* Modify bootm command to support booting with flat device trees

  Patch by Matthew McClintock 26-June-2006

diff --git a/README b/README
index 5ed30f27c9810c5952fd7f0af9565ba0cca4b74f..0fda03f3c27c758080516ec1924906e3a2dbf472 100644 (file)
--- a/README
+++ b/README
@@ -447,6 +447,11 @@ The following options need to be configured:
                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 @@ format!) to the "bootm" command:
 
        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 fdf7180a19a87d4974b3b1a4cc131dba4ba432ba..a472a1d7b2597fca61b1b14a945cec7cc84c0ead 100644 (file)
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -465,6 +465,13 @@ U_BOOT_CMD(
        "[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 @@ fixup_silent_linux ()
 }
 #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 @@ do_bootm_linux (cmd_tbl_t *cmdtp, int flag,
        /*
         * 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 @@ do_bootm_linux (cmd_tbl_t *cmdtp, int flag,
                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 @@ do_bootm_linux (cmd_tbl_t *cmdtp, int flag,
                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);