DON'T MERGE: this is only a concept patch.
On some device, barebox is the second bootloader. The first bootloader provide
some times allready a better device tree as the linux kernel own.
Mostly barebox can't boot from this device tree but the linux kernel can.
This patch allow to load a device tree from memory from first bootloader.
For implementation:
Not sure what is the best. Maybe we can create a of_unflatten_file_dtb() and
of_unflatten_memory_dtb() they return fdt. There are a lot place they load
a fdt from a file and repeat the same code.
Signed-off-by: Pascal Vizeli <pvizeli@xxxxxxxxxx>
---
commands/oftree.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/commands/oftree.c b/commands/oftree.c
index 8a47c0be5..831b6c280 100644
--- a/commands/oftree.c
+++ b/commands/oftree.c
@@ -40,9 +40,40 @@
#include <fcntl.h>
#include <complete.h>
+struct fdt_header* read_memory_dtb(loff_t mem_start)
+{
+ struct fdt_header *oftree = NULL;
+ struct fdt_header *memtree;
+ int mode = O_RWSIZE_4 | O_RDONLY;
+ int fd;
+ uint32_t size;
+ void *map;
+
+ fd = open_and_lseek("/dev/mem", mode,mem_start);
+ if (fd < 0)
+ return NULL;
+
+ map = memmap(fd, PROT_READ);
+ if (map == (void *)-1)
+ goto end;
+ memtree = map;
+
+ size = be32_to_cpu(memtree->totalsize);
+ if (!size)
+ goto end;
+
+ oftree = malloc(size);
+ memcpy((void *)oftree, map, size);
+
+end:
+ close(fd);
+ return oftree;
+}
+
static int do_oftree(int argc, char *argv[])
{
struct fdt_header *fdt = NULL;
+ loff_t mem_start;
size_t size;
int opt;
int probe = 0;
@@ -102,7 +133,13 @@ static int do_oftree(int argc, char *argv[])
}
if (load) {
- fdt = read_file(load, &size);
+ if (file_name_detect_type(load) == filetype_oftree) {
+ fdt = read_file(load, &size);
+ } else {
+ mem_start = simple_strtoull(load, NULL, 0);
+ fdt = read_memory_dtb(mem_start);
+ }
+
if (!fdt) {
printf("unable to read %s\n", load);
return 1;
--
2.17.1
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