[RFC 0/2] syslinux: Add device tree support

[RFC 0/2] syslinux: Add device tree support

[Thierry Reding]

This patch series adds support for passing a Flattened Device Tree (FDT)
blob to the Linux kernel. Currently, only the linux.c32 module can do so
and some additional checking should be done to only pass the blob if the
kernel supports boot protocol 2.09 or later.

Thierry

Thierry Reding (2):
  com32: Add device tree support
  linux.c32: Add initrd= parameter

 com32/gfxboot/gfxboot.c         |    2 +-
 com32/include/syslinux/linux.h  |   25 +++++++++++++++++++++++-
 com32/lib/Makefile              |    4 +++-
 com32/lib/syslinux/fdt.c        |   28 ++++++++++++++++++++++++++
 com32/lib/syslinux/load_linux.c |   41 ++++++++++++++++++++++++++++++++++++++-
 com32/lua/src/syslinux.c        |    4 ++--
 com32/modules/linux.c           |   20 ++++++++++++++++++-
 7 files changed, 117 insertions(+), 7 deletions(-)
 create mode 100644 com32/lib/syslinux/fdt.c

-- 
1.7.10.2

[RFC 1/2] com32: Add device tree support

[Thierry Reding]

This commit adds support for passing a Flattened Device Tree (FDT) blob
to the Linux kernel.

Signed-off-by: Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>
---
 com32/gfxboot/gfxboot.c         |    2 +-
 com32/include/syslinux/linux.h  |   25 +++++++++++++++++++++++-
 com32/lib/Makefile              |    4 +++-
 com32/lib/syslinux/fdt.c        |   28 ++++++++++++++++++++++++++
 com32/lib/syslinux/load_linux.c |   41 ++++++++++++++++++++++++++++++++++++++-
 com32/lua/src/syslinux.c        |    4 ++--
 6 files changed, 98 insertions(+), 6 deletions(-)
 create mode 100644 com32/lib/syslinux/fdt.c

diff --git a/com32/gfxboot/gfxboot.c b/com32/gfxboot/gfxboot.c
index 35d180a..aa05caf 100644
--- a/com32/gfxboot/gfxboot.c
+++ b/com32/gfxboot/gfxboot.c
@@ -962,7 +962,7 @@ void boot_entry(menu_t *menu_ptr, char *arg)
 
   gfx_done();
 
-  syslinux_boot_linux(kernel, kernel_size, initrd, arg);
+  syslinux_boot_linux(kernel, kernel_size, initrd, NULL, arg);
 }
 
 
diff --git a/com32/include/syslinux/linux.h b/com32/include/syslinux/linux.h
index 754d1b6..6a5c2db 100644
--- a/com32/include/syslinux/linux.h
+++ b/com32/include/syslinux/linux.h
@@ -51,8 +51,26 @@ struct initramfs {
 };
 #define INITRAMFS_MAX_ALIGN	4096
 
+struct fdt {
+	void *data;
+	size_t len;
+};
+#define DEVICETREE_MAX_ALIGN	4096
+
+struct setup_data {
+	uint64_t next;
+	uint32_t type;
+	uint32_t len;
+	uint8_t data[0];
+};
+
+#define SETUP_NONE	0
+#define SETUP_E820_EXT	1
+#define SETUP_DTB	2
+
 int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
-			struct initramfs *initramfs, char *cmdline);
+			struct initramfs *initramfs, struct fdt *fdt,
+			char *cmdline);
 
 /* Initramfs manipulation functions */
 
@@ -70,4 +88,9 @@ int initramfs_load_file(struct initramfs *ihead, const char *src_filename,
 int initramfs_add_trailer(struct initramfs *ihead);
 int initramfs_load_archive(struct initramfs *ihead, const char *filename);
 
+/* Device Tree manipulation functions */
+
+struct fdt *fdt_init(void);
+int fdt_load(struct fdt *fdt, const char *filename);
+
 #endif /* _SYSLINUX_LINUX_H */
diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index eace321..a4959f6 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -129,7 +129,9 @@ LIBOBJS = \
 	syslinux/video/fontquery.o syslinux/video/forcetext.o		\
 	syslinux/video/reportmode.o					\
 	\
-	syslinux/disk.o
+	syslinux/disk.o							\
+	\
+	syslinux/fdt.o
 
 # These are the objects which are also imported into the core
 LIBCOREOBJS = 	\
diff --git a/com32/lib/syslinux/fdt.c b/com32/lib/syslinux/fdt.c
new file mode 100644
index 0000000..1bcd90b
--- /dev/null
+++ b/com32/lib/syslinux/fdt.c
@@ -0,0 +1,28 @@
+#include <stdlib.h>
+#include <syslinux/linux.h>
+#include <syslinux/loadfile.h>
+
+struct fdt *fdt_init(void)
+{
+	struct fdt *fdt;
+
+	fdt = calloc(1, sizeof(*fdt));
+	if (!fdt)
+		return NULL;
+
+	return fdt;
+}
+
+int fdt_load(struct fdt *fdt, const char *filename)
+{
+	void *data;
+	size_t len;
+
+	if (loadfile(filename, &data, &len))
+		return -1;
+
+	fdt->data = data;
+	fdt->len = len;
+
+	return 0;
+}
diff --git a/com32/lib/syslinux/load_linux.c b/com32/lib/syslinux/load_linux.c
index 45cd696..b68aef7 100644
--- a/com32/lib/syslinux/load_linux.c
+++ b/com32/lib/syslinux/load_linux.c
@@ -180,7 +180,8 @@ static int map_initramfs(struct syslinux_movelist **fraglist,
 }
 
 int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
-			struct initramfs *initramfs, char *cmdline)
+			struct initramfs *initramfs, struct fdt *fdt,
+			char *cmdline)
 {
     struct linux_header hdr, *whdr;
     size_t real_mode_size, prot_mode_size;
@@ -449,6 +450,44 @@ int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
 	}
     }
 
+    if (fdt && fdt->len > 0) {
+	const addr_t align_mask = DEVICETREE_MAX_ALIGN - 1;
+	struct syslinux_memmap *ml;
+	struct setup_data *setup;
+	addr_t best_addr = 0;
+	size_t size;
+
+	size = sizeof(*setup) + fdt->len;
+
+	setup = malloc(size);
+	if (!setup)
+		goto bail;
+
+	setup->next = 0;
+	setup->type = SETUP_DTB;
+	setup->len = fdt->len;
+	memcpy(setup->data, fdt->data, fdt->len);
+
+	for (ml = amap; ml->type != SMT_END; ml = ml->next) {
+		addr_t adj_start = (ml->start + align_mask) & ~align_mask;
+		addr_t adj_end = ml->next->start & ~align_mask;
+
+		if (ml->type == SMT_FREE && adj_end - adj_start >= size)
+			best_addr = (adj_end - size) & ~align_mask;
+	}
+
+	if (!best_addr)
+		goto bail;
+
+	whdr->setup_data = best_addr;
+
+	if (syslinux_add_memmap(&amap, best_addr, size, SMT_ALLOC))
+	    goto bail;
+
+	if (syslinux_add_movelist(&fraglist, best_addr, (addr_t) setup, size))
+	    goto bail;
+    }
+
     /* Set up the registers on entry */
     memset(&regs, 0, sizeof regs);
     regs.es = regs.ds = regs.ss = regs.fs = regs.gs = real_mode_base >> 4;
diff --git a/com32/lua/src/syslinux.c b/com32/lua/src/syslinux.c
index 9b207db..af5db83 100644
--- a/com32/lua/src/syslinux.c
+++ b/com32/lua/src/syslinux.c
@@ -278,7 +278,7 @@ static int sl_boot_linux(lua_State * L)
        msleep(10000);
      */
 
-    ret = syslinux_boot_linux(kernel_data, kernel_len, initramfs, newcmdline);
+    ret = syslinux_boot_linux(kernel_data, kernel_len, initramfs, NULL, newcmdline);
 
     printf("syslinux_boot_linux returned %d\n", ret);
 
@@ -405,7 +405,7 @@ static int sl_boot_it(lua_State * L)
     (void)mem_limit;
 
     return syslinux_boot_linux(kernel->data, kernel->size,
-			       initramfs, (char *)cmdline);
+			       initramfs, NULL, (char *)cmdline);
 }
 
 static int sl_derivative(lua_State * L)
-- 
1.7.10.2

[RFC 2/2] linux.c32: Add initrd= parameter

[Thierry Reding]

This new parameter can be used to specify a Flattened Device Tree (FDT)
blob to pass to the Linux kernel.

Signed-off-by: Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>
---
 com32/modules/linux.c |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/com32/modules/linux.c b/com32/modules/linux.c
index b902ebc..cc1e6fe 100644
--- a/com32/modules/linux.c
+++ b/com32/modules/linux.c
@@ -112,6 +112,7 @@ int main(int argc, char *argv[])
 {
     const char *kernel_name;
     struct initramfs *initramfs;
+    struct fdt *fdt;
     char *cmdline;
     char *boot_image;
     void *kernel_data;
@@ -207,8 +208,25 @@ int main(int argc, char *argv[])
 	    goto bail;
     }
 
+    fdt = fdt_init();
+    if (!fdt)
+	goto bail;
+
+    if ((arg = find_argument(argp, "fdt="))) {
+	if (!opt_quiet)
+	    printf("Loading %s... ", arg);
+
+	if (fdt_load(fdt, arg)) {
+	    printf("failed!\n");
+	    goto bail;
+	}
+
+	if (!opt_quiet)
+	    printf("ok\n");
+    }
+
     /* This should not return... */
-    syslinux_boot_linux(kernel_data, kernel_len, initramfs, cmdline);
+    syslinux_boot_linux(kernel_data, kernel_len, initramfs, fdt, cmdline);
 
 bail:
     fprintf(stderr, "Kernel load failure (insufficient memory?)\n");
-- 
1.7.10.2

Re: [syslinux] [RFC 0/2] syslinux: Add device tree support

[H. Peter Anvin]

On 05/31/2012 08:41 AM, Thierry Reding wrote:
> This patch series adds support for passing a Flattened Device Tree (FDT)
> blob to the Linux kernel. Currently, only the linux.c32 module can do so
> and some additional checking should be done to only pass the blob if the
> kernel supports boot protocol 2.09 or later.
> 
> Thierry

Hi there,

I just merged a modified/more generic version of your patch.  I would
appreciate it if you could test it and report back.

	-hpa

Re: [syslinux] [RFC 0/2] syslinux: Add device tree support

[Thierry Reding]

[-- Attachment #1.1: Type: text/plain, Size: 761 bytes --]

On Fri, Jun 29, 2012 at 03:37:54PM -0700, H. Peter Anvin wrote:
> On 05/31/2012 08:41 AM, Thierry Reding wrote:
> > This patch series adds support for passing a Flattened Device Tree (FDT)
> > blob to the Linux kernel. Currently, only the linux.c32 module can do so
> > and some additional checking should be done to only pass the blob if the
> > kernel supports boot protocol 2.09 or later.
> > 
> > Thierry
> 
> Hi there,
> 
> I just merged a modified/more generic version of your patch.  I would
> appreciate it if you could test it and report back.

Tested latest master (59b77fc) and booted the system successfully. Can
this still make it into the 5.00 release? Any chance of getting this
directly supported by the ldlinux.sys?

Thierry

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Re: [syslinux] [RFC 0/2] syslinux: Add device tree support

[H. Peter Anvin]

It should be in linux.c32 in 4.06 and directly supported in 5.00.

Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org> wrote:

>On Fri, Jun 29, 2012 at 03:37:54PM -0700, H. Peter Anvin wrote:
>> On 05/31/2012 08:41 AM, Thierry Reding wrote:
>> > This patch series adds support for passing a Flattened Device Tree
>(FDT)
>> > blob to the Linux kernel. Currently, only the linux.c32 module can
>do so
>> > and some additional checking should be done to only pass the blob
>if the
>> > kernel supports boot protocol 2.09 or later.
>> > 
>> > Thierry
>> 
>> Hi there,
>> 
>> I just merged a modified/more generic version of your patch.  I would
>> appreciate it if you could test it and report back.
>
>Tested latest master (59b77fc) and booted the system successfully. Can
>this still make it into the 5.00 release? Any chance of getting this
>directly supported by the ldlinux.sys?
>
>Thierry

-- 
Sent from my mobile phone. Please excuse brevity and lack of formatting.