* Modify bootm command to support booting with flat device trees Patch by Matthew McClintock 26-June-2006
diff --git a/README b/README
index 5ed30f2..0fda03f 100644
--- a/README
+++ b/README
@@ -447,6 +447,11 @@
Board code has addition modification that it wants to make
to the flat device tree before handing it off to the kernel
+ CONFIG_OF_BOOT_CPU
+
+ This define fills in the correct boot cpu in the boot
+ param header, the default value is zero if undefined.
+
- Serial Ports:
CFG_PL010_SERIAL
@@ -3013,6 +3018,55 @@
bash#
+Boot Linux and pass a flat device tree:
+-----------
+
+First, U-Boot must be compiled with the appropriate defines. See the section
+titled "Linux Kernel Interface" above for a more in depth explanation. The
+following is an example of how to start a kernel and pass an updated
+flat device tree:
+
+=> print oftaddr
+oftaddr=0x300000
+=> print oft
+oft=oftrees/mpc8540ads.dtb
+=> tftp $oftaddr $oft
+Speed: 1000, full duplex
+Using TSEC0 device
+TFTP from server 192.168.1.1; our IP address is 192.168.1.101
+Filename 'oftrees/mpc8540ads.dtb'.
+Load address: 0x300000
+Loading: #
+done
+Bytes transferred = 4106 (100a hex)
+=> tftp $loadaddr $bootfile
+Speed: 1000, full duplex
+Using TSEC0 device
+TFTP from server 192.168.1.1; our IP address is 192.168.1.2
+Filename 'uImage'.
+Load address: 0x200000
+Loading:############
+done
+Bytes transferred = 1029407 (fb51f hex)
+=> print loadaddr
+loadaddr=200000
+=> print oftaddr
+oftaddr=0x300000
+=> bootm $loadaddr - $oftaddr
+## Booting image at 00200000 ...
+ Image Name: Linux-2.6.17-dirty
+ Image Type: PowerPC Linux Kernel Image (gzip compressed)
+ Data Size: 1029343 Bytes = 1005.2 kB
+ Load Address: 00000000
+ Entry Point: 00000000
+ Verifying Checksum ... OK
+ Uncompressing Kernel Image ... OK
+Booting using flat device tree at 0x300000
+Using MPC85xx ADS machine description
+Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
+[snip]
+
+
More About U-Boot Image Types:
------------------------------
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index fdf7180..a472a1d 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -465,6 +465,13 @@
"[addr [arg ...]]\n - boot application image stored in memory\n"
"\tpassing arguments 'arg ...'; when booting a Linux kernel,\n"
"\t'arg' can be the address of an initrd image\n"
+#ifdef CONFIG_OF_FLAT_TREE
+ "\tWhen booting a Linux kernel which requires a flat device-tree\n"
+ "\ta third argument is required which is the address of the of the\n"
+ "\tdevice-tree blob. To boot that kernel without an initrd image,\n"
+ "\tuse a '-' for the second argument. If you do not pass a third\n"
+ "\ta bd_info struct will be passed instead\n"
+#endif
);
#ifdef CONFIG_SILENT_CONSOLE
@@ -500,11 +507,6 @@
}
#endif /* CONFIG_SILENT_CONSOLE */
-#ifdef CONFIG_OF_FLAT_TREE
-extern const unsigned char oftree_dtb[];
-extern const unsigned int oftree_dtb_len;
-#endif
-
#ifdef CONFIG_PPC
static void
do_bootm_linux (cmd_tbl_t *cmdtp, int flag,
@@ -616,7 +618,17 @@
/*
* Check if there is an initrd image
*/
+
+#ifdef CONFIG_OF_FLAT_TREE
+ /* Look for a '-' which indicates to ignore the ramdisk argument */
+ if (argc >= 3 && strcmp(argv[2], "-") == 0) {
+ debug ("Skipping initrd\n");
+ data = 0;
+ }
+ else
+#endif
if (argc >= 3) {
+ debug ("Not skipping initrd\n");
SHOW_BOOT_PROGRESS (9);
addr = simple_strtoul(argv[2], NULL, 16);
@@ -724,6 +736,15 @@
len = data = 0;
}
+#ifdef CONFIG_OF_FLAT_TREE
+ if (argc >= 3)
+ {
+ of_flat_tree = (char *) simple_strtoul(argv[3], NULL, 16);
+ printf ("Booting using flat device tree at 0x%x\n",
+ of_flat_tree);
+ }
+#endif
+
if (!data) {
debug ("No initrd\n");
}
@@ -793,15 +814,6 @@
initrd_end = 0;
}
-#ifdef CONFIG_OF_FLAT_TREE
- if (initrd_start == 0)
- of_flat_tree = (char *)(((ulong)kbd - OF_FLAT_TREE_MAX_SIZE -
- sizeof(bd_t)) & ~0xF);
- else
- of_flat_tree = (char *)((initrd_start - OF_FLAT_TREE_MAX_SIZE -
- sizeof(bd_t)) & ~0xF);
-#endif
-
debug ("## Transferring control to Linux (at address %08lx) ...\n",
(ulong)kernel);