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Add multiboot image loading, currently only supporting kvm-unit-test (#95, #129)

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copy 2017-04-02 15:14:03 -05:00
parent 612901612c
commit 7b0d0b8084
4 changed files with 208 additions and 3 deletions
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10
index.html
View file

@ -46,7 +46,7 @@
<h4>Setup</h4>
<table>
<tr>
<td width="250">CD image</td>
<td width="350">CD image</td>
<td>
<input type="file" id="cd_image">
</td>
@ -62,6 +62,14 @@
<td><input type="file" id="hd_image"><br></td>
</tr>
<!--
<tr>
<td>Multiboot kernel image (experimental)</td>
<td><input type="file" id="multiboot_image"><br></td>
</tr>
-->
<tr>
<td colspan="2"><small><small>Disk images are not uploaded to the server</small></small><hr></td>
</tr>

13
src/browser/main.js
View file

@ -188,6 +188,16 @@
settings.hda = { buffer: hd_file };
}
if($("multiboot_image"))
{
var multiboot_file = $("multiboot_image").files[0];
if(multiboot_file)
{
last_file = multiboot_file;
settings.multiboot = { buffer: multiboot_file };
}
}
if(last_file)
{
set_title(last_file.name);
@ -474,6 +484,7 @@
settings.fda = infos.fda;
settings.cdrom = infos.cdrom;
settings.hda = infos.hda
settings.multiboot = infos.multiboot
settings.memory_size = infos.memory_size;
settings.vga_memory_size = infos.vga_memory_size;
@ -689,6 +700,8 @@
"hda": settings.hda,
"cdrom": settings.cdrom,
"multiboot": settings.multiboot,
"initial_state": settings.initial_state,
"filesystem": settings.filesystem || {},

9
src/browser/starter.js
View file

@ -167,6 +167,10 @@ function V86Starter(options)
settings.fdb = this.disk_images["fdb"] = buffer;
break;
case "multiboot":
settings.multiboot = this.disk_images["multiboot"] = buffer;
break;
case "bios":
settings.bios = buffer.buffer;
break;
@ -211,7 +215,8 @@ function V86Starter(options)
size: file["size"],
};
if(name === "bios" || name === "vga_bios" || name === "initial_state")
if(name === "bios" || name === "vga_bios" ||
name === "initial_state" || name === "multiboot")
{
// Ignore async for these because they must be availabe before boot.
// This should make result.buffer available after the object is loaded
@ -285,7 +290,7 @@ function V86Starter(options)
var image_names = [
"bios", "vga_bios",
"cdrom", "hda", "hdb", "fda", "fdb",
"initial_state",
"initial_state", "multiboot",
];
for(var i = 0; i < image_names.length; i++)

179
src/cpu.js
View file

@ -720,12 +720,191 @@ CPU.prototype.init = function(settings, device_bus)
}
}
if(settings.multiboot)
{
dbg_assert(settings.multiboot.buffer);
this.load_multiboot(settings.multiboot.buffer);
}
if(DEBUG)
{
this.debug.init();
}
};
CPU.prototype.load_multiboot = function(buffer)
{
// https://www.gnu.org/software/grub/manual/multiboot/multiboot.html
dbg_log("Trying multiboot from buffer of size " + buffer.byteLength, LOG_CPU);
const MAGIC = 0x1BADB002;
const ELF_MAGIC = 0x464C457F;
const MULTIBOOT_HEADER_ADDRESS = 0x10000;
const MULTIBOOT_SEARCH_BYTES = 8192;
var buf32 = new Int32Array(buffer);
for(var offset = 0; offset < MULTIBOOT_SEARCH_BYTES; offset += 4)
{
if(buf32[offset >> 2] === MAGIC)
{
var flags = buf32[offset + 4 >> 2];
var checksum = buf32[offset + 8 >> 2];
var total = MAGIC + flags + checksum | 0;
if(total)
{
dbg_log("Multiboot checksum check failed", LOG_CPU);
continue
}
}
else
{
continue;
}
dbg_log("Multiboot magic found, flags: " + h(flags >>> 0, 8), LOG_CPU);
dbg_assert((flags & ~MULTIBOOT_HEADER_ADDRESS) === 0, "TODO");
this.reg32s[reg_eax] = 0x2BADB002;
let multiboot_info_addr = 0x7C00
this.reg32s[reg_ebx] = multiboot_info_addr;
this.write32(multiboot_info_addr, 0);
this.cr[0] = 1;
this.protected_mode = true;
this.flags = flags_default
this.update_cs_size(true);
this.stack_size_32 = true;
for(var i = 0; i < 6; i++)
{
this.segment_is_null[i] = 0;
this.segment_offsets[i] = 0;
this.segment_limits[i] = 0xFFFFFFFF;
// Value doesn't matter, OS isn't allowed to reload without setting
// up a proper GDT
this.sreg[i] = 0xB002;
}
if(flags & MULTIBOOT_HEADER_ADDRESS)
{
dbg_log("Multiboot specifies its own address table", LOG_CPU);
var header_addr = buf32[offset + 12 >> 2];
var load_addr = buf32[offset + 16 >> 2];
var load_end_addr = buf32[offset + 20 >> 2];
var bss_end_addr = buf32[offset + 24 >> 2];
var entry_addr = buf32[offset + 28 >> 2];
dbg_log("header=" + h(header_addr, 8) +
" load=" + h(load_addr, 8) +
" load_end=" + h(load_end_addr, 8) +
" bss_end=" + h(bss_end_addr, 8) +
" entry=" + h(entry_addr, 8))
dbg_assert(load_addr <= header_addr);
var file_start = offset - (header_addr - load_addr);
if(load_end_addr === 0)
{
var length = undefined;
}
else
{
dbg_assert(load_end_addr >= load_addr);
var length = load_end_addr - load_addr;
}
let blob = new Uint8Array(buffer, file_start, length);
this.write_blob(blob, load_addr);
this.instruction_pointer = this.get_seg(reg_cs) + entry_addr | 0;
}
else if(buf32[0] === ELF_MAGIC)
{
dbg_log("Multiboot image is in elf format", LOG_CPU);
let elf = read_elf(buffer);
this.instruction_pointer = this.get_seg(reg_cs) + elf.header.entry | 0;
for(let program of elf.program_headers)
{
if(program.type === 0)
{
// null
}
else if(program.type === 1)
{
// load
// Since multiboot specifies that paging is disabled,
// virtual and physical address must be equal
dbg_assert(program.paddr === program.vaddr);
dbg_assert(program.filesz <= program.memsz);
let blob = new Uint8Array(buffer, program.offset, program.filesz);
this.write_blob(blob, program.paddr);
}
else if(program.type === 4 ||
program.type === 0x6474e550 ||
program.type === 0x6474e551)
{
// ignore for now
}
else
{
dbg_assert(false, "unimplemented elf section type");
}
}
}
else
{
dbg_assert(false, "Not a bootable multiboot format");
}
// only for kvm-unit-test
this.io.register_write_consecutive(0xF4, this,
function(value)
{
console.log("Test exited with code " + h(value, 2));
throw "HALT";
},
function() {},
function() {},
function() {});
// only for kvm-unit-test
for(let i = 0xE; i <= 0xF; i++)
{
this.io.register_write(0x2000 + i, this,
function(value)
{
dbg_log("kvm-unit-test: Set irq " + h(i) + " to " + h(value, 2));
if(value)
{
this.device_raise_irq(i);
}
else
{
this.device_lower_irq(i);
}
});
}
dbg_log("Starting multiboot kernel at:", LOG_CPU);
this.debug.dump_state();
this.debug.dump_regs();
break;
}
};
CPU.prototype.fill_cmos = function(rtc, settings)
{
var boot_order = settings.boot_order || 0x213;