patch_user_mem_clear.c File Reference

#include <tamtypes.h>
#include <kernel.h>

Include dependency graph for patch_user_mem_clear.c:

Go to the source code of this file.

Functions
int	sbv_patch_user_mem_clear (void *start)

Detailed Description

Patch user memory clear on EE restart.

Definition in file patch_user_mem_clear.c.

Function Documentation

sbv_patch_user_mem_clear()

int sbv_patch_user_mem_clear

(

void *

start

)

@start address above which all user memory is cleared

Returns

0: success, -1: error

LoadExecPS2() wipes all user-space memory above 0x82000. With this patch, you can define a different start address to prevent your data from being overwritten. In order to completely disable the memory clear, simply pass 0x02000000 to it.

Definition at line 9 of file patch_user_mem_clear.c.

{
        int ret = -1;
        u32 *p;
 
        DI();
        ee_kmode_enter();
 
        for (p = (unsigned int*)0x80001000; p < (unsigned int*)0x80080000; p++) {
                /*
                 * Search for function call and patch $a0
                 *  lui  $a0, 0x0008
                 *  jal  InitializeUserMemory
                 *  ori  $a0, $a0, 0x2000
                 */
                if (p[0] == 0x3c040008 && (p[1] & 0xfc000000) == 0x0c000000 && p[2] == 0x34842000) {
                        p[0] = 0x3c040000 | ((unsigned int)start >> 16);
                        p[2] = 0x34840000 | ((unsigned int)start & 0xffff);
                        ret = 0;
                        break;
                }
        }
 
        ee_kmode_exit();
        EI();
 
        return ret;
}

References DI, ee_kmode_enter(), ee_kmode_exit(), and EI.