Re: Regarding virtual to physical memory mapping..
Hi all, Sorry for replying late.. and thanks everyone for replying. i am not clear with answers that are given to the question . I have written a function in assembly that i have called form C code and done the linking correctly. But i want this code should run in real mode. The address that i am getting for the function is 0x5e45c000 which is a virtual address so i need to get its actual physical address to execute it in real mode (which should be less than 1 MB). So i wanted to ask is there any way to do mapping from virtual to physical in grub? Also is there any way by which i can have that assembly function placed below 1 MB ? Best regards, Kiran Pawar. ___ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
Re: Regarding virtual to physical memory mapping..
On Thu, Dec 31, 2009 at 01:31:05PM +0100, Vladimir 'φ-coder/phcoder' Serbinenko wrote: > > I wanted to know whether I can allocate some > > memory in the region below 1MB? > Only in experimental branch. But we're not currently sure if we will use > this. We can use this. My concerns are with making intrusive changes in the standard heap. I think it's important that kern/mm.c is small and simple, but this doesn't preclude doing more fancy stuff in non-core areas. Sorry if I was unclear about it. -- Robert Millan "Be the change you want to see in the world" -- Gandhi ___ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
Re: Regarding virtual to physical memory mapping..
El jue, 31-12-2009 a las 13:31 +0100, Vladimir 'φ-coder/phcoder' Serbinenko escribió: > kiran pawar wrote: > > Also, when I allocated memory using grub_malloc() and printed the > > address returned from the function it was (0x7da6d810). This seems to > > be a 32-bit address. I wanted to know whether I can allocate some > > memory in the region below 1MB? > Only in experimental branch. But we're not currently sure if we will use > this. If you want to make a BIOS call then use memory at > GRUB_SCRATCH_ADDR. If you do something else please explain How come not? Here's how it's done in drivemap, for example handler_base = grub_mmap_malign_and_register (16, total_size, &drivemap_mmap, GRUB_MACHINE_MEMORY_RESERVED, GRUB_MMAP_MALLOC_LOW); -- -- Lazy, Oblivious, Recurrent Disaster -- Habbit signature.asc Description: Esta parte del mensaje está firmada digitalmente ___ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
Re: Regarding virtual to physical memory mapping..
kiran pawar wrote: > Hi all, > I am working on grub-1.97.1. I wanted to know if there is any > mechanism in grub2 that maps virtual addresses to physical addresses > below 1 MB? > When I checked the code for grub-0.97, I found that there are > function as below >#define phys_to_virt(x) (x) >#define virt_to_phys(x) (x) > grub runs without paging enabled. So such function is identity on x86. > Are there any similar functions in grub-1.97.1? > > Also, when I allocated memory using grub_malloc() and printed the > address returned from the function it was (0x7da6d810). This seems to > be a 32-bit address. I wanted to know whether I can allocate some > memory in the region below 1MB? Only in experimental branch. But we're not currently sure if we will use this. If you want to make a BIOS call then use memory at GRUB_SCRATCH_ADDR. If you do something else please explain > > Regards, > Kiran Pawar. > > > ___ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel > -- Regards Vladimir 'φ-coder/phcoder' Serbinenko signature.asc Description: OpenPGP digital signature ___ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
Regarding virtual to physical memory mapping..
Hi all, I am working on grub-1.97.1. I wanted to know if there is any mechanism in grub2 that maps virtual addresses to physical addresses below 1 MB? When I checked the code for grub-0.97, I found that there are function as below #define phys_to_virt(x) (x) #define virt_to_phys(x) (x) Are there any similar functions in grub-1.97.1? Also, when I allocated memory using grub_malloc() and printed the address returned from the function it was (0x7da6d810). This seems to be a 32-bit address. I wanted to know whether I can allocate some memory in the region below 1MB? Regards, Kiran Pawar. ___ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
