Talk:Forth Lesson 9: Difference between revisions

From OLPC
Jump to navigation Jump to search
(Location and Execution of OFW)
 
m (→‎Location and Execution of OFW: Link to Lesson 20 and hardware testing.)
 
(2 intermediate revisions by 2 users not shown)
Line 2: Line 2:


OFW is stored in the 1024 KiB SPI-interface flash ROM and executes in the CPU; correct? No doubt obvious to some. The additional information would be helpful to me and others with limited background. Thanks, [[User:Peasthope|Peasthope]] 22:11, 23 October 2012 (UTC)
OFW is stored in the 1024 KiB SPI-interface flash ROM and executes in the CPU; correct? No doubt obvious to some. The additional information would be helpful to me and others with limited background. Thanks, [[User:Peasthope|Peasthope]] 22:11, 23 October 2012 (UTC)
:No, not obvious, but not relevant for Lesson 9. See [[Forth_Lesson_20]]. Summary: copies of Open Firmware are in the SPI FLASH and the internal storage as /boot/bootfw.zip, but it is the copy in SPI FLASH that is used first on power-up. On XO-1.75 and XO-4, it is copied to RAM and the CPU executes it from RAM. --[[User:Quozl|Quozl]] 22:30, 23 October 2012 (UTC)

OK, thanks. I've added a link to Lesson 20 in case anyone else has a simialr interest. No offense if you revert or change it. [[User:Peasthope|Peasthope]] 19:06, 31 October 2012 (UTC)

By the way, you separated the link from hardware testing because Lesson 20 doesn't discuss it; correct? Presumeably OFW tests hardware as does the PC BIOS, ... [[User:Peasthope|Peasthope]] 18:20, 2 November 2012 (UTC)

Latest revision as of 18:20, 2 November 2012

Location and Execution of OFW

OFW is stored in the 1024 KiB SPI-interface flash ROM and executes in the CPU; correct? No doubt obvious to some. The additional information would be helpful to me and others with limited background. Thanks, Peasthope 22:11, 23 October 2012 (UTC)

No, not obvious, but not relevant for Lesson 9. See Forth_Lesson_20. Summary: copies of Open Firmware are in the SPI FLASH and the internal storage as /boot/bootfw.zip, but it is the copy in SPI FLASH that is used first on power-up. On XO-1.75 and XO-4, it is copied to RAM and the CPU executes it from RAM. --Quozl 22:30, 23 October 2012 (UTC)

OK, thanks. I've added a link to Lesson 20 in case anyone else has a simialr interest. No offense if you revert or change it. Peasthope 19:06, 31 October 2012 (UTC)

By the way, you separated the link from hardware testing because Lesson 20 doesn't discuss it; correct? Presumeably OFW tests hardware as does the PC BIOS, ... Peasthope 18:20, 2 November 2012 (UTC)