefile             |  1 +
 drivers/tty/serial/earlycon-riscv-sbi.c | 28 +++++++++++++++++++++++++
 6 files changed, 42 insertions(+), 30 deletions(-)
 create mode 100644 drivers/tty/serial/earlycon-riscv-sbi.c

-- 
2.17.1


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^ permalink raw reply	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2019-03-25 16:23 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-12-04 13:55 [PATCH 0/3] RISC-V SBI earlycon Anup Patel
2018-12-04 13:55 ` [PATCH 1/3] tty/serial: Add RISC-V SBI earlycon support Anup Patel
2018-12-05  9:58   ` Greg Kroah-Hartman
2018-12-07 18:45     ` Palmer Dabbelt
2018-12-07 18:30   ` Palmer Dabbelt
2019-01-10 14:07   ` [PATCH] tty/serial: emit CR before NL in RISC-V SBL console Andreas Schwab
2019-01-10 15:16     ` Anup Patel
2019-01-10 15:26       ` Andreas Schwab
2019-01-10 16:17         ` Anup Patel
2019-01-10 17:11           ` [PATCH] tty/serial: use uart_console_write in the RISC-V SBL early console Andreas Schwab
2019-01-11 11:13             ` Anup Patel
2019-01-23 23:58               ` Palmer Dabbelt
2019-01-15 13:59             ` Christoph Hellwig
2019-01-10 20:54           ` [PATCH] tty/serial: emit CR before NL in RISC-V SBL console Palmer Dabbelt
2018-12-04 13:55 ` [PATCH 2/3] RISC-V: defconfig: Enable RISC-V SBI earlycon support Anup Patel
2018-12-07 18:30   ` Palmer Dabbelt
2018-12-04 13:55 ` [PATCH 3/3] RISC-V: Remove EARLY_PRINTK support Anup Patel
2018-12-07 18:30   ` Palmer Dabbelt
2018-12-07 18:30 ` [PATCH 0/3] RISC-V SBI earlycon Palmer Dabbelt
2019-03-25 16:23 ` Andreas Schwab

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