diff options
| author | Stafford Horne <shorne@gmail.com> | 2022-05-15 07:33:14 +0300 |
|---|---|---|
| committer | Stafford Horne <shorne@gmail.com> | 2022-05-23 11:15:49 +0300 |
| commit | 29bbb2a90fcdd46d9f12746deac4718082df325a (patch) | |
| tree | 31e3282531fa595c92ce910b2db3f918b355f490 | |
| parent | e449759c246e1594307760f7203debf6038a42ea (diff) | |
| download | linux-29bbb2a90fcdd46d9f12746deac4718082df325a.tar.xz | |
openrisc: Add support for liteuart emergency printing
This patch adds support for sending emergency print output, such as
unhandled exception details, to a liteuart serial device. This is the
default device available on litex platforms.
If a developer want to use this they should update UART_BASE_ADD
to the address of liteuart.
Signed-off-by: Stafford Horne <shorne@gmail.com>
| -rw-r--r-- | arch/openrisc/kernel/head.S | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S index 7bfa6e4b60c5..21db50563f97 100644 --- a/arch/openrisc/kernel/head.S +++ b/arch/openrisc/kernel/head.S @@ -1555,7 +1555,18 @@ ENTRY(_emergency_putc) l.movhi r4,hi(UART_BASE_ADD) l.ori r4,r4,lo(UART_BASE_ADD) -#if defined(CONFIG_SERIAL_8250) +#if defined(CONFIG_SERIAL_LITEUART) + /* Check OFF_TXFULL status */ +1: l.lwz r5,4(r4) + l.andi r5,r5,0xff + l.sfnei r5,0 + l.bf 1b + l.nop + + /* Write character */ + l.andi r7,r7,0xff + l.sw 0(r4),r7 +#elif defined(CONFIG_SERIAL_8250) /* Check UART LSR THRE (hold) bit */ l.addi r6,r0,0x20 1: l.lbz r5,5(r4) |