// Environment (GNO shell-variable table) round-trip regression.
// GNO has no Unix environ[]; the "environment" is the kernel SHELL-
// VARIABLE table reached via GS/OS Shell calls (SetGS $0146 /
// ReadVariableGS $014B) dispatched through the same inline $E100A8
// mechanism as the file calls -- zero new asm.  This probe sets a
// variable, reads it straight back, and asserts the value survives.
//
// Deterministic: the variable name/value are literals, no pids or
// addresses, so the round-trip is identical on every boot.
//
// Bank-2 absolute markers (DBR-independent), per gnoHeapProbe convention:
//   0x025000  C0DE  reached end (no hang in the shell-call path)
//   0x025002  0001  getenv("LLVMTEST") == "42"     (round-trip OK), else DEAD
//   0x025012  0001  setenv("LLVMTEST","42",1) == 0 (call succeeded), else DEAD
#include <stdint.h>
#include <stdlib.h>

#define M(a) (*(volatile uint16_t *)(a))


int main(void) {
    int   sr;
    char *v;
    uint16_t match;

    M(0x025000UL) = 0x0000;

    sr = setenv("LLVMTEST", "42", 1);
    M(0x025012UL) = (sr == 0) ? 0x0001 : 0xDEAD;

    v = getenv("LLVMTEST");
    match = 0xDEAD;
    if (v != 0 && v[0] == '4' && v[1] == '2' && v[2] == 0) {
        match = 0x0001;
    }
    M(0x025002UL) = match;

    M(0x025000UL) = 0xC0DE;                      // reached end
    for (volatile unsigned long j = 0; j < 300000UL; j++) {
    }
    return 0;
}