Improve warnings when failing to read kernel via TFTP

It seems the firmware boot loader code isn't able to load images
via TFTP if those are bigger than 30MB. Instead it runs into timeouts
and reports errors back to the palo bootloader.

This patch detects such situations and prints a useful warning before
rebooting.

Signed-off-by: Helge Deller <deller@gmx.de>

1 files changed, 18 insertions, 6 deletions

diff --git a/ipl/pdc_bootio.c b/ipl/pdc_bootio.c
index 496f117..52fe1de 100644
--- a/ipl/pdc_bootio.c
+++ b/ipl/pdc_bootio.c
@@ -62,7 +62,12 @@ static int pdc_bootdev_read(int fd,
 	    if ((count = pdc_iodc_bootin(devaddr, dest, nseek)) < 0)
 	    {
 	        die("pdc_iodc_bootin() died during seekread\r\n");
+		devaddr += nseek;
+abort_with_warning:
+		if (devaddr > 30*1024*1024)	/* 30MB */
+			puts("If you boot via tftp you probably reached the 32MB limit.\n");
 		pdc_do_reset();
+		return -1;
 	    }
 	    devaddr += count;
 	}
@@ -72,11 +77,17 @@ static int pdc_bootdev_read(int fd,
     {
 	int count;
 
-	if (Debug) printf("pdc_iodc_bootin(dev:0x%x, buf:0x%p, count:%u)\r\n",
-		devaddr, dest+nbytes, n - nbytes);
-	count = pdc_iodc_bootin(devaddr, dest + nbytes, n - nbytes);
+	/* how many bytes should be read? */
+	count = n - nbytes;
 
-	if (Debug)
+	if (Debug) printf("pdc_iodc_bootin(dev:0x%x, buf:0x%p, count:%u) = ",
+		devaddr, dest+nbytes, count);
+
+	count = pdc_iodc_bootin(devaddr, dest + nbytes, count);
+
+	if (Debug) printf("%d\r\n", count);
+
+	if (0 && Debug)
 	{
 	    printf("%d@0x%x ", count, devaddr);
 	    {
@@ -106,8 +117,9 @@ static int pdc_bootdev_read(int fd,
 	    /* essentially be lost right now */
 	    printf("\nERROR: Read from boot device failed (status = %d).\n",
 		count);
-	    nbytes = -1;
-	    break;
+
+	    devaddr += (n - nbytes);
+	    goto abort_with_warning;
 	}
     }