/* image.c -- start a node from a capsule image.  See image.h.
 *
 * Nothing here uses the C library: the bare-metal kernel links this file.
 */
#include "v4/image.h"

int v4_image_boot(v4_node *n, v4_exec_state *es, v4_heat *h, const v4_image *im,
                  unsigned char *disk, unsigned blocks)
{
    unsigned i;

    if (im->cell_bits != (unsigned)V4_CELL_BITS || im->node_words != (unsigned)V4_NODE_WORDS
        || im->data_ring != (unsigned)V4_DATA_RING || im->ret_ring != (unsigned)V4_RET_RING)
        return 0;

    v4_node_reset(n);
    v4_exec_reset(es);
    v4_heat_reset(h);
    for (i = 0; i < im->count; i++)
        if (v4_node_addr_ok(im->cells[i].addr)) n->mem[im->cells[i].addr] = im->cells[i].value;

    v4_node_console_attach(n, im->console_tx);
    v4_node_console_input_attach(n, im->console_rx, im->console_status);
    v4_node_stack_regs_attach(n, im->dstack_reg, im->rstack_reg);
    v4_node_error_attach(n, im->node_error);
    v4_node_fault_attach(n, im->fault_table);
    v4_node_port_attach(n, im->port);
    if (disk && blocks) v4_node_storage_attach(n, im->storage_reg, disk, blocks);

    n->mem[im->line_status] = V4_LINE_COMPLETED;
    n->p = im->idle;
    return 1;
}

int v4_image_waiting(const v4_node *n, const v4_image *im)
{
    return n->input_pos == n->input_len && n->p >= im->key_start && n->p < im->key_end;
}

/* One byte of the node's memory: four to a cell, the first lowest, at either
 * cell width -- as C! stores them (v4/capsule/core.v4). */
static void put_byte(v4_node *n, v4_cell baddr, unsigned c)
{
    v4_cell  word  = baddr / 4;
    unsigned shift = 8u * (unsigned)(baddr % 4);
    v4_ucell mask  = (v4_ucell)0xFFu << shift;
    n->mem[word] = (v4_cell)(((v4_ucell)n->mem[word] & ~mask) | ((v4_ucell)(c & 0xFFu) << shift));
}

int v4_line_begin(v4_node *n, const v4_image *im, const char *text, unsigned len)
{
    unsigned i;

    if (len + 1u > im->tib_bytes) return 0;
    for (i = 0; i < len; i++) put_byte(n, im->tib + (v4_cell)i, (unsigned char)text[i]);
    put_byte(n, im->tib + (v4_cell)len, 0);
    n->mem[im->span] = (v4_cell)len;
    v4_rstack_reset(&n->rs);
    n->p = im->line;
    return 1;
}

int v4_line_done(const v4_node *n, const v4_image *im)
{
    return n->p == im->idle;
}

int v4_line_status(const v4_node *n, const v4_image *im)
{
    return (int)n->mem[im->line_status];
}

void v4_image_seal(v4_node *n, const v4_image *im)
{
    n->mem[im->boot_cells]     = n->mem[im->dp];
    n->mem[im->boot_cells + 1] = n->mem[im->latest];
    n->mem[im->fence]          = (n->mem[im->dp] + 3) / 4;
}