banner.hpp

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/**
 * @file banner.hpp
 * @brief Boot banner formatter
 *
 * Formats a startup banner with app name, build info, MCU metadata,
 * and audio configuration. Uses __has_include for optional headers
 * so it works in both firmware and unit test builds.
 *
 * Usage:
 *   #include <sbl/log/banner.hpp>
 *
 *   char buf[384];
 *   int len = sbl::log::format_banner(buf, sizeof(buf),
 *       "hello-instrument", 48000, 48);
 *   SBL_LOG_OUTPUT::write(buf);
 *
 * Gated behind SBL_BOOT_BANNER (default: 1). Set to 0 to disable.
 */
#pragma once
 
#include <cstddef>
#include <cstdint>
 
#ifndef SBL_BOOT_BANNER
#define SBL_BOOT_BANNER 1
#endif
 
// Optional constexpr-only headers — silently omitted when absent
#if __has_include(<sbl/hw/config/mcu.hpp>)
#include <sbl/hw/config/mcu.hpp>
#define SBL_BANNER_HAS_MCU 1
#else
#define SBL_BANNER_HAS_MCU 0
#endif
 
#if __has_include(<sbl/hw/config/system.hpp>)
#include <sbl/hw/config/system.hpp>
#define SBL_BANNER_HAS_SYSTEM 1
#else
#define SBL_BANNER_HAS_SYSTEM 0
#endif
 
#if __has_include(<sbl/version.hpp>)
#include <sbl/version.hpp>
#define SBL_BANNER_HAS_VERSION 1
#else
#define SBL_BANNER_HAS_VERSION 0
#endif
 
namespace sbl::log {
 
namespace detail {
 
// Minimal string append helpers — no printf dependency
inline int banner_append(char* buf, size_t size, int pos, const char* str) {
    while (*str && static_cast<size_t>(pos) < size - 1) {
        buf[pos++] = *str++;
    }
    return pos;
}
 
inline int banner_append_uint(char* buf, size_t size, int pos, uint32_t val) {
    char tmp[12];
    int len = 0;
    if (val == 0) {
        tmp[len++] = '0';
    } else {
        char rev[12];
        int rlen = 0;
        while (val > 0) {
            rev[rlen++] = static_cast<char>('0' + (val % 10));
            val /= 10;
        }
        while (rlen > 0) tmp[len++] = rev[--rlen];
    }
    for (int i = 0; i < len && static_cast<size_t>(pos) < size - 1; ++i) {
        buf[pos++] = tmp[i];
    }
    return pos;
}
 
} // namespace detail
 
/**
 * @brief Format a boot banner into a buffer
 *
 * @param buf Output buffer
 * @param size Buffer size (recommend >= 384)
 * @param app_name Application name (e.g., "hello-instrument")
 * @param sample_rate Audio sample rate in Hz (e.g., 48000)
 * @param block_size Audio block size in frames (e.g., 48)
 * @return Number of characters written (excluding null terminator)
 */
inline int format_banner(char* buf, size_t size, const char* app_name,
                         uint32_t sample_rate, uint16_t block_size) {
#if !SBL_BOOT_BANNER
    (void)app_name; (void)sample_rate; (void)block_size;
    if (size > 0) buf[0] = '\0';
    return 0;
#else
    if (size == 0 || buf == nullptr) return 0;
 
    int p = 0;
    const char* sep = "======================================\r\n";
 
    p = detail::banner_append(buf, size, p, sep);
 
    // App name + version
    p = detail::banner_append(buf, size, p, "  ");
    p = detail::banner_append(buf, size, p, app_name);
#if SBL_BANNER_HAS_VERSION
    p = detail::banner_append(buf, size, p, " (sbl ");
    p = detail::banner_append(buf, size, p, sbl::version::string);
    p = detail::banner_append(buf, size, p, ")");
#endif
    p = detail::banner_append(buf, size, p, "\r\n");
 
    // Build date/time
    p = detail::banner_append(buf, size, p, "  Built: ");
    p = detail::banner_append(buf, size, p, __DATE__);
    p = detail::banner_append(buf, size, p, " ");
    p = detail::banner_append(buf, size, p, __TIME__);
    p = detail::banner_append(buf, size, p, "\r\n");
 
    // MCU info
#if SBL_BANNER_HAS_MCU
    p = detail::banner_append(buf, size, p, "  MCU: ");
    p = detail::banner_append(buf, size, p, sbl::hw::mcu::name);
#if SBL_BANNER_HAS_SYSTEM
    p = detail::banner_append(buf, size, p, " @ ");
    p = detail::banner_append_uint(buf, size, p, sbl::hw::system::sysclk_mhz);
    p = detail::banner_append(buf, size, p, " MHz");
#endif
    p = detail::banner_append(buf, size, p, "\r\n");
#endif
 
    // Audio config
    p = detail::banner_append(buf, size, p, "  Audio: ");
    p = detail::banner_append_uint(buf, size, p, sample_rate);
    p = detail::banner_append(buf, size, p, " Hz / ");
    p = detail::banner_append_uint(buf, size, p, block_size);
    p = detail::banner_append(buf, size, p, " frames\r\n");
 
    // Profiling status
#ifdef SBL_PROFILING_ENABLED
    p = detail::banner_append(buf, size, p, "  Profiling: enabled\r\n");
#endif
 
    // Git info
#if SBL_BANNER_HAS_VERSION
    p = detail::banner_append(buf, size, p, "  Git: ");
    p = detail::banner_append(buf, size, p, sbl::version::git_hash);
    if (sbl::version::git_dirty) {
        p = detail::banner_append(buf, size, p, "-dirty");
    }
    p = detail::banner_append(buf, size, p, "\r\n");
#endif
 
    p = detail::banner_append(buf, size, p, sep);
 
    buf[static_cast<size_t>(p) < size ? p : size - 1] = '\0';
    return p;
#endif // SBL_BOOT_BANNER
}
 
} // namespace sbl::log