etherboot-developers

[Etherboot-developers] booting non linux images

[Anuradha R. <anu...@gn...>]

Hello,

We have setup dhcp/tftp on debian 2.2 and things are working fine with a
linux kernel tagged with mknbi-linux.

We need to run a progarm called memtest86 which runs stand alone, i.e., it
is completely contained in a bootable image. Its booting procedure is
based on _very_ old linux kernels. And many signatures and magic numbers
seem to be minix compliant. Therefore mknbi-linux doesn't work.

I read in the tagged image spec that any image with bytes at offsets 510
and 511 set to 55 and aa (may be the other way) is also valid, and this
image _does_ contain those values. But etherboot doesn't detect it. I am
extensively going through source code to get things fixed. I found that
the file main.c does not check for these values. However the files in
contrib/baremetal/main.c (line 461) _does_ this with wrong pointer
manipulation.

Also I understand a tagged image with a second magic number should be
loaded at 0x10000 (not the boot sector which comes to 0x7c00) and not to
0x100000. Does etherboot handle this?

Anuradha

Re: [Etherboot-developers] booting non linux images

[<ebi...@ln...>]

Anuradha Ratnaweera <anu...@gn...> writes:

> Hello,
> 
> We have setup dhcp/tftp on debian 2.2 and things are working fine with a
> linux kernel tagged with mknbi-linux.
> 
> We need to run a progarm called memtest86 which runs stand alone, i.e., it
> is completely contained in a bootable image. Its booting procedure is
> based on _very_ old linux kernels. And many signatures and magic numbers
> seem to be minix compliant. Therefore mknbi-linux doesn't work.

The attached patch to memtest86-2.5 builds it as an ELF image.
Etherboot cannot load an unpatched image memtest86 loads to low in
memory.

I have used this succesfully with the 4.6.10 with Multiboot support
compiled it.


Eric

diff -uNr memtest86-2.5/Makefile memtest86-2.5.eb3/Makefile
--- memtest86-2.5/Makefile	Thu Sep 21 17:39:19 2000
+++ memtest86-2.5.eb3/Makefile	Wed Mar 21 21:44:37 2001
@@ -43,6 +43,9 @@
 memtest.bin: setup bootsect head.out relo.out build
 	./build bootsect setup head.out relo.out >memtest.bin
 
+memtest86.ebi: head.obj relo.obj memtest86.lds
+	ld -T memtest86.lds head.obj relo.obj -o $@
+
 test.o: test.c test.h defs.h config.h
 	$(CC) -c $(CCFLAGS) test.c
 
@@ -69,12 +72,16 @@
 	    $(OBJCOPY) relo relo.out; \
 	fi
 
+relo.obj: relo.out
+	ld -r -o $@ -T relo.lds -b binary $^
+
 head.o: head.s
 	as -o $@ $<
 
 head: $(OBJS)
 	ld -m elf_i386 -o $@ -e do_test -Ttext $(TXT_ADR) -Tdata $(DAT_ADR) \
 		-Map mapfile $(OBJS)
+
 head.out: head
 	if hash encaps 2> /dev/null; then \
 	    $(OBJDUMP) -o $(TXT_ADR) head >head.out; \
@@ -82,6 +89,9 @@
 	    $(OBJCOPY) head head.out; \
 	fi
 
+head.obj: head.out
+	ld -r -o $@ -T head.lds -b binary $^
+
 head.s: head.S test.h
 	$(CC) -E -traditional $< -o $@
 
@@ -108,7 +118,7 @@
 
 clean:
 	rm -f *.o *.s build memtest.bin bootsect setup head head.out mapfile relo \
-	      relo.out mapfile.relo
+	      relo.out mapfile.relo memtest86.ebi *.obj
 
 install: all
 	dd <memtest.bin >$(FDISK) bs=8192
Binary files memtest86-2.5/core and memtest86-2.5.eb3/core differ
diff -uNr memtest86-2.5/defs.h memtest86-2.5.eb3/defs.h
--- memtest86-2.5/defs.h	Thu Sep 21 17:39:16 2000
+++ memtest86-2.5.eb3/defs.h	Wed Mar 21 21:42:05 2001
@@ -8,7 +8,7 @@
 
 /*
  * Caution!! Do not change TESTADR, MAINSZ, TESTSZ or RELOBASE without also
- * editing the Makefile.
+ * editing the Makefile & memtest86.lds.
  */
 #define TESTADR		0x1000		/* Final adrs for the test code */
 #define MAINSZ		0x8800		/* Size of primary test code */
diff -uNr memtest86-2.5/head.S memtest86-2.5.eb3/head.S
--- memtest86-2.5/head.S	Thu Sep 21 16:48:25 2000
+++ memtest86-2.5.eb3/head.S	Wed Mar 21 21:56:03 2001
@@ -59,12 +59,6 @@
 
 	cld
 	cli
-	movl $(KERNEL_DS),%eax
-	mov %ax,%ds
-	mov %ax,%es
-	mov %ax,%fs
-	mov %ax,%gs
-	mov %ax,%ss
 	mov $(TESTADR),%esp
 /*
  * start system 32-bit setup. We need to re-do some of the things done
diff -uNr memtest86-2.5/head.lds memtest86-2.5.eb3/head.lds
--- memtest86-2.5/head.lds	Wed Dec 31 17:00:00 1969
+++ memtest86-2.5.eb3/head.lds	Wed Mar 21 21:30:04 2001
@@ -0,0 +1,5 @@
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+SECTIONS {
+	.head : { *(*) }
+}
diff -uNr memtest86-2.5/lib.c memtest86-2.5.eb3/lib.c
--- memtest86-2.5/lib.c	Wed Oct 18 12:57:40 2000
+++ memtest86-2.5.eb3/lib.c	Fri Mar 30 10:42:37 2001
@@ -839,8 +839,13 @@
 	/* now do hardwired init */
 	serial_echo_outb(0x03, UART_LCR); /* No parity, 8 data bits, 1 stop */
 	serial_echo_outb(0x83, UART_LCR); /* Access divisor latch */
+#if 1
 	serial_echo_outb(0x00, UART_DLM); /* 9600 baud */
 	serial_echo_outb(0x0c, UART_DLL);
+#else
+	serial_echo_outb(0x00, UART_DLM); /* 115200 baud */
+	serial_echo_outb(0x01, UART_DLL);
+#endif
 	serial_echo_outb(0x03, UART_LCR); /* Done with divisor */
 
 	/* Prior to disabling interrupts, read the LSR and RBR
diff -uNr memtest86-2.5/main.c memtest86-2.5.eb3/main.c
--- memtest86-2.5/main.c	Fri Oct 20 16:51:49 2000
+++ memtest86-2.5.eb3/main.c	Fri Mar 30 10:38:44 2001
@@ -66,6 +66,12 @@
 
 	/* Set pointer to common variable area */
 	v = (struct vars *)(TESTADR+TSTSIZE-0x400);
+	if (&segs > (int *)RELOBASE) {
+		v = (struct vars *)(RELOBASE+TESTADR+TSTSIZE-0x400);
+		if (v->firsttime == 0) {
+			restart();
+		}
+	}
 
 	/* If first time, initialize test */
 	if (v->firsttime == 0) {
@@ -392,7 +398,8 @@
         for(i=0, pp=(char *)(SCREEN_ADR+0); i<80*24; i++, pp+=2) {
                 *pp = ' ';
         }
-	do_test();
+	p = (unsigned long *)TESTADR;
+	goto *p;
 }
 
 /* Compute the total number of ticks per pass */
diff -uNr memtest86-2.5/memtest86.lds memtest86-2.5.eb3/memtest86.lds
--- memtest86-2.5/memtest86.lds	Wed Dec 31 17:00:00 1969
+++ memtest86-2.5.eb3/memtest86.lds	Fri Mar 30 10:37:40 2001
@@ -0,0 +1,26 @@
+__testadr = 0x1000;
+__reloadr = 0x9800;
+__zeroadr = 0x12000;
+__zerosz  = 0x400;
+__relobase = 0x100000;
+__start = __relobase + __reloadr;
+/*
+__relobase = 0;
+__start = __testadr;
+*/
+
+
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+PHDRS { 
+	head PT_LOAD ;
+	relo PT_LOAD ;
+	zero PT_LOAD ;
+}
+ENTRY(__start);
+
+SECTIONS {
+	.head (__testadr + __relobase): { *(.head) } : head
+	.relo (__reloadr + __relobase): { *(.relo) } : relo
+	.zero (__zeroadr + __relobase): { . = . + __zerosz; nothing = . ; } : zero
+}
diff -uNr memtest86-2.5/relo.lds memtest86-2.5.eb3/relo.lds
--- memtest86-2.5/relo.lds	Wed Dec 31 17:00:00 1969
+++ memtest86-2.5.eb3/relo.lds	Wed Mar 21 21:29:50 2001
@@ -0,0 +1,5 @@
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+SECTIONS {
+	.relo : { *(*) }
+}
diff -uNr memtest86-2.5/setup.S memtest86-2.5.eb3/setup.S
--- memtest86-2.5/setup.S	Wed Sep 20 12:08:11 2000
+++ memtest86-2.5.eb3/setup.S	Wed Mar 21 21:10:16 2001
@@ -128,7 +128,12 @@
 flush_instr:
 	mov	ax,#KERNEL_DS
 	mov	ds,ax
+	mov	es,ax
 	mov	ss,ax
+	mov	fs,ax
+	mov	gs,ax
+
+! Clear the video display
 	mov	ax,#0x0720
 	mov	ebx,#0xb8000
 	mov	ecx,#0xc0000

Re: [Etherboot-developers] booting non linux images

[Anuradha R. <anu...@gn...>]

On 12 May 2001, Eric W. Biederman wrote:

> The attached patch to memtest86-2.5 builds it as an ELF image.
> Etherboot cannot load an unpatched image memtest86 loads to low in
> memory.
> 
> I have used this succesfully with the 4.6.10 with Multiboot support
> compiled it.

The patch applies neatly and memtest86.bin builds fine. But making
memtest86.ebi stops with a link error.

ld -T memtest86.lds head.obj relo.obj -o memtest86.ebi
ld: bfd assertion fail ../../bfd/elf.c:1405
ld: bfd assertion fail ../../bfd/elf.c:1405
relo.obj: file not recognized: File format not recognized
make: *** [memtest86.ebi] Error 1

Any clue?

Sorry for going stightly off topic.

Thanks in advance.

Anuradha

Re: [Etherboot-developers] booting non linux images

[<ebi...@ln...>]

Anuradha Ratnaweera <anu...@gn...> writes:

> On 12 May 2001, Eric W. Biederman wrote:
> 
> > The attached patch to memtest86-2.5 builds it as an ELF image.
> > Etherboot cannot load an unpatched image memtest86 loads to low in
> > memory.
> > 
> > I have used this succesfully with the 4.6.10 with Multiboot support
> > compiled it.
> 
> The patch applies neatly and memtest86.bin builds fine. But making
> memtest86.ebi stops with a link error.
> 
> ld -T memtest86.lds head.obj relo.obj -o memtest86.ebi
> ld: bfd assertion fail ../../bfd/elf.c:1405
> ld: bfd assertion fail ../../bfd/elf.c:1405
> relo.obj: file not recognized: File format not recognized
> make: *** [memtest86.ebi] Error 1
> 
> Any clue?

Grr yes.  Your version of ld is buggy.
I have seen this once before.  If I could figure out how
to make it work with your version of ld I would.

I think I have a bad choice of names in relo.obj.  Because
except for names relo.obj and head.obj are exactly identical.

What I am currently running is:
GNU ld 2.10.90
Copyright 2000 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License.  This program has absolutely no warranty.
  Supported emulations:
   elf_i386
   i386linux


Eric