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| author | Robert Morris <[email protected]> | 2019-07-28 07:43:22 -0400 |
|---|---|---|
| committer | Robert Morris <[email protected]> | 2019-07-28 07:43:22 -0400 |
| commit | 1ec50c5848010f607d286228955adb50c05c53ca (patch) | |
| tree | bf448f0074a137e37f696741dd68bc79d621dabb | |
| parent | 2d89a101c45cb73d2800c74ca3ff5c576933e0b7 (diff) | |
| download | xv6-labs-1ec50c5848010f607d286228955adb50c05c53ca.tar.gz xv6-labs-1ec50c5848010f607d286228955adb50c05c53ca.tar.bz2 xv6-labs-1ec50c5848010f607d286228955adb50c05c53ca.zip | |
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| -rw-r--r-- | kernel/uart.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/uart.c b/kernel/uart.c index 852a085..3a5cdc4 100644 --- a/kernel/uart.c +++ b/kernel/uart.c @@ -15,8 +15,9 @@ // address of one of the registers. #define Reg(reg) ((volatile unsigned char *)(UART0 + reg)) -// the registers. some have different meanings for -// read and write. +// the UART control registers. +// some have different meanings for +// read vs write. // http://byterunner.com/16550.html #define RHR 0 // receive holding register (for input bytes) #define THR 0 // transmit holding register (for output bytes) |