x86: Make debug UART port configurable via system config

We already allow to enable a VGA console via the system config, so let's
make the UART port configurable this way as well: phys_start will hold
the port, and flags must not have JAILHOUSE_MEM_IO set, in order to
differentiate us from the memory-mapped VGA console. And by leaving
phys_start at 0, we can even turn off the console now.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

diff --git a/hypervisor/arch/x86/dbg-write.c b/hypervisor/arch/x86/dbg-write.c
index cdb6b85f8d23058410f77e295901814d5b38ece5..df6f45932405c2340328f90559e739d217c16c5c 100644 (file)
--- a/hypervisor/arch/x86/dbg-write.c
+++ b/hypervisor/arch/x86/dbg-write.c
@@ -12,35 +12,39 @@
  * the COPYING file in the top-level directory.
  */
 
+#include <jailhouse/control.h>
 #include <jailhouse/entry.h>
 #include <jailhouse/printk.h>
 #include <jailhouse/processor.h>
 #include <asm/io.h>
 
-#ifdef CONFIG_UART_OXPCIE952
-#define UART_BASE              0xe010
-#else
-#define UART_BASE              0x3f8
-#endif
-#define  UART_TX               0x0
-#define  UART_DLL              0x0
-#define  UART_DLM              0x1
-#define  UART_LCR              0x3
-#define  UART_LCR_8N1          0x03
-#define  UART_LCR_DLAB         0x80
-#define  UART_LSR              0x5
-#define  UART_LSR_THRE         0x20
+#define UART_TX                        0x0
+#define UART_DLL               0x0
+#define UART_DLM               0x1
+#define UART_LCR               0x3
+#define UART_LCR_8N1           0x03
+#define UART_LCR_DLAB          0x80
+#define UART_LSR               0x5
+#define UART_LSR_THRE          0x20
+
+static u16 uart_base;
 
 static void uart_init(void)
 {
-       outb(UART_LCR_DLAB, UART_BASE + UART_LCR);
+       if (system_config->debug_console.phys_start == 0 ||
+           system_config->debug_console.flags & JAILHOUSE_MEM_IO)
+               return;
+
+       uart_base = system_config->debug_console.phys_start;
+
+       outb(UART_LCR_DLAB, uart_base + UART_LCR);
 #ifdef CONFIG_UART_OXPCIE952
-       outb(0x22, UART_BASE + UART_DLL);
+       outb(0x22, uart_base + UART_DLL);
 #else
-       outb(1, UART_BASE + UART_DLL);
+       outb(1, uart_base + UART_DLL);
 #endif
-       outb(0, UART_BASE + UART_DLM);
-       outb(UART_LCR_8N1, UART_BASE + UART_LCR);
+       outb(0, uart_base + UART_DLM);
+       outb(UART_LCR_8N1, uart_base + UART_LCR);
 }
 
 static void uart_write(const char *msg)
@@ -54,11 +58,11 @@ static void uart_write(const char *msg)
                        c = *msg++;
                if (!c)
                        break;
-               while (!(inb(UART_BASE + UART_LSR) & UART_LSR_THRE))
+               while (!(inb(uart_base + UART_LSR) & UART_LSR_THRE))
                        cpu_relax();
                if (panic_in_progress && panic_cpu != phys_processor_id())
                        break;
-               outb(c, UART_BASE + UART_TX);
+               outb(c, uart_base + UART_TX);
        }
 }
 
@@ -134,14 +138,13 @@ static void vga_write(const char *msg)
 void arch_dbg_write_init(void)
 {
        vga_init();
-       if (!vga_mem)
-               uart_init();
+       uart_init();
 }
 
 void arch_dbg_write(const char *msg)
 {
        if (vga_mem)
                vga_write(msg);
-       else
+       else if (uart_base)
                uart_write(msg);
 }