This adds the ability to explicitely add an MMIO based serial port
via the 'serial' command. The syntax is:
serial --port=mmio,<hex_address>{.b,.w,.l,.q}
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
# Conflicts:
# grub-core/term/serial.c
---
docs/grub.texi | 26 +++++++++++++--
grub-core/term/serial.c | 71 +++++++++++++++++++++++++++++++++++++++--
2 files changed, 93 insertions(+), 4 deletions(-)
diff --git a/docs/grub.texi b/docs/grub.texi
index fd22a69fa..502ca2ef7 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -4168,8 +4168,24 @@ Commands usable anywhere in the menu and in the
command-line.
@deffn Command serial [@option{--unit=unit}] [@option{--port=port}]
[@option{--speed=speed}] [@option{--word=word}] [@option{--parity=parity}]
[@option{--stop=stop}]
Initialize a serial device. @var{unit} is a number in the range 0-3
specifying which serial port to use; default is 0, which corresponds to
-the port often called COM1. @var{port} is the I/O port where the UART
-is to be found; if specified it takes precedence over @var{unit}.
+the port often called COM1.
+
+@var{port} is the I/O port where the UART is to be found or, if prefixed
+with @samp{mmio,}, the MMIO address of the UART. If specified it takes
+precedence over @var{unit}.
+
+Additionally, an MMIO address can be suffixed with:
+@itemize @bullet
+@item
+@samp{.b} for bytes access (default)
+@item
+@samp{.w} for 16-bit word access
+@item
+@samp{.l} for 32-bit long word access or
+@item
+@samp{.q} for 64-bit long long word access
+@end itemize
+
@var{speed} is the transmission speed; default is 9600. @var{word} and
@var{stop} are the number of data bits and stop bits. Data bits must
be in the range 5-8 and stop bits must be 1 or 2. Default is 8 data
@@ -4185,6 +4201,12 @@ The serial port is not used as a communication channel
unless the
@command{terminal_input} or @command{terminal_output} command is used
(@pxref{terminal_input}, @pxref{terminal_output}).
+Examples:
+@example
+serial --port=3f8 --speed=9600
+serial --port=mmio,fefb0000.l --speed=115200
+@end example
+
See also @ref{Serial terminal}.
@end deffn
diff --git a/grub-core/term/serial.c b/grub-core/term/serial.c
index d49261b48..d161e1d36 100644
--- a/grub-core/term/serial.c
+++ b/grub-core/term/serial.c
@@ -164,6 +164,70 @@ grub_serial_find (const char *name)
if (grub_strcmp (port->name, name) == 0)
break;
}
+ if (!port && grub_strncmp (name, "mmio,", sizeof ("mmio,") - 1) == 0
+ && grub_isxdigit (name [sizeof ("mmio,") - 1]))
+ {
+ const char *p1, *p = &name[sizeof ("mmio,") - 1];
+ grub_addr_t addr = grub_strtoul (p, &p1, 16);
+ unsigned int acc_size = 1;
+ unsigned int nlen = p1 - p;
+
+ /*
+ * If we reach here, we know there's a digit after "mmio,", so
+ * all we need to check is the validity of the character following
+ * the number, which should be a termination, or a dot followed by
+ * an access size
+ */
+ if (p1[0] != '\0' && p1[0] != '.')
+ {
+ grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Incorrect MMIO address
syntax"));
+ return NULL;
+ }
+ if (p1[0] == '.')
+ switch(p1[1])
+ {
+ case 'w':
+ acc_size = 2;
+ break;
+ case 'l':
+ acc_size = 3;
+ break;
+ case 'q':
+ acc_size = 4;
+ break;
+ case 'b':
+ acc_size = 1;
+ break;
+ default:
+ /*
+ * Should we abort for an unknown size ? Let's just default
+ * to 1 byte, it would increase the chance that the user who
+ * did a typo can actually see the console.
+ */
+ grub_error (GRUB_ERR_BAD_ARGUMENT, N_("Incorrect MMIO access
size"));
+ }
+
+ /*
+ * Specifying the access size is optional an
grub_serial_ns8250_add_mmio()
+ * will not add it to the name. So the original loop trying to match an
+ * existing port above might have missed this one. Let's do another
+ * search ignoring the access size part of the string. At this point
+ * nlen contains the length of the name up to the end of the address.
+ */
+ FOR_SERIAL_PORTS (port)
+ if (grub_strncmp (port->name, name, nlen) == 0) {
+ break;
+ }
+
+ name = grub_serial_ns8250_add_mmio (addr, acc_size, NULL);
+ if (name == NULL)
+ return NULL;
+
+ FOR_SERIAL_PORTS (port)
+ if (grub_strcmp (port->name, name) == 0) {
+ break;
+ }
+ }
if (!port && grub_strcmp (name, "auto") == 0)
{
/* Look for an SPCR if any. If not, default to com0 */
@@ -212,8 +276,11 @@ grub_cmd_serial (grub_extcmd_context_t ctxt, int argc,
char **args)
if (state[OPTION_PORT].set)
{
- grub_snprintf (pname, sizeof (pname), "port%lx",
- grub_strtoul (state[1].arg, 0, 0));
+ if (grub_strncmp (state[OPTION_PORT].arg, "mmio,", sizeof ("mmio,") - 1)
== 0)
+ grub_snprintf (pname, sizeof (pname), "%s", state[1].arg);
+ else
+ grub_snprintf (pname, sizeof (pname), "port%lx",
+ grub_strtoul (state[1].arg, 0, 0));
name = pname;
}
--
2.34.1
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