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bvmlinuz boot protocol 2.08 (not yet complete?)

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This commit is contained in:
John Reiser 2008-08-04 17:30:44 -07:00
parent 0b31fbf827
commit 86de510731
2 changed files with 11 additions and 7 deletions
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17
src/p_vmlinz.cpp
View File

@ -53,6 +53,7 @@ static const unsigned bzimage_offset = 0x100000;
PackVmlinuzI386::PackVmlinuzI386(InputFile *f) :
super(f), physical_start(0x100000), page_offset(0), config_physical_align(0)
, filter_len(0)
{
bele = &N_BELE_RTP::le_policy;
COMPILE_TIME_ASSERT(sizeof(boot_sect_t) == 0x250);
@ -166,6 +167,10 @@ int PackVmlinuzI386::decompressKernel()
unsigned cpa_0 = 0;
unsigned cpa_1 = 0;
int j;
if (0x205<=h.version) {
cpa_0 = h.kernel_alignment;
cpa_1 = 0u - cpa_0;
} else
for ((p = &obuf[setup_size]), (j= 0); j < 0x200; ++j, ++p) {
if (0==memcmp("\x89\xeb\x81\xc3", p, 4)
&& 0==memcmp("\x81\xe3", 8+ p, 2)) {
@ -292,7 +297,7 @@ int PackVmlinuzI386::decompressKernel()
continue;
if (0x208<=h.version && 0==memcmp("\177ELF", ibuf, 4)) {
// Full ELF in theory; but for now, try to handle as .bin at 0x100000.
// Full ELF in theory; for now, try to handle as .bin at physical_start.
// Check for PT_LOAD.p_paddr being ascending and adjacent.
Elf_LE32_Ehdr const *const ehdr = (Elf_LE32_Ehdr const *)(void const *)ibuf;
Elf_LE32_Phdr const *phdr = (Elf_LE32_Phdr const *)(ehdr->e_phoff + (char const *)ehdr);
@ -303,8 +308,8 @@ int PackVmlinuzI386::decompressKernel()
if (phdr->PT_LOAD==phdr->p_type) {
unsigned step = (-1+ phdr->p_align + hi_paddr) & ~(-1+ phdr->p_align);
if (0==hi_paddr) { // first PT_LOAD
if (0x100000!=phdr->p_paddr) {
return 0; // Not at traditional location.
if (physical_start!=phdr->p_paddr) {
return 0;
}
delta_off = phdr->p_paddr - phdr->p_offset;
lo_paddr = phdr->p_paddr;
@ -319,19 +324,17 @@ int PackVmlinuzI386::decompressKernel()
}
}
}
unsigned xlen = 0;
// FIXME: ascending order is only a convention; might need sorting.
for (unsigned j=1; j < ehdr->e_shnum; ++j) {
if (shdr->SHT_PROGBITS==shdr->sh_type) { // SHT_REL might be intermixed
if (shdr->SHF_EXECINSTR & shdr[j].sh_flags) {
xlen += shdr[j].sh_size; // FIXME: include sh_addralign
filter_len += shdr[j].sh_size; // FIXME: include sh_addralign
}
else {
break;
}
}
}
//printf("xlen = 0x%x\n", xlen); // FIXME: use as length to filter
memmove(ibuf, (lo_paddr - delta_off) + ibuf, hi_paddr - lo_paddr); // FIXME: set_size
// FIXME: .bss ? Apparently handled by head.S
}
@ -567,7 +570,7 @@ void PackBvmlinuzI386::pack(OutputFile *fo)
// prepare filter
Filter ft(ph.level);
ft.buf_len = (ph.u_len * 3)/5;
ft.buf_len = (filter_len ? filter_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.

1
src/p_vmlinz.h
View File

@ -97,6 +97,7 @@ protected:
unsigned physical_start;
unsigned page_offset;
unsigned config_physical_align;
unsigned filter_len;
};