#pragma once

#include "stdint.h"

#define OPC_MAGIC           0x0143504F   /* 'O', 'P', 'C', 0x01 */
#define OPC_ARCH_X86_64     0x8664
#define OPC_VERSION_1       1

/* Capability flags for OPC binaries */
#define OPC_CAP_KERNEL_CTRL (1 << 0)
#define OPC_CAP_UART        (1 << 1)
#define OPC_CAP_NET         (1 << 2)
#define OPC_CAP_FB          (1 << 3)
#define OPC_CAP_NOTIFY      (1 << 4)
#define OPC_CAP_ALL         0xFFFFFFFF

/* Segment flags */
#define OPC_SEG_X           (1 << 0)  /* Executable */
#define OPC_SEG_W           (1 << 1)  /* Writable */
#define OPC_SEG_R           (1 << 2)  /* Readable */

#define OPC_SEG_TYPE_LOAD   1

#ifdef __cplusplus
extern "C" {
#endif

typedef struct opc_header {
    uint32_t magic;           /* OPC_MAGIC ("OPC\x01") */
    uint16_t version;         /* OPC_VERSION_1 */
    uint16_t arch;            /* OPC_ARCH_X86_64 */
    uint64_t entry_rip;       /* Virtual address of entry point */
    uint64_t stack_size;      /* Required user stack size (bytes, e.g. 65536) */
    uint32_t caps_mask;       /* Required capability bitmask */
    uint8_t  preferred_core;  /* Preferred CPU core (0..3, or 0xFF = any) */
    uint8_t  num_segments;    /* Number of opc_segment_t headers following */
    uint16_t reserved;        /* Alignment padding */
} __attribute__((packed)) opc_header_t;

typedef struct opc_segment {
    uint32_t seg_type;        /* OPC_SEG_TYPE_LOAD */
    uint32_t flags;           /* OPC_SEG_R | OPC_SEG_W | OPC_SEG_X */
    uint64_t file_offset;     /* Offset within the .opc file */
    uint64_t vaddr;           /* Target virtual address */
    uint64_t filesz;          /* Size in file (bytes) */
    uint64_t memsz;           /* Size in memory (bytes, memsz >= filesz, rest is BSS) */
    uint64_t align;           /* Alignment requirement (usually 4096) */
} __attribute__((packed)) opc_segment_t;

#ifdef __cplusplus
}
#endif