diff options
| -rw-r--r-- | src/fw/paravirt.c | 3 | ||||
| -rw-r--r-- | src/fw/paravirt.h | 3 | ||||
| -rw-r--r-- | src/hw/serialio.c | 16 | ||||
| -rw-r--r-- | src/hw/serialio.h | 1 |
4 files changed, 21 insertions, 2 deletions
diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c index 0770c47b..4fcd8f57 100644 --- a/src/fw/paravirt.c +++ b/src/fw/paravirt.c @@ -75,6 +75,9 @@ static void qemu_detect(void) if (!CONFIG_QEMU_HARDWARE) return; + // Setup QEMU debug output port + qemu_debug_preinit(); + // check northbridge @ 00:00.0 u16 v = pci_config_readw(0, PCI_VENDOR_ID); if (v == 0x0000 || v == 0xffff) diff --git a/src/fw/paravirt.h b/src/fw/paravirt.h index a14d83e1..f7e1d4c5 100644 --- a/src/fw/paravirt.h +++ b/src/fw/paravirt.h @@ -49,6 +49,9 @@ static inline int runningOnKVM(void) { // QEMU_CFG_DMA ID bit #define QEMU_CFG_VERSION_DMA 2 +// QEMU debugcon read value +#define QEMU_DEBUGCON_READBACK 0xe9 + int qemu_cfg_enabled(void); int qemu_cfg_dma_enabled(void); void qemu_preinit(void); diff --git a/src/hw/serialio.c b/src/hw/serialio.c index 319a85c1..31633443 100644 --- a/src/hw/serialio.c +++ b/src/hw/serialio.c @@ -103,11 +103,23 @@ serial_debug_flush(void) u16 DebugOutputPort VARFSEG = 0x402; +void +qemu_debug_preinit(void) +{ + /* Check if the QEMU debug output port is active */ + if (CONFIG_DEBUG_IO && + inb(GET_GLOBAL(DebugOutputPort)) != QEMU_DEBUGCON_READBACK) + DebugOutputPort = 0; +} + // Write a character to the special debugging port. void qemu_debug_putc(char c) { - if (CONFIG_DEBUG_IO && runningOnQEMU()) + if (!CONFIG_DEBUG_IO || !runningOnQEMU()) + return; + u16 port = GET_GLOBAL(DebugOutputPort); + if (port) // Send character to debug port. - outb(c, GET_GLOBAL(DebugOutputPort)); + outb(c, port); } diff --git a/src/hw/serialio.h b/src/hw/serialio.h index 88296fe7..81fed306 100644 --- a/src/hw/serialio.h +++ b/src/hw/serialio.h @@ -24,6 +24,7 @@ void serial_debug_preinit(void); void serial_debug_putc(char c); void serial_debug_flush(void); extern u16 DebugOutputPort; +void qemu_debug_preinit(void); void qemu_debug_putc(char c); #endif // serialio.h |