Re: [U-Boot] Is it necessary that uboot(mips) should read status register($12) before setting it
On 09/28/2011 06:09 PM, RdrouterUboot Router wrote: 2.Is it right?I can delete this code mfc0 $10,$12 from uboot. You can delete that MFC0 instruction in this case and save one word. Presumably the original code used to update the Status register value in read-modify-write manner, and at some point someone modified into current shape. By the way, since the first MIPS implementation of U-Boot was merged into the tree (by wdenk), we've been using k0($26) or t0($8) register as a scratch pad when modifying the Status register, while your example code uses t2($10). So it would be a custom U-Boot we don't know of. ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] Is it necessary that uboot(mips) should read status register($12) before setting it
Hi Bruce, MIPS Uboot works OK.Part of the code is as below. Congratulations. Although I'm not sure what I'm congratulating on ;) And my questions: 1.read status register($12) and save value to $10,but don't use the value in $10 to do anything. Because uboot overwrite $10. 2.Is it right?I can delete this code mfc0 $10,$12 from uboot. I'm sorry, but I don;t know what to make of this. Can you tell us if this code is from U-Boot and if so, in which file? Also can't you try for yourself if U-Boot still works after removing this instruction? What exactly do you want us to tell you? Cheers Detlev -- If I could ask a genie to grant me one wish for free software, it would not be about the popularity of the GNU Hurd, or even the popularity of the GNU system. I would wish for all software users to have reedom and value free- dom. -- Richard Stallman e1oipab-00016e...@fencepost.gnu.org -- DENX Software Engineering GmbH, MD: Wolfgang Denk Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: d...@denx.de ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] Is it necessary that uboot(mips) should read status register($12) before setting it
On Wednesday, September 28, 2011 11:09:05 AM RdrouterUboot Router wrote: Hi all, MIPS Uboot works OK.Part of the code is as below. And my questions: 1.read status register($12) and save value to $10,but don't use the value in $10 to do anything. Because uboot overwrite $10. 2.Is it right?I can delete this code mfc0 $10,$12 from uboot. Thanks. Bruce I don't see this code in uboot at all ... what version do you use ? ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
[U-Boot] Is it necessary that uboot(mips) should read status register($12) before setting it
Hi all, MIPS Uboot works OK.Part of the code is as below. And my questions: 1.read status register($12) and save value to $10,but don't use the value in $10 to do anything. Because uboot overwrite $10. 2.Is it right?I can delete this code mfc0 $10,$12 from uboot. Thanks. Bruce # Initialize Misc. Cop0 state # Read status register mfc0$10, $12 //Can I delete this code? # Set up Status register: # Disable Coprocessor Usable bits # Turn off Reduce Power bit # Turn off reverse endian # Turn off BEV (use normal exception vectors) # Clear TS, SR, NMI bits # Clear Interrupt masks # Clear User Mode # Clear ERL # Set EXL # Clear Interrupt Enable # modify by Bruce #li$11, 0xff02 li$11, 0x0004 mtc0$11, $12 # Disable watch exceptions mtc0$0, $18 # Clear Watch Status bits li$11, 0x3 mtc0$11, $19 # Clear WP bit to avoid watch exception upon user code entry # Clear IV bit - Interrupts go to general exception vector # Clear software interrupts mtc0$0, $13 # Set KSeg0 to cacheable # Config.K0 mfc0$10, $16//Overwrite $10 register.Why uboot read status register($12) and save value to $10,but don't use $10. li$11, 0x7 not$11 and$10, $11 or$10, 0x3 mtc0$10, $16 ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
