Re: Cannot Access Memory

[BALATON Zoltan]

On Wed, 6 Oct 2021, Jesse Millwood wrote:
> I broke on "booke206_initial_map_tsize" and found the "dt_end" to be set to 
> 0x0190_0000, which is far smaller than the u-boot elf entry point.
>
> I tried this hack to see if I could access memory:
> static int booke206_initial_map_tsize(CPUPPCState *env)
> {
> -    struct boot_info *bi = env->load_info;
> -    hwaddr dt_end;
>     int ps;
>
>     /* Our initial TLB entry needs to cover everything from 0 to
>        the device tree top */
> -    dt_end = bi->dt_base + bi->dt_size;
> -    ps = booke206_page_size_to_tlb(dt_end) + 1;
> +    ps = booke206_page_size_to_tlb(0xfff80000) + 1;

This should be end of the u-boot image not the start, this probably only 
maps the first page so it will crash after running off that. Previously 
you wrote:

(qemu) info roms
addr=0000000000000020 size=0x018090 mem=ram name="./srcs/u-boot-vendor/u-boot ELF 
program header segment 1"
addr=00000000fff80000 size=0x080000 mem=ram name="./srcs/u-boot-vendor/u-boot ELF 
program header segment 0"

so this mapping should be up to 0xfff80000 + 0x80000 i.e. up to 0x100000000.

Regards,
BALATON Zoltan