usb_msc_bounds.h

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// Pure bounds/alignment validation for a USB MSC block access.
//
// Kept dependency-free (stdint/stdbool only) so it is shared by the firmware
// block layer and host unit tests.
 
#pragma once
 
#include <stdint.h>
#include <stdbool.h>

static inline bool usb_msc_range_ok(uint64_t total_bytes, uint16_t block_size,
                                    uint32_t lba, uint32_t offset, uint32_t len,
                                    bool is_write) {
    if (block_size == 0) return false;
    if (is_write && (offset != 0 || (len % block_size) != 0)) return false;
    uint64_t addr = (uint64_t)lba * block_size + offset;
    if (addr + len > total_bytes) return false;
    return true;
}

static inline bool usb_msc_should_remount(bool prev, bool cur) {
    return prev && !cur;
}