121 lines
2.3 KiB
C++
121 lines
2.3 KiB
C++
#include <fxos/os.h>
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#include <fxos/target.h>
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#include <fxos/memory.h>
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#include <cstring>
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namespace FxOS {
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OS::OS(Buffer &buffer): target()
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{
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/* OS files are all at least 1 MB large */
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if(buffer.size() < 1000000)
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throw std::runtime_error("OS files cannot be < 1MB");
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/* Bind the given file to the internal analysis target */
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this->target.bind_region(MemoryRegion::ROM, buffer);
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this->target.bind_region(MemoryRegion::ROM_P2, buffer);
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parse_header();
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parse_syscall_table();
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parse_footer();
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}
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void OS::parse_header()
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{
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Target &t = this->target;
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/* Bootcode timestamp at 0xffb0 (the very end of the bootcode) */
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this->bootcode_timestamp = t.read_str(0x8000ffb0, 14);
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/* Bootcode checksum at 0xfffc */
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this->bootcode_checksum = t.read_u32(0x8000fffc);
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/* Version string at 0x10020 */
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this->version = t.read_str(0x80010020, 10);
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/* Serial numer at 0xffd0... sometimes? */
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this->serial_number = t.read_str(0x8000ffd0, 8);
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}
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//---
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// Syscall resolution
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//---
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int OS::syscall_count() const noexcept
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{
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return m_syscall_table.size();
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}
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uint32_t OS::syscall(int id) const
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{
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return m_syscall_table[id];
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}
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int OS::find_syscall(uint32_t entry) const noexcept
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{
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try {
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return m_syscall_addresses.at(entry);
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}
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catch(std::out_of_range &e) {
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return -1;
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}
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}
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void OS::parse_syscall_table()
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{
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Target &t = this->target;
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/* Traverse the syscall table */
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uint32_t syscall_table = t.read_u32(0x8001007c);
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int id = 0;
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while(1)
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{
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uint32_t entry = t.read_u32(syscall_table + 4 * id);
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MemoryRegion const *r = MemoryRegion::region_for(entry);
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if(!r) break;
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m_syscall_table.push_back(entry);
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m_syscall_addresses[entry] = id;
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id++;
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}
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}
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//---
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// Footer search
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//---
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void OS::parse_footer()
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{
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Target &t = this->target;
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/* Find the footer address (occurrence of "CASIOABSLangdata") */
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uint32_t start = MemoryRegion::ROM.start;
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uint32_t end = MemoryRegion::ROM.end;
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this->footer = t.search(start, end, "CASIOABSLangdata", 16);
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if(this->footer == end)
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{
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this->footer = -1;
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this->timestamp = std::string("");
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this->bootcode_timestamp = std::string("");
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this->langdata = 0;
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return;
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}
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uint32_t addr = this->footer + 8;
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this->langdata = 0;
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while(!memcmp(t.translate(addr, 8), "Langdata", 8))
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{
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this->langdata++;
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addr += 0x30;
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}
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this->timestamp = t.read_str(addr, 14);
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this->checksum = t.read_u32(addr + 0x18);
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}
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} /* namespace FxOS */
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