On 03/25/2014 08:13 AM, Peter Maydell wrote: > On 25 March 2014 03:34, Joel Fernandes <jo...@ti.com> wrote: >> Loading kernel at offset 0x10000 works only for zImage, but not for Image, >> because the kernel expect the start of decompressed kernel (.head.text) to be >> at an address that's a distance that's 16MB aligned from PAGE_OFFSET + >> TEXT_OFFSET (see vmlinux.lds.S). This check is enfornced in __fixup_pv_table >> in >> arch/arm/kernel/head.S TEXT_OFFSET is 0x00008000, so a 16MB alignment needs >> to >> have a "0x8000" in the lower 16 bits so that they cancel out. Currently the >> offset Qemu loads it at is 0x10000. >> >> With zImage, this need is met because zImage loads the uncompressed Image >> correctly, however when loading an Image and executing directly Qemu is >> required it to load it at the correct location. Doing so, doesn't break >> Qemu's >> zImage loading. With this patch, both zImage and Image work correctly. >> >> Signed-off-by: Joel Fernandes <jo...@ti.com> >> --- >> hw/arm/boot.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/hw/arm/boot.c b/hw/arm/boot.c >> index dc62918..566b5c2 100644 >> --- a/hw/arm/boot.c >> +++ b/hw/arm/boot.c >> @@ -23,7 +23,7 @@ >> * They have different preferred image load offsets from system RAM base. >> */ >> #define KERNEL_ARGS_ADDR 0x100 >> -#define KERNEL_LOAD_ADDR 0x00010000 >> +#define KERNEL_LOAD_ADDR 0x00008000 >> #define KERNEL64_LOAD_ADDR 0x00080000 > > The patch and rationale seem plausible, but I'm a bit > reluctant to apply this this close to 2.0 release, because > QEMU has loaded images at this address for 8 years without > anybody complaining, and I worry that we might accidentally > break some other use case somehow.
I understand. FWIW, I also tested with a15-vexpress and zImage. thanks, -Joel
