[PATCH] powerpc: Add mktree utility to arch/powerpc/boot

[PATCH] powerpc: Add mktree utility to arch/powerpc/boot

[Josh Boyer]

This patch adds the mktree program that is needed to post process zImage
wrappers for various PowerPC 4xx boards

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

---
 arch/powerpc/boot/Makefile |    4 -
 arch/powerpc/boot/mktree.c |  152 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 154 insertions(+), 2 deletions(-)

--- linux-2.6.orig/arch/powerpc/boot/Makefile
+++ linux-2.6/arch/powerpc/boot/Makefile
@@ -94,13 +94,13 @@ $(patsubst %.S,%.o, $(filter %.S, $(src-
 $(obj)/wrapper.a: $(obj-wlib)
 	$(call cmd,bootar)
 
-hostprogs-y	:= addnote addRamDisk hack-coff
+hostprogs-y	:= addnote addRamDisk hack-coff mktree
 
 extra-y		:= $(obj)/crt0.o $(obj)/wrapper.a $(obj-plat) $(obj)/empty.o \
 		   $(obj)/zImage.lds $(obj)/zImage.coff.lds
 
 wrapper		:=$(srctree)/$(src)/wrapper
-wrapperbits	:= $(extra-y) $(addprefix $(obj)/,addnote hack-coff)
+wrapperbits	:= $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree)
 
 #############
 # Bits for building various flavours of zImage
--- /dev/null
+++ linux-2.6/arch/powerpc/boot/mktree.c
@@ -0,0 +1,152 @@
+/*
+ * Makes a tree bootable image for IBM Evaluation boards.
+ * Basically, just take a zImage, skip the ELF header, and stuff
+ * a 32 byte header on the front.
+ *
+ * We use htonl, which is a network macro, to make sure we're doing
+ * The Right Thing on an LE machine.  It's non-obvious, but it should
+ * work on anything BSD'ish.
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#ifdef __sun__
+#include <inttypes.h>
+#else
+#include <stdint.h>
+#endif
+
+/* This gets tacked on the front of the image.  There are also a few
+ * bytes allocated after the _start label used by the boot rom (see
+ * head.S for details).
+ */
+typedef struct boot_block {
+	uint32_t bb_magic;		/* 0x0052504F */
+	uint32_t bb_dest;		/* Target address of the image */
+	uint32_t bb_num_512blocks;	/* Size, rounded-up, in 512 byte blks */
+	uint32_t bb_debug_flag;	/* Run debugger or image after load */
+	uint32_t bb_entry_point;	/* The image address to start */
+	uint32_t bb_checksum;	/* 32 bit checksum including header */
+	uint32_t reserved[2];
+} boot_block_t;
+
+#define IMGBLK	512
+char	tmpbuf[IMGBLK];
+
+int main(int argc, char *argv[])
+{
+	int	in_fd, out_fd;
+	int	nblks, i;
+	uint	cksum, *cp;
+	struct	stat	st;
+	boot_block_t	bt;
+
+	if (argc < 3) {
+		fprintf(stderr, "usage: %s <zImage-file> <boot-image> [entry-point]\n",argv[0]);
+		exit(1);
+	}
+
+	if (stat(argv[1], &st) < 0) {
+		perror("stat");
+		exit(2);
+	}
+
+	nblks = (st.st_size + IMGBLK) / IMGBLK;
+
+	bt.bb_magic = htonl(0x0052504F);
+
+	/* If we have the optional entry point parameter, use it */
+	if (argc == 4)
+		bt.bb_dest = bt.bb_entry_point = htonl(strtoul(argv[3], NULL, 0));
+	else
+		bt.bb_dest = bt.bb_entry_point = htonl(0x500000);
+
+	/* We know these from the linker command.
+	 * ...and then move it up into memory a little more so the
+	 * relocation can happen.
+	 */
+	bt.bb_num_512blocks = htonl(nblks);
+	bt.bb_debug_flag = 0;
+
+	bt.bb_checksum = 0;
+
+	/* To be neat and tidy :-).
+	*/
+	bt.reserved[0] = 0;
+	bt.reserved[1] = 0;
+
+	if ((in_fd = open(argv[1], O_RDONLY)) < 0) {
+		perror("zImage open");
+		exit(3);
+	}
+
+	if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) {
+		perror("bootfile open");
+		exit(3);
+	}
+
+	cksum = 0;
+	cp = (void *)&bt;
+	for (i=0; i<sizeof(bt)/sizeof(uint); i++)
+		cksum += *cp++;
+
+	/* Assume zImage is an ELF file, and skip the 64K header.
+	*/
+	if (read(in_fd, tmpbuf, IMGBLK) != IMGBLK) {
+		fprintf(stderr, "%s is too small to be an ELF image\n",
+				argv[1]);
+		exit(4);
+	}
+
+	if ((*(uint *)tmpbuf) != htonl(0x7f454c46)) {
+		fprintf(stderr, "%s is not an ELF image\n", argv[1]);
+		exit(4);
+	}
+
+	if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) {
+		fprintf(stderr, "%s failed to seek in ELF image\n", argv[1]);
+		exit(4);
+	}
+
+	nblks -= (64 * 1024) / IMGBLK;
+
+	/* And away we go......
+	*/
+	if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
+		perror("boot-image write");
+		exit(5);
+	}
+
+	while (nblks-- > 0) {
+		if (read(in_fd, tmpbuf, IMGBLK) < 0) {
+			perror("zImage read");
+			exit(5);
+		}
+		cp = (uint *)tmpbuf;
+		for (i=0; i<sizeof(tmpbuf)/sizeof(uint); i++)
+			cksum += *cp++;
+		if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) {
+			perror("boot-image write");
+			exit(5);
+		}
+	}
+
+	/* rewrite the header with the computed checksum.
+	*/
+	bt.bb_checksum = htonl(cksum);
+	if (lseek(out_fd, 0, SEEK_SET) < 0) {
+		perror("rewrite seek");
+		exit(1);
+	}
+	if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
+		perror("boot-image rewrite");
+		exit(1);
+	}
+
+	exit(0);
+}

Re: [PATCH] powerpc: Add mktree utility to arch/powerpc/boot

[Geoff Levand]

Josh Boyer wrote:
> + * Makes a tree bootable image for IBM Evaluation boards.
> + * Basically, just take a zImage, skip the ELF header, and stuff
> + * a 32 byte header on the front.

I guess you mean on some standard bootloader that comes with
IBM Evaluation boards?  Should this comment reflect that this
operation is required by that bootloader, not the hardware?

-Geoff

Re: [PATCH] powerpc: Add mktree utility to arch/powerpc/boot

[Josh Boyer]

On Fri, 2006-10-13 at 09:14 -0700, Geoff Levand wrote:
> Josh Boyer wrote:
> > + * Makes a tree bootable image for IBM Evaluation boards.
> > + * Basically, just take a zImage, skip the ELF header, and stuff
> > + * a 32 byte header on the front.
> 
> I guess you mean on some standard bootloader that comes with
> IBM Evaluation boards?  Should this comment reflect that this
> operation is required by that bootloader, not the hardware?

Yes, this is needed for the standard bootloader on some boards.
However, neither the bootloader or the HW are doing what the comment
says.  That is what mktree.c itself does, so I think it's correctly
describing what's going on.

BTW, this is simply a copy of the mktree.c that's been in
arch/ppc/boot/simple for years.  I'm simply adding it to arch/powerpc in
preparation for some more 4xx merge work to follow.

josh

Re: [PATCH] powerpc: Add mktree utility to arch/powerpc/boot

[Josh Boyer]

On Fri, 2006-10-13 at 09:14 -0700, Geoff Levand wrote:
> Josh Boyer wrote:
> > + * Makes a tree bootable image for IBM Evaluation boards.
> > + * Basically, just take a zImage, skip the ELF header, and stuff
> > + * a 32 byte header on the front.
> 
> I guess you mean on some standard bootloader that comes with
> IBM Evaluation boards?  Should this comment reflect that this
> operation is required by that bootloader, not the hardware?

Yes, this is needed for the standard bootloader on some boards.
However, neither the bootloader or the HW are doing what the comment
says.  That is what mktree.c itself does, so I think it's correctly
describing what's going on.

BTW, this is simply a copy of the mktree.c that's been in
arch/ppc/boot/simple for years.  I'm simply adding it to arch/powerpc in
preparation for some more 4xx merge work to follow.

josh