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authorMatt Harvey <[email protected]>2020-09-14 14:49:57 -0700
committerFrans Kaashoek <[email protected]>2020-10-03 16:35:47 -0400
commitb9359c353318ba70596b55ec57f8d9f6c43c2758 (patch)
tree5ef3b9930268af82827696ec2e88ca10909ecc24
parentb96547403df0e07865bc2269215cfeb0260b893d (diff)
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Corrects order of UART RX/TX interrupt enable bits
(per http://byterunner.com/16550.html and manually tested in qemu bare metal echo)
-rw-r--r--kernel/uart.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/uart.c b/kernel/uart.c
index ce89615..d586ea4 100644
--- a/kernel/uart.c
+++ b/kernel/uart.c
@@ -22,8 +22,8 @@
#define RHR 0 // receive holding register (for input bytes)
#define THR 0 // transmit holding register (for output bytes)
#define IER 1 // interrupt enable register
-#define IER_TX_ENABLE (1<<0)
-#define IER_RX_ENABLE (1<<1)
+#define IER_RX_ENABLE (1<<0)
+#define IER_TX_ENABLE (1<<1)
#define FCR 2 // FIFO control register
#define FCR_FIFO_ENABLE (1<<0)
#define FCR_FIFO_CLEAR (3<<1) // clear the content of the two FIFOs