From faa33d89a272a77e647d540e7b85dfcf8a9b75ee Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Mon, 30 Apr 2007 13:48:50 -0700
Subject: [PATCH] Documentation:  UPX_F_VMLINUX_PPC32 changes to
 arch/powerpc/boot/main.c

---
 src/p_vmlinx.cpp | 103 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/src/p_vmlinx.cpp b/src/p_vmlinx.cpp
index e0718761..308335eb 100644
--- a/src/p_vmlinx.cpp
+++ b/src/p_vmlinx.cpp
@@ -331,6 +331,109 @@ void PackVmlinuxBase<T>::pack(OutputFile *fo)
         hdr_info.b_cto8 = ft.cto;
         fo->write(&hdr_info, sizeof(hdr_info)); fo_off += sizeof(hdr_info);
         ppc32_extra += sizeof(hdr_info);
+
+#if 0  /*{ Documentation: changes to arch/powerpc/boot/main.c */
+struct b_info {
+	unsigned sz_unc;
+	unsigned sz_cpr;
+	unsigned char b_method;
+	unsigned char b_ftid;
+	unsigned char b_cto8;
+	unsigned char b_unused;
+};
+typedef int (*upx_f_unc)(  /* uncompress */
+	unsigned char const *src, unsigned  src_len,
+	unsigned char       *dst, unsigned *dst_len,
+	int method
+);
+typedef int (*upx_f_unf)(  /* unfilter */
+	unsigned char *buf,
+	unsigned len,
+	unsigned cto8,
+	unsigned ftid
+);
+
+unsigned char const *upx_expand(  // return updated src [aligned, too]
+	unsigned char const *src,
+	unsigned char       *dst,
+	unsigned *const dst_len,
+	upx_f_unc const f_unc
+)
+{
+	if (0==*dst_len) {
+		*dst_len = ((struct b_info const *)src)->sz_unc;
+	}
+	upx_f_unf const f_unf = (upx_f_unf)(sizeof(int) + (char *)f_unc);
+	unsigned total_len = 0;
+	unsigned need = *dst_len;
+	while (0 < need) {
+		struct b_info const *const b_hdr = (struct b_info const *)src;
+		src = (unsigned char const *)(1+ b_hdr);
+		unsigned blk_len = b_hdr->sz_unc;
+		int const rv = (*f_unc)(src, b_hdr->sz_cpr, dst, &blk_len, b_hdr->b_method);
+		if (0!=rv) {
+			printf("decompress error %d\n\r", rv);
+			exit();
+		}
+		if (b_hdr->b_ftid) {
+			(*f_unf)(dst, b_hdr->sz_unc, b_hdr->b_cto8, b_hdr->b_ftid);
+		}
+		src += b_hdr->sz_cpr;
+		src += (3& -(int)src);  // 4-byte align
+		dst += b_hdr->sz_unc;
+		total_len += b_hdr->sz_unc;
+		need -= b_hdr->sz_unc;
+	}
+	*dst_len = total_len;
+	return src;
+}
+
+void prep_kernel(unsigned long a1, unsigned long a2)
+{
+	upx_f_unc f_unc = (upx_f_unc)0;
+
+	vmlinuz.addr = (unsigned long)_vmlinux_start;
+	vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
+
+	if (0x55505821 == *(unsigned *)vmlinuz.addr) {
+		/* was compressed by upx */
+		/* Uncompress elfheader */
+		unsigned const *const fwa = (unsigned *)vmlinuz.addr;
+		f_unc = (upx_f_unc)((char *)&fwa[2] + fwa[1]);
+		unsigned dst_len = 0;
+		unsigned char const *src = (unsigned char const *)&fwa[2];
+		src = upx_expand(src, (unsigned char *)elfheader, &dst_len, f_unc);
+		unsigned const src_len = src - (unsigned char const *)&fwa[0];
+		vmlinuz.addr += src_len;
+		vmlinuz.size -= src_len;
+	} else {
+		memcpy(elfheader, (const void *)vmlinuz.addr,
+		       sizeof(elfheader));
+	}
+=====
+	/* Eventually gunzip the kernel */
+	if (f_unc) {
+		/* was compressed by upx */
+		printf("upx_expand (0x%lx <- 0x%lx:0x%0lx)...",
+		       vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
+		unsigned dst_len = vmlinux.size - elfoffset;
+		upx_expand((unsigned char const *)vmlinuz.addr,
+		           (unsigned char       *)vmlinux.addr, &dst_len, f_unc);
+		printf("done 0x%lx bytes\n\r", len);
+	} else {
+		memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
+			vmlinuz.size);
+		/* Skip over the ELF header */
+#ifdef DEBUG
+		printf("... skipping 0x%lx bytes of ELF header\n\r",
+				elfoffset);
+#endif
+		vmlinux.addr += elfoffset;
+	}
+=====
+}
+#endif  /*}*/
+
     }
     else {
         compressWithFilters(&ft, 512, &cconf, getStrategy(ft));