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PackVmlinuzI386::getStrategy(), and Bvmlinuz guesses 60% .text;

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stack for Bvmlinuz uses vacant Vmlinuz low memory (512 KiB)
This commit is contained in:
John Reiser
2008-05-02 04:59:39 -07:00
parent 7266f23450
commit 448a24cb36
5 changed files with 1954 additions and 1940 deletions
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src/p_vmlinz.cpp
+17 -10
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@@ -82,6 +82,13 @@ const int *PackBvmlinuzI386::getFilters() const
return filters;
}
int PackVmlinuzI386::getStrategy(Filter &/*ft*/)
{
// If user specified the filter, then use it (-2==filter_strategy).
// Else try the first two filters, and pick the better (2==filter_strategy).
return (opt->no_filter ? -3 : ((opt->filter > 0) ? -2 : 2));
}
bool PackVmlinuzI386::canPack()
{
@@ -402,7 +409,7 @@ void PackVmlinuzI386::pack(OutputFile *fo)
upx_compress_config_t cconf; cconf.reset();
// limit stack size needed for runtime decompression
cconf.conf_lzma.max_num_probs = 1846 + (768 << 4); // ushort: ~28 KiB stack
compressWithFilters(&ft, 512, &cconf);
compressWithFilters(&ft, 512, &cconf, getStrategy(ft));
const unsigned lsize = getLoaderSize();
@@ -448,7 +455,7 @@ void PackBvmlinuzI386::buildLoader(const Filter *ft)
initLoader(stub_i386_linux_kernel_vmlinuz, sizeof(stub_i386_linux_kernel_vmlinuz));
if (0!=page_offset) { // relocatable kernel
assert(0==ft->id || 0x40==(0xf0 & ft->id)); // others assume fixed buffer address
addLoader("LINUZ000,LINUZVGA,LINUZ101,LINUZ110",
addLoader("LINUZ000,LINUZ001,LINUZVGA,LINUZ101,LINUZ110",
((0!=config_physical_align) ? "LINUZ120" : "LINUZ130"),
"LINUZ140,LZCUTPOI,LINUZ141",
(ft->id ? "LINUZ145" : ""),
@@ -456,7 +463,7 @@ void PackBvmlinuzI386::buildLoader(const Filter *ft)
NULL);
}
else {
addLoader("LINUZ000,LINUZVGA,LINUZ001",
addLoader("LINUZ000,LINUZ001,LINUZVGA,LINUZ005",
ph.first_offset_found == 1 ? "LINUZ010" : "",
(0x40==(0xf0 & ft->id)) ? "LZCKLLT1" : (ft->id ? "LZCALLT1" : ""),
"LBZIMAGE,IDENTSTR",
@@ -511,17 +518,17 @@ void PackBvmlinuzI386::pack(OutputFile *fo)
// prepare filter
Filter ft(ph.level);
ft.buf_len = ph.u_len;
ft.buf_len = (ph.u_len * 3)/5;
// May 2008: 3/5 is heuristic to cover most .text but avoid non-instructions.
// Otherwise "call trick" filter cannot find a free marker byte,
// especially when it searches over tables of data.
ft.addvalue = 0; // The destination buffer might be relocated at runtime.
upx_compress_config_t cconf; cconf.reset();
// limit stack size needed for runtime decompression
cconf.conf_lzma.max_num_probs = 1846 + (768 << 4); // ushort: ~28 KiB stack
// LINUZ001 allows most of low memory as stack for Bvmlinuz
cconf.conf_lzma.max_num_probs = (0x90000 - 0x10000)>>1; // ushort: 512 KiB stack
// FIXME: new stub allows most of low memory as stack for Bvmlinuz ?
//cconf.conf_lzma.max_num_probs = (0x99000 - 0x10250)>>1; // ushort: 560560 stack
compressWithFilters(&ft, 512, &cconf);
compressWithFilters(&ft, 512, &cconf, getStrategy(ft));
// align everything to dword boundary - it is easier to handle
unsigned c_len = ph.c_len;