#include <libpayload.h> // This GETBIT is supposed to work on little endian // 32bit systems. The algorithm will definitely need // some fixing on other systems, but it might not be // a problem since the nrv2b binary behaves the same.. #ifndef ENDIAN #define ENDIAN 0 #endif #ifndef BITSIZE #define BITSIZE 32 #endif #define GETBIT_8(bb, src, ilen) \ (((bb = bb & 0x7f ? bb*2 : ((unsigned)src[ilen++]*2+1)) >> 8) & 1) #define GETBIT_LE16(bb, src, ilen) \ (bb*=2,bb&0xffff ? (bb>>16)&1 : (ilen+=2,((bb=(src[ilen-2]+src[ilen-1]*256u)*2+1)>>16)&1)) #define GETBIT_LE32(bb, src, ilen) \ (bc > 0 ? ((bb>>--bc)&1) : (bc=31,\ bb=*(const u32 *)((src)+ilen),ilen+=4,(bb>>31)&1)) #if ENDIAN == 0 && BITSIZE == 8 #define GETBIT(bb, src, ilen) GETBIT_8(bb, src, ilen) #endif #if ENDIAN == 0 && BITSIZE == 16 #define GETBIT(bb, src, ilen) GETBIT_LE16(bb, src, ilen) #endif #if ENDIAN == 0 && BITSIZE == 32 #define GETBIT(bb, src, ilen) GETBIT_LE32(bb, src, ilen) #endif unsigned long unrv2b(u8 *src, u8 *dst, unsigned long *ilen_p) { unsigned long ilen = 0, olen = 0, last_m_off = 1; u32 bb = 0; unsigned bc = 0; const u8 *m_pos; // skip length src += 4; /* FIXME: check olen with the length stored in first 4 bytes */ for (;;) { unsigned int m_off, m_len; while (GETBIT(bb, src, ilen)) { dst[olen++] = src[ilen++]; } m_off = 1; do { m_off = m_off * 2 + GETBIT(bb, src, ilen); } while (!GETBIT(bb, src, ilen)); if (m_off == 2) { m_off = last_m_off; } else { m_off = (m_off - 3) * 256 + src[ilen++]; if (m_off == 0xffffffffU) break; last_m_off = ++m_off; } m_len = GETBIT(bb, src, ilen); m_len = m_len * 2 + GETBIT(bb, src, ilen); if (m_len == 0) { m_len++; do { m_len = m_len * 2 + GETBIT(bb, src, ilen); } while (!GETBIT(bb, src, ilen)); m_len += 2; } m_len += (m_off > 0xd00); m_pos = dst + olen - m_off; dst[olen++] = *m_pos++; do { dst[olen++] = *m_pos++; } while (--m_len > 0); } *ilen_p = ilen; return olen; }