Function sys_cap_create 

pub fn sys_cap_create(_rights: u64) -> SyscallResult<u64>

Create a new capability with the specified rights bitmask.

Allocates a new capability token and inserts it into the calling process’s capability space. The new capability is derived from the caller’s parent (root) capability; the caller can only create capabilities with a subset of rights that it already holds.

Capability tokens are unforgeable 64-bit values with an embedded generation counter used for efficient revocation. The token uniquely identifies the capability across the entire system.

Arguments

• rights - Bitmask of rights to assign to the new capability:

  • CAP_READ (0x01) - Permission to read or receive.
  • CAP_WRITE (0x02) - Permission to write or send.
  • CAP_EXECUTE (0x04) - Permission to execute.
  • CAP_GRANT (0x08) - Permission to grant this capability to other processes via sys_cap_grant.
  • CAP_REVOKE (0x10) - Permission to revoke derived capabilities.
  • CAP_MAP (0x20) - Permission to map associated memory regions.

  Rights are subtractive: you cannot create a capability with rights exceeding those of the parent capability.

Returns

• Ok(cap_token) - The 64-bit capability token for the newly created capability.

Errors

• SyscallError::PermissionDenied - The caller does not hold a parent capability with the requested rights, or lacks the ability to create new capabilities.
• SyscallError::InvalidArgument - rights is zero or contains undefined bits.
• SyscallError::OutOfMemory - The capability table is full and cannot accommodate a new entry.

Examples

use veridian_kernel::pkg::sdk::syscall_api::sys_cap_create;

// Create a read-only capability
let cap_ro = sys_cap_create(0x01).expect("cap_create failed");

// Create a read-write-grant capability
let cap_rwg = sys_cap_create(0x01 | 0x02 | 0x08).expect("cap_create failed");