[OpenBIOS] [Qemu-devel] Re: QEMU OpenBIOS booting?

[malc]

On Sun, 19 Apr 2009, Steven Noonan wrote:

> On Sun, Apr 19, 2009 at 3:28 PM, Steven Noonan <steven at uplinklabs.net> wrote:
> > On Sun, Apr 19, 2009 at 2:32 PM, Steven Noonan <steven at uplinklabs.net> wrote:
> >> On Sun, Apr 19, 2009 at 2:02 PM, Steven Noonan <steven at uplinklabs.net> wrote:
> >>> On Sun, Apr 19, 2009 at 1:48 PM, Laurent Vivier <Laurent at vivier.eu> wrote:
> >>>> Le dimanche 19 avril 2009 ? 13:33 -0700, Steven Noonan a ?crit :
> >>>>> On Sun, Apr 19, 2009 at 1:24 PM, Laurent Vivier <Laurent at vivier.eu> wrote:
> >>>>> > Le dimanche 19 avril 2009 ? 13:14 -0700, Steven Noonan a ?crit :
> >>>>> > The problem is in OpenBios: I put some structures in memory without
> >>>>> > knowing this... but this is not part of openfirmware specification.

[..snip..]

> >>
> >>        diff --git a/arch/ppc/qemu/ldscript b/arch/ppc/qemu/ldscript
> >>        index 66fcbcd..8fdf654 100644
> >>        --- a/arch/ppc/qemu/ldscript
> >>        +++ b/arch/ppc/qemu/ldscript
> >>        @@ -3,15 +3,15 @@ OUTPUT_ARCH(powerpc)
> >>
> >>         /* Initial load address
> >>          */
> >>        -BASE_ADDR = 0xfff00000;
> >>        +BASE_ADDR = 0x06800000;
> >>
> >>        -/* As NVRAM is at 0xfff04000, the .text needs to be after that
> >>        +/* As NVRAM is at 0x06804000, the .text needs to be after that
> >>          */
> >>        -TEXT_ADDR = 0xfff08000;
> >>        +TEXT_ADDR = 0x06808000;
> >>
> >>         /* Hard reset vector address
> >>          */
> >>        -HRESET_ADDR = 0xfffffffc;
> >>        +HRESET_ADDR = 0x06ffffff;
> >>
> >>         CSTACK_SIZE = 32768;   /* client stack size */
> >
> > With the above numbers, I get linker problems:
> >
> > target/arch/ppc/qemu/start.o: In function `vector__0x300':
> > (.text.vectors+0x384): relocation truncated to fit: R_PPC_ADDR24
> > against `.text.vectors'+c
> > target/arch/ppc/qemu/start.o: In function `vector__0x400':
> > (.text.vectors+0x484): relocation truncated to fit: R_PPC_ADDR24
> > against `.text.vectors'+c
> >
> > I don't see why it'd do that.
> >
> 
> 
> What the hell? Why would this change resolve it?
> 
> 	diff --git a/arch/ppc/qemu/start.S b/arch/ppc/qemu/start.S
> 	index 66df9a2..108fd9b 100644
> 	--- a/arch/ppc/qemu/start.S
> 	+++ b/arch/ppc/qemu/start.S
> 	@@ -206,7 +206,7 @@ VECTOR( 0x300, "DSI" ):
> 	        addi    r3,r3,LO(dsi_exception)
> 	        mtctr   r3
> 	        bctrl
> 	-       ba      exception_return
> 	+       b       exception_return
> 	

Because exception_return's address (now near 0x06808000) doesn't fit
into 26 bit sign extended AA field.

> 	 VECTOR( 0x400, "ISI" ):
> 	        EXCEPTION_PREAMBLE
> 	@@ -214,7 +214,7 @@ VECTOR( 0x400, "ISI" ):
> 	        addi    r3,r3,LO(isi_exception)
> 	        mtctr   r3
> 	        bctrl
> 	-       ba      exception_return
> 	+       b       exception_return
> 	
> 	        ILLEGAL_VECTOR( 0x500 )
> 	        ILLEGAL_VECTOR( 0x600 )
> 
> 
> >>
> >> The only issue with doing things this way is now to figure out what to
> >> change this to:
> >>
> >> #define FREE_BASE               0x00004000
> >>
> >> My first thought was to utilize all 8MB of the space that Apple says
> >> we can have, and use any space after the OpenBIOS image. My second
> >> thought was: how do we know where the OpenBIOS executable image ends?
> >>
> >> Any ideas?
> >>
> >
> 
> 

-- 
mailto:av1474 at comtv.ru