Kernel XIP - Revision history

Tim Bird: /* How to determine offsets for sections */ add to System Size category

2011-02-05T00:56:05Z

‎How to determine offsets for sections: add to System Size category

2010-06-16T23:12:58Z

add link to wikipedia entry for XIP

2008-11-15T16:26:54Z

2008-10-10T01:22:34Z

‎Case 1 - XIP on Arctic III PowerPC board

2008-10-10T01:20:48Z

‎Case 2 - XIP on OMAP Innovator

2007-09-19T16:19:31Z

‎Case 2 - XIP on OMAP Innovator: fix link to omap instructions

2007-09-19T16:07:38Z

‎Case 3 - comparing NOR XIP with OneNAND quick-copy to RAM

2007-09-19T16:03:39Z

‎Case 3 - comparing NOR XIP with OneNAND quick-copy to RAM: revert pdf link to regular link (for external document)

2007-09-19T16:01:30Z

‎How to determine offsets for sections

2007-09-19T15:57:33Z

‎Using XIP with U-Boot on Arm

@@ Line 2: / Line 2: @@
 == Description ==
 When the kernel is executed in place, the bootloader does not have to:
-#read the kernel from flash or
+# read the kernel from flash or
-#decompress the kernel and
+# decompress the kernel and
-#write the kernel to RAM.
+# write the kernel to RAM.
 == How to implement or use ==

@@ Line 84: / Line 84: @@
 |Decompress kernel
 |453 ms
-|style="background:#c0c080;"0 ms
+|style="background:#c0c080;"|0 ms
 |-
 |Kernel time to initialize<br/>(time to first user space program)

@@ Line 122: / Line 122: @@
 |56 ms
 |120 ms
-|style="background:#c0c080;"0 ms
+|style="background:#c0c080;"|0 ms
 |-
 |Decompress kernel

@@ Line 110: / Line 110: @@
 *Kernel Version: 2.4.20 (precursor to CELF tree)
 *Configuration: [need to put config information here]
-*see ["KernelXIPInstructionsForOMAP"]
+*see [[Kernel XIP Instructions For OMAP]]

@@ Line 222: / Line 222: @@
 |align="right"|1,635,540
 |align="right"|478,938
 |}

@@ Line 228: / Line 228: @@
 **[http://www.muru.com/linux/omap omap patch archive]
 **[http://www.samsung.com/Products/Semiconductor/Flash/TechnicalInfo/datasheets.htm Samsung NAND flash memory datasheet]
-**{{pdf|http://www.samsung.com/Products/Semiconductor/Support/ebrochure/memory/onenand_v10.pdf OneNAND e-brochure}}
+**[http://www.samsung.com/Products/Semiconductor/Support/ebrochure/memory/onenand_v10.pdf OneNAND e-brochure]
 == Questions ==

@@ Line 267: / Line 267: @@
 === How to determine offsets for sections ===
-<code>
+Dick Johnson talks about how to set the physical address for ELF sections by
 On Fri, 21 Oct 2005, Sreeni wrote:
 >> Hi,<br>
@@ Line 292: / Line 295: @@
 Note that "." means "right here", just like '$' in many assemblers. You can specify a physical offset simply as:
-<pre>
-ENTRY(_start)
+ ENTRY(_start)
-SECTIONS
+ SECTIONS
-−
+ {
     . == 0x01000000  <==== like this for code
     .text : {
@@ Line 304: / Line 307: @@
      .data : {  }
      .bss  : {  }
-−
+ }
-</pre>
 In the above, we have put .rodata (initialized ASCII stuff) right after the code in the .text section. You may need to extract this from the binary blob to put into your NVRAM.
 Also, any initialzed data needs to be relocated to your writable SDRAM and the .bss stuff needs to be zeroed. This is non-trivial. You may want to create a ".reloc" section which contains your initialized data, put it in your flash, and relocate it at startup.
-Basically executing-in-place is BAD. Flash should exist in some little window where the code gets sucked out, loaded at the correct offset in RAM, then you jump there and close the little window. RAM, even SDRAM,is cheaper than NAND FLASH. You can boot instantly even as I have shown.
+...
 Cheers,
 Dick Johnson
 [[Category:Boot Time]]
 [[Category:Kernel XIP]]

@@ Line 244: / Line 244: @@
 === Using XIP with U-Boot on Arm ===
 Wolfgang Denks, the primary author of the UBoot bootloader, wrote the following:
-<code>
+<pre>
 >> Yes. But... _Does_ mkimage -x put header on the front of it?
@@ Line 260: / Line 260: @@
 U-Boot expects (and verifies) that the entry point is  equal  to  the load address plus the size of the U-Boot header.
-</code>
+</pre>
 Lots more details are in the thread (split across months in the archives):