Jocelyn Mayer wrote: > On Wed, 2007-10-17 at 14:51 +0100, Thiemo Seufer wrote: > > J. Mayer wrote: > > > I failed to run Mips target test image on my amd64 machine and I now > > > found the reason of the bug: > > > the kernel loader code used in hw/mips_r4k.c and hw/mips_malta.c > > > implicitelly assumes that the ram_addr_t is 32 bits long. > > > Unfortunatelly, on 64 bits hosts, this won't be the case and the kernel > > > load address then is over 4 GB. Then, when computing the initrd_offset, > > > the code always concludes that there's not enough RAM available to load > > > it at the top of the kernel. > > > I found 2 ways of fixing the bug, but I don't know which one is correct > > > in Mips execution environment. > > > The first patch is to make the VIRT_TO_PHYS_ADDEND negative, thus > > > translating the kernel virtual address from 0x8000nnnn to the physical > > > one 0x0000nnnn (instead of 0x10000nnnn, when running on 64 bits hosts). > > > The second solution would be to explicitelly always cast the kernel_high > > > value to 32 bits. > > > As I do not really know if some Mips target specific constraints would > > > make one of the other solution prefered, I'd better let the specialist > > > choose ! > > > > > > The good news is that, once this issue is fixed, the Mips test images > > > run with the reverse-endian softmmu patch applied. > > > > I think this patch is the correct fix. Please test and comment. > > Thanks, I'll test it at home tonight. > To satisfy my curiosity, is there a specific reason to have a positive > VIRT_TO_PHYS_ADDEND ?
So it wraps around correctly WRT the sign extension rules. Thiemo
