Access ptr8 from viper inside user C module?

[GanerCodes]

Hi, I'm working on improving the speed of some functions and have a mix of viper code and C code in my project. Long story short I'm not sure how to access a ptr8 from my C module, when I try and edit values it doesn't seem to change.

in my viper function we have
perform_test(buf) where buf:ptr8

and perform_test is in a c module and it simply

uint8_t *buf = (uint8_t*)(args[0]);
buf[0] = 1;

And the buf remains unchanged.

[bikeNomad]

I would expect that buf would be passed in the same way that Micropython passes integers. So in your C code you will have to extract the integer and cast it to a pointer first. The way to do this is using the macros in py/obj.h:

#include "py/runtime.h"

static mp_obj_t perform_test(mp_obj_t buf_obj) {
    uint8_t *buf = (uint8_t*)(mp_obj_get_uint(buf_obj);
    buf[0] = 1;
    return mp_const_none;
}

[GanerCodes]

Just tried this, but firmware won't boot with it like that :/

[GanerCodes]

WAIT the firmware was totally messed up cuz i had my wrong method still in there as well and the byte alignment made it break the bin, this actually worked tysm!!

[GitHubsSilverBullet]

There's a bit more to look for.
This is – I believe – the appropriate method to get access to the address.

STATIC mp_obj_t someclass_staticmethod1(mp_obj_t var1) {
    if (mp_obj_is_obj(var1)) {
        if (mp_obj_is_type(var1, &mp_type_bytearray)) {
            mp_buffer_info_t bufinfo;
            if (mp_get_buffer(var1, &bufinfo, 0)) {
                uint8_t * address8 = bufinfo.buf;
                uint32_t len = bufinfo.len;
                printf("  is bytearray @%p size=%d\n", address8, (int)len);
            }
        }
    }
    return mp_const_none;
}

[GanerCodes]

tried this and micropython wouldnt start. this is as far as i can get w/o it crashing. It doesn't print yes1

STATIC mp_obj_t perform_test(size_t n_args, const mp_obj_t *args) {
    mp_obj_t var1 = args[0];
    if(mp_obj_is_obj(var1)) {
        printf("yes1");
        // if(mp_obj_is_type(var1, &mp_type_bytearray)) {
        //     printf("yes2");
        //     mp_buffer_info_t bufinfo;
        //     if(mp_get_buffer(var1, &bufinfo, 0)) {
        //         uint8_t* address8 = bufinfo.buf;
        //         uint32_t len = bufinfo.len;
        //         printf("  is bytearray @%p size=%d\n", address8, (int)len);
        //     }
        // }
    }
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(perform_test_obj, 1, 1, perform_test);