[U-Boot] [PATCH] cmd_elf: CONFIG_ELF_SIMPLE_LOAD: load ELFs according to PHDRs

[U-Boot] [PATCH] cmd_elf: CONFIG_ELF_SIMPLE_LOAD: load ELFs according to PHDRs

[Mike Frysinger]

The current ELF loading function does a lot of work above and beyond a
simple "loading".  It ignores the real load addresses and loads things into
their virtual (runtime) address.  This is undesirable when we just want it
to load an ELF and let the ELF do the actual C runtime init.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 common/cmd_elf.c |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index 3ebb6d9..7b82749 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -276,6 +276,32 @@ int valid_elf_image (unsigned long addr)
  * A very simple elf loader, assumes the image is valid, returns the
  * entry point address.
  * ====================================================================== */
+#ifdef CONFIG_ELF_SIMPLE_LOAD
+unsigned long load_elf_image (unsigned long addr)
+{
+	Elf32_Ehdr *ehdr;
+	Elf32_Phdr *phdr;
+	unsigned long entry;
+	size_t i;
+
+	ehdr = (Elf32_Ehdr *) addr;
+	phdr = (Elf32_Phdr *) (addr + ehdr->e_phoff);
+
+	entry = ehdr->e_entry;
+
+	/* Load each program header */
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		void *dst = (void *) phdr->p_paddr;
+		void *src = (void *) addr + phdr->p_offset;
+		printf ("Loading phdr %i to 0x%p (%i bytes)\n",
+		        i, dst, phdr->p_filesz);
+		memcpy (dst, src, phdr->p_filesz);
+		++phdr;
+	}
+
+	return entry;
+}
+#else
 unsigned long load_elf_image (unsigned long addr)
 {
 	Elf32_Ehdr *ehdr;		/* Elf header structure pointer     */
@@ -327,6 +353,7 @@ unsigned long load_elf_image (unsigned long addr)
 
 	return ehdr->e_entry;
 }
+#endif
 
 /* ====================================================================== */
 U_BOOT_CMD(
-- 
1.6.0.3

[U-Boot] [PATCH] cmd_elf: CONFIG_ELF_SIMPLE_LOAD: load ELFs according to PHDRs

[Wolfgang Denk]

Dear Mike,

In message <1225603202-5757-1-git-send-email-vapier@gentoo.org> you wrote:
> The current ELF loading function does a lot of work above and beyond a
> simple "loading".  It ignores the real load addresses and loads things into
> their virtual (runtime) address.  This is undesirable when we just want it
> to load an ELF and let the ELF do the actual C runtime init.

I apologize for the late review...


> +#ifdef CONFIG_ELF_SIMPLE_LOAD
> +unsigned long load_elf_image (unsigned long addr)
...

...but would it not make sense to allow to make the decision which
behaviour fits the user's requirements at runtime instead of compile
time?

We could either make this depend on some environment variable setting,
or on a command line option when running the command.


If you prefer to stick with the CONFIG_ELF_SIMPLE_LOAD solution, then
this variable has to be documented in the README.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The Gates in my computer are AND, OR and NOT; they are not Bill.

[U-Boot] [PATCH] cmd_elf: CONFIG_ELF_SIMPLE_LOAD: load ELFs according to PHDRs

[Mike Frysinger]

On Friday 05 December 2008 17:21:27 Wolfgang Denk wrote:
> In message <1225603202-5757-1-git-send-email-vapier@gentoo.org> you wrote:
> > The current ELF loading function does a lot of work above and beyond a
> > simple "loading".  It ignores the real load addresses and loads things
> > into their virtual (runtime) address.  This is undesirable when we just
> > want it to load an ELF and let the ELF do the actual C runtime init.
>
> I apologize for the late review...
>
> > +#ifdef CONFIG_ELF_SIMPLE_LOAD
> > +unsigned long load_elf_image (unsigned long addr)
>
> ...
>
> ...but would it not make sense to allow to make the decision which
> behaviour fits the user's requirements at runtime instead of compile
> time?
>
> We could either make this depend on some environment variable setting,
> or on a command line option when running the command.
>
>
> If you prefer to stick with the CONFIG_ELF_SIMPLE_LOAD solution, then
> this variable has to be documented in the README.

it doesnt matter to me which route is taken so long as the default can be 
controlled (so via env is ok as you can set the default env values).  if you 
prefer one over the other, let me know.  otherwise simply updating the README 
is the easiest route for me ...
-mike
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[U-Boot] [PATCH] cmd_elf: CONFIG_ELF_SIMPLE_LOAD: load ELFs according to PHDRs

[Wolfgang Denk]

Dear Mike,

in message <200812052002.18103.vapier@gentoo.org> you wrote:
>
> > ...but would it not make sense to allow to make the decision which
> > behaviour fits the user's requirements at runtime instead of compile
> > time?
> >
> > We could either make this depend on some environment variable setting,
> > or on a command line option when running the command.
> >
> >
> > If you prefer to stick with the CONFIG_ELF_SIMPLE_LOAD solution, then
> > this variable has to be documented in the README.
>
> it doesnt matter to me which route is taken so long as the default can be 
> controlled (so via env is ok as you can set the default env values).  if you 
> prefer one over the other, let me know.  otherwise simply updating the README 
> is the easiest route for me ...

Well, my preference is a command line option; I think we should move
into that direction instead of adding more and more magic environment
variables.

But if you submit a patch that uses environment variables I would not
object either.


Thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
To the systems programmer,  users  and  applications  serve  only  to
provide a test load.

[U-Boot] [PATCH] cmd_elf: add an option for loading ELFs according to PHDRs

[Mike Frysinger]

The current ELF loading function does a lot of work above and beyond a
simple "loading".  It ignores the real load addresses and loads things
into their virtual (runtime) address.  This is undesirable when we just
want it to load an ELF and let the ELF do the actual C runtime init.

So add a command line option to let people choose to load via either the
program or section headers.  I'd prefer to have program header loading
be the default, but this would break historical behavior, so I'll leave
section header loading as the norm.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 common/cmd_elf.c |   62 ++++++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index 104d6e6..bf32612 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -25,7 +25,8 @@ DECLARE_GLOBAL_DATA_PTR;
 #endif
 
 int valid_elf_image (unsigned long addr);
-unsigned long load_elf_image (unsigned long addr);
+static unsigned long load_elf_image_phdr(unsigned long addr);
+static unsigned long load_elf_image_shdr(unsigned long addr);
 
 /* Allow ports to override the default behavior */
 __attribute__((weak))
@@ -61,19 +62,34 @@ int do_bootelf (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	unsigned long addr;		/* Address of the ELF image     */
 	unsigned long rc;		/* Return value from user code  */
+	char *sload, *saddr;
 
 	/* -------------------------------------------------- */
 	int rcode = 0;
 
-	if (argc < 2)
-		addr = load_addr;
+	sload = saddr = NULL;
+	if (argc == 3) {
+		sload = argv[1];
+		saddr = argv[2];
+	} else if (argc == 2) {
+		if (argv[1][0] == '-')
+			sload = argv[1];
+		else
+			saddr = argv[1];
+	}
+
+	if (saddr)
+		addr = simple_strtoul(saddr, NULL, 16);
 	else
-		addr = simple_strtoul (argv[1], NULL, 16);
+		addr = load_addr;
 
 	if (!valid_elf_image (addr))
 		return 1;
 
-	addr = load_elf_image (addr);
+	if (sload && sload[1] == 'p')
+		addr = load_elf_image_phdr(addr);
+	else
+		addr = load_elf_image_shdr(addr);
 
 	printf ("## Starting application@0x%08lx ...\n", addr);
 
@@ -204,7 +220,7 @@ int do_bootvx (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	 */
 
 	if (valid_elf_image (addr)) {
-		addr = load_elf_image (addr);
+		addr = load_elf_image_shdr (addr);
 	} else {
 		puts ("## Not an ELF image, assuming binary\n");
 		/* leave addr as load_addr */
@@ -258,7 +274,33 @@ int valid_elf_image (unsigned long addr)
  * A very simple elf loader, assumes the image is valid, returns the
  * entry point address.
  * ====================================================================== */
-unsigned long load_elf_image (unsigned long addr)
+static unsigned long load_elf_image_phdr(unsigned long addr)
+{
+	Elf32_Ehdr *ehdr;		/* Elf header structure pointer     */
+	Elf32_Phdr *phdr;		/* Program header structure pointer */
+	int i;
+
+	ehdr = (Elf32_Ehdr *) addr;
+	phdr = (Elf32_Phdr *) (addr + ehdr->e_phoff);
+
+	/* Load each program header */
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		void *dst = (void *) phdr->p_paddr;
+		void *src = (void *) addr + phdr->p_offset;
+		debug("Loading phdr %i to 0x%p (%i bytes)\n",
+			i, dst, phdr->p_filesz);
+		if (phdr->p_filesz)
+			memcpy(dst, src, phdr->p_filesz);
+		if (phdr->p_filesz != phdr->p_memsz)
+			memset(dst + phdr->p_filesz, 0x00, phdr->p_memsz - phdr->p_filesz);
+		flush_cache((unsigned long)dst, phdr->p_filesz);
+		++phdr;
+	}
+
+	return ehdr->e_entry;
+}
+
+static unsigned long load_elf_image_shdr(unsigned long addr)
 {
 	Elf32_Ehdr *ehdr;		/* Elf header structure pointer     */
 	Elf32_Shdr *shdr;		/* Section header structure pointer */
@@ -312,9 +354,11 @@ unsigned long load_elf_image (unsigned long addr)
 
 /* ====================================================================== */
 U_BOOT_CMD(
-	bootelf,      2,      0,      do_bootelf,
+	bootelf,      3,      0,      do_bootelf,
 	"Boot from an ELF image in memory",
-	" [address] - load address of ELF image."
+	"[-p|-s] [address]\n"
+	"\t- load ELF image at [address] via program headers (-p)\n"
+	"\t  or via section headers (-s)"
 );
 
 U_BOOT_CMD(
-- 
1.7.3.1

[U-Boot] [PATCH] cmd_elf: add an option for loading ELFs according to PHDRs

[Wolfgang Denk]

Dear Mike Frysinger,

In message <1286048693-1773-1-git-send-email-vapier@gentoo.org> you wrote:
> The current ELF loading function does a lot of work above and beyond a
> simple "loading".  It ignores the real load addresses and loads things
> into their virtual (runtime) address.  This is undesirable when we just
> want it to load an ELF and let the ELF do the actual C runtime init.
> 
> So add a command line option to let people choose to load via either the
> program or section headers.  I'd prefer to have program header loading
> be the default, but this would break historical behavior, so I'll leave
> section header loading as the norm.
> 
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> ---
>  common/cmd_elf.c |   62 ++++++++++++++++++++++++++++++++++++++++++++++-------
>  1 files changed, 53 insertions(+), 9 deletions(-)

Applied, thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
When properly administered, vacations do not  diminish  productivity:
for every week you're away and get nothing done, there's another when
your boss is away and you get twice as much done.  -- Daniel B. Luten