[SeaBIOS] [PATCH v2] serialio: Support for mmap serial ports
Kevin O'Connor
kevin at koconnor.net
Thu Dec 29 01:45:38 CET 2016
On Tue, Dec 20, 2016 at 07:03:58PM +0100, Ricardo Ribalda Delgado wrote:
> Some chipsets have memory mapped serial ports. The protocol is the same
> as an standard uart, but with memory read/write instead of inb/outb.
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda at gmail.com>
> ---
> v2: Fix typos
>
> Suggested by: Kevin O'Connor <kevin at koconnor.net>:
>
> -Only operate in 32bit mode if !MODESEGMENT
>
> src/Kconfig | 3 +++
> src/hw/serialio.c | 32 +++++++++++++++++++++++++-------
> src/serial.c | 2 +-
> 3 files changed, 29 insertions(+), 8 deletions(-)
>
> diff --git a/src/Kconfig b/src/Kconfig
> index e767be1351c3..e53713f2c527 100644
> --- a/src/Kconfig
> +++ b/src/Kconfig
> @@ -532,6 +532,9 @@ menu "Debugging"
> default 0x3f8
> help
> Base port for serial - generally 0x3f8, 0x2f8, 0x3e8, or 0x2e8.
> + On some chipsets the serial port is memory mapped, in those cases
> + provide the 32 bit address. E.g. 0xFEDC6000 for the AMD Kern
> + (a.k.a Hudson UART).
Thanks. I'm a little concerned about overloading the meaning of
CONFIG_DEBUG_SERIAL_PORT to mean either port or memory address. How
about the modified patch below instead?
-Kevin
>From 9968b2ef2bbfaf7271cd2d27302161e141200738 Mon Sep 17 00:00:00 2001
From: Ricardo Ribalda Delgado <ricardo.ribalda at gmail.com>
Date: Tue, 20 Dec 2016 19:03:58 +0100
Subject: [PATCH] serialio: Support for mmap serial ports
Some chipsets have memory mapped serial ports. The protocol is the same
as an standard uart, but with memory read/write instead of inb/outb.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda at gmail.com>
Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
---
src/Kconfig | 13 +++++++++++++
src/hw/serialio.c | 44 ++++++++++++++++++++++++++++++++++----------
2 files changed, 47 insertions(+), 10 deletions(-)
diff --git a/src/Kconfig b/src/Kconfig
index e767be1..457d082 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -532,6 +532,19 @@ menu "Debugging"
default 0x3f8
help
Base port for serial - generally 0x3f8, 0x2f8, 0x3e8, or 0x2e8.
+ config DEBUG_SERIAL_MMIO
+ depends on DEBUG_LEVEL != 0 && !DEBUG_SERIAL
+ bool "Serial port debugging via memory mapped IO"
+ default n
+ help
+ Send debugging information to serial port mapped in memory.
+ config DEBUG_SERIAL_MEM_ADDRESS
+ depends on DEBUG_SERIAL_MMIO
+ hex "Serial port memory mapped IO address"
+ help
+ On some chipsets the serial port is memory mapped, in those cases
+ provide the 32 bit address. E.g. 0xFEDC6000 for the AMD Kern
+ (a.k.a Hudson UART).
config DEBUG_IO
depends on QEMU_HARDWARE && DEBUG_LEVEL != 0
diff --git a/src/hw/serialio.c b/src/hw/serialio.c
index 6486fc0..319a85c 100644
--- a/src/hw/serialio.c
+++ b/src/hw/serialio.c
@@ -17,20 +17,44 @@
#define DEBUG_TIMEOUT 100000
+// Write to a serial port register
+static void
+serial_debug_write(u8 offset, u8 val)
+{
+ if (CONFIG_DEBUG_SERIAL) {
+ outb(val, CONFIG_DEBUG_SERIAL_PORT + offset);
+ } else if (CONFIG_DEBUG_SERIAL_MMIO) {
+ ASSERT32FLAT();
+ writeb((void*)CONFIG_DEBUG_SERIAL_MEM_ADDRESS + 4*offset, val);
+ }
+}
+
+// Read from a serial port register
+static u8
+serial_debug_read(u8 offset)
+{
+ if (CONFIG_DEBUG_SERIAL)
+ return inb(CONFIG_DEBUG_SERIAL_PORT + offset);
+ if (CONFIG_DEBUG_SERIAL_MMIO) {
+ ASSERT32FLAT();
+ return readb((void*)CONFIG_DEBUG_SERIAL_MEM_ADDRESS + 4*offset);
+ }
+}
+
// Setup the debug serial port for output.
void
serial_debug_preinit(void)
{
- if (!CONFIG_DEBUG_SERIAL)
+ if (!CONFIG_DEBUG_SERIAL && (!CONFIG_DEBUG_SERIAL_MMIO || MODESEGMENT))
return;
// setup for serial logging: 8N1
u8 oldparam, newparam = 0x03;
- oldparam = inb(CONFIG_DEBUG_SERIAL_PORT+SEROFF_LCR);
- outb(newparam, CONFIG_DEBUG_SERIAL_PORT+SEROFF_LCR);
+ oldparam = serial_debug_read(SEROFF_LCR);
+ serial_debug_write(SEROFF_LCR, newparam);
// Disable irqs
u8 oldier, newier = 0;
- oldier = inb(CONFIG_DEBUG_SERIAL_PORT+SEROFF_IER);
- outb(newier, CONFIG_DEBUG_SERIAL_PORT+SEROFF_IER);
+ oldier = serial_debug_read(SEROFF_IER);
+ serial_debug_write(SEROFF_IER, newier);
if (oldparam != newparam || oldier != newier)
dprintf(1, "Changing serial settings was %x/%x now %x/%x\n"
@@ -41,14 +65,14 @@ serial_debug_preinit(void)
static void
serial_debug(char c)
{
- if (!CONFIG_DEBUG_SERIAL)
+ if (!CONFIG_DEBUG_SERIAL && (!CONFIG_DEBUG_SERIAL_MMIO || MODESEGMENT))
return;
int timeout = DEBUG_TIMEOUT;
- while ((inb(CONFIG_DEBUG_SERIAL_PORT+SEROFF_LSR) & 0x20) != 0x20)
+ while ((serial_debug_read(SEROFF_LSR) & 0x20) != 0x20)
if (!timeout--)
// Ran out of time.
return;
- outb(c, CONFIG_DEBUG_SERIAL_PORT+SEROFF_DATA);
+ serial_debug_write(SEROFF_DATA, c);
}
void
@@ -63,10 +87,10 @@ serial_debug_putc(char c)
void
serial_debug_flush(void)
{
- if (!CONFIG_DEBUG_SERIAL)
+ if (!CONFIG_DEBUG_SERIAL && (!CONFIG_DEBUG_SERIAL_MMIO || MODESEGMENT))
return;
int timeout = DEBUG_TIMEOUT;
- while ((inb(CONFIG_DEBUG_SERIAL_PORT+SEROFF_LSR) & 0x60) != 0x60)
+ while ((serial_debug_read(SEROFF_LSR) & 0x60) != 0x60)
if (!timeout--)
// Ran out of time.
return;
--
2.5.5
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