x86, setup: Make the setup code also accept console=uart8250

Make the boot code also accept the console=uart8250,io,0x2f8,115200n
form of early console.

Also add back simple_guess_base(), otherwise those simple_strtoull(,,0)
are not going to work.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C3CCE05.4090505@kernel.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index aba29df..3cbc405 100644 (file)
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -68,10 +68,32 @@ unsigned int atou(const char *s)
 /* Works only for digits and letters, but small and fast */
 #define TOLOWER(x) ((x) | 0x20)
 
+static unsigned int simple_guess_base(const char *cp)
+{
+       if (cp[0] == '0') {
+               if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
+                       return 16;
+               else
+                       return 8;
+       } else {
+               return 10;
+       }
+}
+
+/**
+ * simple_strtoull - convert a string to an unsigned long long
+ * @cp: The start of the string
+ * @endp: A pointer to the end of the parsed string will be placed here
+ * @base: The number base to use
+ */
+
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 {
        unsigned long long result = 0;
 
+       if (!base)
+               base = simple_guess_base(cp);
+
        if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
                cp += 2;
 

diff --git a/arch/x86/boot/tty.c b/arch/x86/boot/tty.c
index f3ceee2..f6d52e6 100644 (file)
--- a/arch/x86/boot/tty.c
+++ b/arch/x86/boot/tty.c
@@ -170,7 +170,7 @@ static void early_serial_init(int baud)
        outb(c & ~DLAB, early_serial_base + LCR);
 }
 
-void console_init(void)
+static int parse_earlyprintk(void)
 {
        int baud = DEFAULT_BAUD;
        char arg[32];
@@ -208,6 +208,63 @@ void console_init(void)
                        baud = DEFAULT_BAUD;
        }
 
+       return baud;
+}
+
+#define BASE_BAUD (1843200/16)
+static unsigned int probe_baud(int port)
+{
+       unsigned char lcr, dll, dlh;
+       unsigned int quot;
+
+       lcr = inb(port + LCR);
+       outb(lcr | DLAB, port + LCR);
+       dll = inb(port + DLL);
+       dlh = inb(port + DLH);
+       outb(lcr, port + LCR);
+       quot = (dlh << 8) | dll;
+
+       return BASE_BAUD / quot;
+}
+
+static int parse_console_uart8250(void)
+{
+       char optstr[64], *options;
+       int baud = DEFAULT_BAUD;
+
+       /*
+        * console=uart8250,io,0x3f8,115200n8
+        * need to make sure it is last one console !
+        */
+       if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
+               return baud;
+
+       options = optstr;
+
+       if (!strncmp(options, "uart8250,io,", 12))
+               early_serial_base = simple_strtoull(options + 12, &options, 0);
+       else if (!strncmp(options, "uart,io,", 8))
+               early_serial_base = simple_strtoull(options + 8, &options, 0);
+       else
+               return baud;
+
+       if (options && (options[0] == ','))
+               baud = simple_strtoull(options + 1, &options, 0);
+       else
+               baud = probe_baud(early_serial_base);
+
+       return baud;
+}
+
+void console_init(void)
+{
+       int baud;
+
+       baud = parse_earlyprintk();
+
+       if (!early_serial_base)
+               baud = parse_console_uart8250();
+
        if (early_serial_base != 0)
                early_serial_init(baud);
 }