Load plugins in usermode lv2 module_start

[illusionyy]

For 4.84 REX and 4.92 PEX only, can be easily ported to other fws.
will look for /dev_hdd0/game_plugin_bootloader.sprx and start it. if you have exceptions enabled in shellcode, you'll get exceptions to find out any errors.

[illusionyy]

Updated to be able to modify argc/argv.

Code (Click to expand)

#if defined(__PRX__)
typedef union bigint
{
    struct _c
    {
        char* hi;
        char* lo;
    } c;
} bigint;
#define pChar bigint
#define pChar2 bigint*
#else
#define pChar uint64_t
#define pChar2 uint32_t
#endif

typedef struct program_args
{
    uint32_t argc;
    pChar2 argv;
    uint32_t replace_args_size;
    uint32_t replace_args_per_buf_size;
    pChar new_argv[max_args];
    char replace_args[max_args][max_arg_buf + 1];
    struct change_flag
    {
        uint64_t changed : 1;
    } flag;
} program_args;
#if defined(__cplusplus)
static_assert(__builtin_offsetof(program_args, argc) == 0, "");
static_assert(__builtin_offsetof(program_args, argv) == 4, "");
static_assert(__builtin_offsetof(program_args, replace_args_size) == 8, "");
static_assert(__builtin_offsetof(program_args, replace_args_per_buf_size) == 12, "");
static_assert(__builtin_offsetof(program_args, new_argv) == 16, "");
static_assert(__builtin_offsetof(program_args, replace_args) == 272, "");
#endif

extern "C" int module_start(unsigned int argc, program_args& arg)
{
    printf("program_args size %d\n", sizeof(program_args));
    printf("arg %p argc %d argv %p\n", &arg, arg.argc, arg.argv);
    printf("replace_arg_buf %ld\n", arg.replace_args_size);
    for (uint32_t i = 0; i < arg.argc; i++)
    {
        printf("arg[%d]: (%p) %s\n", i, &arg.argv[i].c.lo, arg.argv[i].c.lo ? arg.argv[i].c.lo : "");
    }
#if defined(enable_arg_modify)
    size_t diff_bytes = 0;
    if (!check_bytes(arg.replace_args, 0, arg.replace_args_size, diff_bytes))
    {
        printf("WARNING: replacement arg buf contains %ld bytes that was not zero! was the stack ever truly cleared?\n", diff_bytes);
    }
    else
    {
        printf("checked replacement buf of %ld bytes and it was all clear!\n", arg.replace_args_size);
    }
#endif

#if defined(enable_arg_modify)
    bool no_copy = false;
    if (!copy_main_args(&arg, arg.argc, arg.argv))
    {
        printf("failed to copy main argc/argv\n");
        no_copy = true;
    }
    if (!no_copy)
    {
        append_arg(&arg, "-novsync");
    }
    printf("argc now %d\n", arg.argc);
    for (uint32_t i = 0; i < arg.argc; i++)
    {
        printf("arg[%d]: (%p) %s\n", i, arg.new_argv[i].c.lo, arg.new_argv[i].c.lo ? arg.new_argv[i].c.lo : "");
    }
#endif

    sys_timer_sleep(5);
    return SYS_PRX_NO_RESIDENT;
}

Output (Click to expand)

program_args size 9656
arg 0xd003e830 argc 1 argv 0xd0040fb0
replace_arg_buf 9376
arg[0]: (0xd0040fb4) /dev_hdd0/game/NPUB90119/USRDIR/EBOOT.BIN
checked replacement buf of 9376 bytes and it was all clear!

pargs->replace_args[1]: -novsync
argc now 2
arg[0]: (0xd0040fd0) /dev_hdd0/game/NPUB90119/USRDIR/EBOOT.BIN
arg[1]: (0xd003ea65) -novsync
# In main()
Commandline init...
CommandLine: -novsync 

[illusionyy]

Ported to 4.92 PEX. Checked CEX and DEX kernels and they seem to work.

*** network ready. myaddr: 192.168.1.26 ***
===== Start agent =====
Debug Agent Version: 4.9.2 (62)
Mini Debug Agent Version 4.9.2 (62) (Built - Mar  5 2025 12:00:00)
...
Game: game exec processID = [0x01010200]
Load module: /dev_flash/sys/external/libsysmodule.sprx (_main_EBOOT.BIN)
passed check
lv2 base 0x1e50000 0x1e63b68
lv2 read 39c00000 check 39c00000 ret 0
lv2 base 1e50000 size 13b68 (max 1e63b68)
code size 204 seeked 1e63960
Load module: /dev_hdd0/game_plugin_bootloader.sprx (_main_EBOOT.BIN)

[illusionyy]

@Evilnat ready for merge.

[Evilnat]

Could you explain a little about what I could do with your new changes? Thanks in advance

[illusionyy]

Could you explain a little about what I could do with your new changes? Thanks in advance

@Evilnat it can load plugins on app startup. Previously you'd have to patch game executable manually, resign it correctly for CEX or DEX and it was just a mess.

Now it's just as simple as putting a plugin somewhere, adding it to /dev_hdd0/game_plugins.yml and shellcode in liblv2 from this PR and bootloader plugin will take care of the rest.

Also this shellcode also sets up a struct for argc/argv to be edited by plugins, so users may add their own cmdline before start() in executable is executed.

[LuanTeles]

Could you explain a little about what I could do with your new changes? Thanks in advance

@Evilnat it can load plugins on app startup. Previously you'd have to patch game executable manually, resign it correctly for CEX or DEX and it was just a mess.

Now it's just as simple as putting a plugin somewhere, adding it to /dev_hdd0/game_plugins.yml and shellcode in liblv2 from this PR and bootloader plugin will take care of the rest.

Also this shellcode also sets up a struct for argc/argv to be edited by plugins, so users may add their own cmdline before start() in executable is executed.

That's a much needed feature :)

[Evilnat]

Could you explain a little about what I could do with your new changes? Thanks in advance

@Evilnat it can load plugins on app startup. Previously you'd have to patch game executable manually, resign it correctly for CEX or DEX and it was just a mess.

Now it's just as simple as putting a plugin somewhere, adding it to /dev_hdd0/game_plugins.yml and shellcode in liblv2 from this PR and bootloader plugin will take care of the rest.

Also this shellcode also sets up a struct for argc/argv to be edited by plugins, so users may add their own cmdline before start() in executable is executed.

Thanks mate!

I need to check that the final size of stage2 doesn't exceed the maximum allowed, although I also want to increase it to avoid problems. Give me a few days so I can check and test it.

Thank you very much for your contribution

[illusionyy]

Even in debug, it doesn't exceed 127k for me in PEX build. In release it's about 110k I believe so it should be okay.