musl/arch/powerpc/bits/user.h

struct pt_regs {
	unsigned long gpr[32], nip, msr, orig_gpr3, ctr, link, xer, ccr, mq;
	unsigned long trap, dar, dsisr, result;
};

struct user {
	struct pt_regs regs;
	unsigned long u_tsize, u_dsize, u_ssize;
	unsigned long start_code, start_data, start_stack;
	long signal;
	void *u_ar0;
	unsigned long magic;
	char u_comm[32];
};