Re: how to increase commandline size (fwd)

[Jeff Chua]

On Sun, 8 Oct 2006, Marco Gerards wrote:

> > It seems to stop at 256 characters counting the input length
>
> That's weird.  Could you please have a look at loader/i386/pc/linux.c
> to see if it gets the entire line or just a part.  Perhaps this
> limitation is in the protocol used to pass the command line to Linux,
> I don't this protocol.

Marco,

I managed to trace down the limitation to GRUB_LINUX_CL_END_OFFSET.
This limits to 255 characters. I've expanded to 1536 and it seems ok.
I've modified the code to rely on COMMAND_LINE_SIZE defined in the kernel.

ps. Marco had requested that I post this to the mailing list so that you 
all can help verify this is ok.


Here's the patch ...

Thanks for your help,

Jeff.


--- grub2/include/grub/i386/linux.h.org 2006-10-10 01:06:33 +0800
+++ grub2/include/grub/i386/linux.h     2006-10-10 01:07:54 +0800
@@ -17,6 +17,8 @@
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

+#include <asm/param.h>
+
 #ifndef GRUB_LINUX_MACHINE_HEADER
 #define GRUB_LINUX_MACHINE_HEADER      1

@@ -41,8 +43,9 @@
 #define GRUB_LINUX_VID_MODE_ASK                0xFFFD

 #define GRUB_LINUX_CL_OFFSET           0x9000
-#define GRUB_LINUX_CL_END_OFFSET       0x90FF
-#define GRUB_LINUX_SETUP_MOVE_SIZE     0x9100
+#define GRUB_LINUX_CL_END_OFFSET       \
+               (GRUB_LINUX_CL_OFFSET + COMMAND_LINE_SIZE)
+#define GRUB_LINUX_SETUP_MOVE_SIZE     (GRUB_LINUX_CL_END_OFFSET + 1)
 #define GRUB_LINUX_CL_MAGIC            0xA33F

 #define GRUB_LINUX_EFI_SIGNATURE       \
--- grub2/kern/i386/pc/startup.S.org    2006-10-10 01:05:30 +0800
+++ grub2/kern/i386/pc/startup.S        2006-10-10 01:05:45 +0800
@@ -51,6 +51,7 @@
 #include <grub/cpu/linux.h>
 #include <grub/machine/kernel.h>
 #include <grub/machine/multiboot.h>
+#include <asm/param.h>

 #define ABS(x) ((x) - EXT_C(start) + GRUB_BOOT_MACHINE_KERNEL_ADDR + 0x200)

@@ -760,7 +761,7 @@
        /* copy the real mode code */
        movl    EXT_C(grub_linux_tmp_addr), %esi
        movl    %ebx, %edi
-       movl    $GRUB_LINUX_SETUP_MOVE_SIZE, %ecx
+       movl    $(GRUB_LINUX_CL_OFFSET + COMMAND_LINE_SIZE + 1), %ecx
        cld
        rep
        movsb
--- grub2/Makefile.org  2006-10-10 01:05:59 +0800
+++ grub2/Makefile      2006-10-10 01:06:06 +0800
@@ -61,7 +61,7 @@
         -DGRUB_LIBDIR=\"$(pkglibdir)\"
 TARGET_CC = gcc
 TARGET_CFLAGS = -Wall -W -Wshadow -Wpointer-arith -Wmissing-prototypes         
         -Wundef -Wstrict-prototypes -g -Os -falign-jumps=1 -falign-loops=1 
-falign-functions=1
-TARGET_CPPFLAGS =  -I. -Iinclude -I$(srcdir)/include \
+TARGET_CPPFLAGS =  -I/usr/include -I. -Iinclude -I$(srcdir)/include \
        -Wall -W
 TARGET_LDFLAGS =
 OBJCOPY = objcopy