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author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:09:50 -0800 |
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committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:21:03 -0800 |
commit | 71e4f3812982dba2efb471283d310224e8db363e (patch) | |
tree | ea111a1acb8b8845dbda39c0e1b4bac1d198143b /linux/bootstrap/019functions.cc | |
parent | c6b928be29ac8cdb4e4d6e1eaa20420ff03e5a4c (diff) | |
download | mu-71e4f3812982dba2efb471283d310224e8db363e.tar.gz |
7842 - new directory organization
Baremetal is now the default build target and therefore has its sources at the top-level. Baremetal programs build using the phase-2 Mu toolchain that requires a Linux kernel. This phase-2 codebase which used to be at the top-level is now under the linux/ directory. Finally, the phase-2 toolchain, while self-hosting, has a way to bootstrap from a C implementation, which is now stored in linux/bootstrap. The bootstrap C implementation uses some literate programming tools that are now in linux/bootstrap/tools. So the whole thing has gotten inverted. Each directory should build one artifact and include the main sources (along with standard library). Tools used for building it are relegated to sub-directories, even though those tools are often useful in their own right, and have had lots of interesting programs written using them. A couple of things have gotten dropped in this process: - I had old ways to run on just a Linux kernel, or with a Soso kernel. No more. - I had some old tooling for running a single test at the cursor. I haven't used that lately. Maybe I'll bring it back one day. The reorg isn't done yet. Still to do: - redo documentation everywhere. All the README files, all other markdown, particularly vocabulary.md. - clean up how-to-run comments at the start of programs everywhere - rethink what to do with the html/ directory. Do we even want to keep supporting it? In spite of these shortcomings, all the scripts at the top-level, linux/ and linux/bootstrap are working. The names of the scripts also feel reasonable. This is a good milestone to take stock at.
Diffstat (limited to 'linux/bootstrap/019functions.cc')
-rw-r--r-- | linux/bootstrap/019functions.cc | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/linux/bootstrap/019functions.cc b/linux/bootstrap/019functions.cc new file mode 100644 index 00000000..2fde10ef --- /dev/null +++ b/linux/bootstrap/019functions.cc @@ -0,0 +1,122 @@ +//:: call + +:(before "End Initialize Op Names") +put_new(Name, "e8", "call disp32 (call)"); + +:(code) +void test_call_disp32() { + Mem.push_back(vma(0xbd000000)); // manually allocate memory + Reg[ESP].u = 0xbd000064; + run( + "== code 0x1\n" + // op ModR/M SIB displacement immediate + " e8 a0 00 00 00 \n" // call function offset at 0xa0 + // next EIP is 6 + ); + CHECK_TRACE_CONTENTS( + "run: call imm32 0x000000a0\n" + "run: decrementing ESP to 0xbd000060\n" + "run: pushing value 0x00000006\n" + "run: jumping to 0x000000a6\n" + ); +} + +:(before "End Single-Byte Opcodes") +case 0xe8: { // call disp32 relative to next EIP + const int32_t offset = next32(); + ++Callstack_depth; + trace(Callstack_depth+1, "run") << "call imm32 0x" << HEXWORD << offset << end(); +//? cerr << "push: EIP: " << EIP << " => " << Reg[ESP].u << '\n'; + push(EIP); + EIP += offset; + trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end(); + break; +} + +//: + +:(code) +void test_call_r32() { + Mem.push_back(vma(0xbd000000)); // manually allocate memory + Reg[ESP].u = 0xbd000064; + Reg[EBX].u = 0x000000a0; + run( + "== code 0x1\n" + // op ModR/M SIB displacement immediate + " ff d3 \n" // call function offset at EBX + // next EIP is 3 + ); + CHECK_TRACE_CONTENTS( + "run: call to r/m32\n" + "run: r/m32 is EBX\n" + "run: decrementing ESP to 0xbd000060\n" + "run: pushing value 0x00000003\n" + "run: jumping to 0x000000a0\n" + ); +} + +:(before "End Op ff Subops") +case 2: { // call function pointer at r/m32 + trace(Callstack_depth+1, "run") << "call to r/m32" << end(); + const int32_t* offset = effective_address(modrm); + push(EIP); + EIP = *offset; + trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end(); + ++Callstack_depth; + break; +} + +:(code) +void test_call_mem_at_rm32() { + Mem.push_back(vma(0xbd000000)); // manually allocate memory + Reg[ESP].u = 0xbd000064; + Reg[EBX].u = 0x2000; + run( + "== code 0x1\n" + // op ModR/M SIB displacement immediate + " ff 13 \n" // call function offset at *EBX + // next EIP is 3 + "== data 0x2000\n" + "a0 00 00 00\n" // 0xa0 + ); + CHECK_TRACE_CONTENTS( + "run: call to r/m32\n" + "run: effective address is 0x00002000 (EBX)\n" + "run: decrementing ESP to 0xbd000060\n" + "run: pushing value 0x00000003\n" + "run: jumping to 0x000000a0\n" + ); +} + +//:: ret + +:(before "End Initialize Op Names") +put_new(Name, "c3", "return from most recent unfinished call (ret)"); + +:(code) +void test_ret() { + Mem.push_back(vma(0xbd000000)); // manually allocate memory + Reg[ESP].u = 0xbd000064; + write_mem_u32(Reg[ESP].u, 0x10); + run( + "== code 0x1\n" + // op ModR/M SIB displacement immediate + " c3 \n" // return + "== data 0x2000\n" + "10 00 00 00\n" // 0x10 + ); + CHECK_TRACE_CONTENTS( + "run: return\n" + "run: popping value 0x00000010\n" + "run: jumping to 0x00000010\n" + ); +} + +:(before "End Single-Byte Opcodes") +case 0xc3: { // return from a call + trace(Callstack_depth+1, "run") << "return" << end(); + --Callstack_depth; + EIP = pop(); + trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end(); + break; +} |