page size change on MIPS
From: David Daney <hidden>
Date: 2011-01-28 18:48:58
Also in:
linux-mips
Possibly related (same subject, not in this thread)
- 2011-02-08 · page size change on MIPS · Mulyadi Santosa <hidden>
- 2011-02-05 · page size change on MIPS · Mulyadi Santosa <hidden>
- 2011-02-04 · page size change on MIPS · David Daney <hidden>
- 2011-02-04 · page size change on MIPS · naveen yadav <hidden>
- 2011-02-04 · page size change on MIPS · naveen yadav <hidden>
On 01/28/2011 01:18 AM, naveen yadav wrote:
Hi all I try changing the kernel_execve() function as suggested, but it fails, I am using code sourcery toolchain 4.4.1 but it still fails. I am using 2.6.30.9 kernel and this function is part of it.
Quit trying to change kernel_execve(). It is perfect as it is. The problem is elsewhere.
Kind regards
Thank you.
On Thu, Jan 27, 2011 at 11:14 PM, David Daney[off-list ref] wrote:quoted
On 01/27/2011 07:18 AM, adnan iqbal wrote:quoted
Please try this. One line of code is added ( move %1, $7). int kernel_execve(const char *filename, char *const argv[], char *const envp[]) { register unsigned long __a0 asm("$4") = (unsigned long) filename; register unsigned long __a1 asm("$5") = (unsigned long) argv; register unsigned long __a2 asm("$6") = (unsigned long) envp; register unsigned long __a3 asm("$7"); unsigned long __v0; __asm__ volatile (" \n" " .set noreorder \n" " li $2, %5 # __NR_execve \n" " syscall \n" " move %0, $2 \n" " move %1, $7 \n" " .set reorder \n" : "=&r" (__v0), "=r" (__a3) : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve) : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", "memory"); if (__a3 == 0) return __v0; return -__v0; }I don't know where you got that code. But really you should do what glibc does. glibc gets it correct. At a minimum you are missing "hi" and "lo" clobbers.
Ignore that ^^^^^ advice.
quoted
If the code works with 16K pages, and not 64K pages, then this snippet is not the problem. Likely your problem is the layout of the PHDRs in the executable is not compatible with the page size.
Instead look at this issue.
quoted
David Daneyquoted
On Thu, Jan 27, 2011 at 7:55 PM, naveen yadav[off-list ref] wrote:quoted
Hi David, thanks for your response. I check and found that kernel is booting with 16KB page size with ramdisk booting. But when I change to 64KB it give me : applet not found Kernel panic - not syncing: Attempted to kill init! so I check and found that it is not able to execute well the system call in kernel_execve function. I am using codesourcercy toolchain(4.3.1). So is there a way to debug this problem or how to debug below function. int kernel_execve(const char *filename, char *const argv[], char *const envp[]) { register unsigned long __a0 asm("$4") = (unsigned long) filename; register unsigned long __a1 asm("$5") = (unsigned long) argv; register unsigned long __a2 asm("$6") = (unsigned long) envp; register unsigned long __a3 asm("$7"); unsigned long __v0; __asm__ volatile (" \n" " .set noreorder \n" " li $2, %5 # __NR_execve \n" " syscall \n" " move %0, $2 \n" " .set reorder \n" : "=&r" (__v0), "=r" (__a3) : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve) : "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24", "memory"); if (__a3 == 0) return __v0; return -__v0; } On Tue, Jan 25, 2011 at 12:26 AM, David Daney[off-list ref] wrote:quoted
On 01/24/2011 07:02 AM, naveen yadav wrote:quoted
Hi All, we are using mips32r2 so I want to know which all pages size it can support? When I modify arch/mips/Kconfig. it boot sucessfully on 16KB page size. but hang/not boot crash when change page size to 8KB,32KB and 64 KB.I don't think 8KB and 32KB work on most mips32r2 processors. You wouldhavequoted
to check the processor manual to be sure.quoted
We are using 2.6.30 kernel. At Page Size 8KB and 32KB it hang in unpack_to_rootfs() function of init/initramfs.c 64KB it hangs when execute init Kernel panic - not syncing: Attempted to kill init!I regularly run 4K, 16K, and 64K page sizes with a Debian rootfs. If you run with a broken uClibc toolchain that doesn't support larger pages, it will of course fail. In this case the problem is with your toolchain,notquoted
the kernel. David Daneyquoted
config PAGE_SIZE_4KB bool "4kB" help This option select the standard 4kB Linux page size. On some R3000-family processors this is the only available page size. Using 4kB page size will minimize memory consumption and is therefore recommended for low memory systems. config PAGE_SIZE_8KB bool "8kB" depends on (EXPERIMENTAL&& CPU_R8000) || CPU_CAVIUM_OCTEON help Using 8kB page size will result in higher performance kernelatquoted
quoted
the price of higher memory consumption. This option is available only on R8000 and cnMIPS processors. Note that you will needaquoted
quoted
suitable Linux distribution to support this. config PAGE_SIZE_16KB bool "16kB" depends on !CPU_R3000&& !CPU_TX39XX help Using 16kB page size will result in higher performance kernelatquoted
quoted
the price of higher memory consumption. This option is available on all non-R3000 family processors. Note that you will need a suitable Linux distribution to support this. config PAGE_SIZE_32KB bool "32kB" help Using 32kB page size will result in higher performance kernelatquoted
quoted
the price of higher memory consumption. This option is available only on cnMIPS cores. Note that you will need a suitableLinuxquoted
quoted
distribution to support this. config PAGE_SIZE_64KB bool "64kB" depends on EXPERIMENTAL&& !CPU_R3000&& !CPU_TX39XX help Using 64kB page size will result in higher performance kernelatquoted
quoted
the price of higher memory consumption. This option is available on all non-R3000 family processor. Not that at the time of this writing this option is still high experimental.