pxe: automatically add console= to bootargs when not specified in append

From: Dennis Gilmore <[email protected]>

if there is a console variable in the u-boot environment and not one on the append line from syslinux config add what is in the environment to the bootargs.

This is necessary to allow distros to have a single extlinux/extlinux.conf file which will work on multiple boards, even if these boards have different consoles (e.g. ttyS0 vs ttyAMA0).

---
 common/cmd_pxe.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

index ba48692..147d7d1 100644
@@ -606,6 +606,7 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label)
 	char initrd_str[22];
 	char mac_str[29] = "";
 	char ip_str[68] = "";
+	char console[30] = "";
 	char *bootargs;
 	int bootm_argc = 3;
 	int len = 0;

@@ -665,8 +666,14 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label)
 	}
 #endif
 
-	if (label->append)
+	if (label->append) {
 		len += strlen(label->append);
+		/* If no console in append and $console is set, use it */
+		if (!strstr(label->append, "console=") && getenv("console")) {
+			sprintf(console, " console=%s", getenv("console"));
+			len += strlen(console);
+		}
+	}
 
 	if (len) {
 		bootargs = malloc(len + 1);

@@ -675,6 +682,7 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label)
 		bootargs[0] = '\0';
 		if (label->append)
 			strcpy(bootargs, label->append);
+		strcat(bootargs, console);
 		strcat(bootargs, ip_str);
 		strcat(bootargs, mac_str);
 

2.0.3

Hi,

I asked Dennis for its Signed-off-by for this, and instead I got this:

So lets drop this one for now.

Regards,

Hans

Hi,

s/its/his/ sorry.

So if we're not going to do this one we're going to need something else, because without this sunxi is useless, as the last message the user sees is "Starting kernel ..." and then nothing.

Sow how about allowing the use of u-boot environment variables in append, so that extlinux.conf can have:

label Fedora-Minimal-armhfp-rawhide-20140731 (3.16.0-0.rc7.git1.1.fc22.armv7hl)

        kernel /vmlinuz-3.16.0-0.rc7.git1.1.fc22.armv7hl
        append ro root=UUID=a6446dcb-320d-421f-9b71-725b68e5a41b console=$console
        fdtdir /dtb-3.16.0-0.rc7.git1.1.fc22.armv7hl/
        initrd /initramfs-3.16.0-0.rc7.git1.1.fc22.armv7hl.img

And then put 2 entries in extlinux.conf one for booting with the console on the framebuffer, and one for using the serial console ? Even with systems where we have video the user may not have the video hooked up and use the serial console for initial setup.

Alternatively we could use something like this:

console=tty0 console=ttyS0,115200 that will give us boot messages on both video out and ttyS0, dunno what firstboot will do in this case.

Anyways I think we need to separate this discussion in 2 things:

1) Mechanism: u-boot should offer a way for extlinux.conf to find out the right device + baudrate for the serial console. Traditionally this has been done through the console environment variable. If we teach u-boot's extlinux support to interpret $foo variables in the append string, then that mechanism can be used for extlinux.conf booting too, and I think this is the best way to do this.

2) Policy: Once we have 1). the question becomes how to use it in generic ARM distros like Fedora, that discussion is probably best held on the Fedora ARM list and not here.

Regards,

Hans