Kernel: Store the kernel command line in a StringView

The Raspberry Pi's mailbox interface does not guarantee that the
returned command line is null-terminated. This commit removes that
assumption from the current code, allowing the next commit to add
support for reading it on the Pi.

This also lets us eliminate a few manual `strlen()` calls :^)
This commit is contained in:
Daniel Bertalan 2023-04-24 20:14:44 +02:00 committed by Andreas Kling
parent c911fb0150
commit 6aa392f6e4
4 changed files with 10 additions and 14 deletions

View file

@ -133,7 +133,7 @@ READONLY_AFTER_INIT PhysicalAddress boot_pdpt;
READONLY_AFTER_INIT PhysicalAddress boot_pd0;
READONLY_AFTER_INIT PhysicalAddress boot_pd_kernel;
READONLY_AFTER_INIT Memory::PageTableEntry* boot_pd_kernel_pt1023;
READONLY_AFTER_INIT char const* kernel_cmdline;
READONLY_AFTER_INIT StringView kernel_cmdline;
READONLY_AFTER_INIT u32 multiboot_flags;
READONLY_AFTER_INIT multiboot_memory_map_t* multiboot_memory_map;
READONLY_AFTER_INIT size_t multiboot_memory_map_count;
@ -166,7 +166,8 @@ extern "C" [[noreturn]] UNMAP_AFTER_INIT void init([[maybe_unused]] BootInfo con
boot_pd0 = PhysicalAddress { boot_info.boot_pd0 };
boot_pd_kernel = PhysicalAddress { boot_info.boot_pd_kernel };
boot_pd_kernel_pt1023 = (Memory::PageTableEntry*)boot_info.boot_pd_kernel_pt1023;
kernel_cmdline = (char const*)boot_info.kernel_cmdline;
char const* cmdline = (char const*)boot_info.kernel_cmdline;
kernel_cmdline = StringView { cmdline, strlen(cmdline) };
multiboot_flags = boot_info.multiboot_flags;
multiboot_memory_map = (multiboot_memory_map_t*)boot_info.multiboot_memory_map;
multiboot_memory_map_count = boot_info.multiboot_memory_map_count;
@ -192,7 +193,7 @@ extern "C" [[noreturn]] UNMAP_AFTER_INIT void init([[maybe_unused]] BootInfo con
multiboot_module_entry_t modules[] = {};
multiboot_modules = modules;
multiboot_modules_count = 0;
kernel_cmdline = "";
kernel_cmdline = ""sv;
#endif
setup_serial_debug();
@ -442,7 +443,7 @@ UNMAP_AFTER_INIT void setup_serial_debug()
// serial_debug will output all the dbgln() data to COM1 at
// 8-N-1 57600 baud. this is particularly useful for debugging the boot
// process on live hardware.
if (StringView { kernel_cmdline, strlen(kernel_cmdline) }.contains("serial_debug"sv)) {
if (kernel_cmdline.contains("serial_debug"sv)) {
set_serial_debug_enabled(true);
}
}

View file

@ -6,6 +6,7 @@
#pragma once
#include <AK/StringView.h>
#include <Kernel/Multiboot.h>
#include <Kernel/PhysicalAddress.h>
#include <Kernel/VirtualAddress.h>
@ -28,7 +29,7 @@ extern "C" PhysicalAddress boot_pdpt;
extern "C" PhysicalAddress boot_pd0;
extern "C" PhysicalAddress boot_pd_kernel;
extern "C" Kernel::Memory::PageTableEntry* boot_pd_kernel_pt1023;
extern "C" char const* kernel_cmdline;
extern "C" StringView kernel_cmdline;
extern "C" u32 multiboot_flags;
extern "C" multiboot_memory_map_t* multiboot_memory_map;
extern "C" size_t multiboot_memory_map_count;

View file

@ -16,15 +16,9 @@ static char s_cmd_line[1024];
static constexpr StringView s_embedded_cmd_line = ""sv;
static CommandLine* s_the;
UNMAP_AFTER_INIT void CommandLine::early_initialize(char const* cmd_line)
UNMAP_AFTER_INIT void CommandLine::early_initialize(StringView cmd_line)
{
if (!cmd_line)
return;
size_t length = strlen(cmd_line);
if (length >= sizeof(s_cmd_line))
length = sizeof(s_cmd_line) - 1;
memcpy(s_cmd_line, cmd_line, length);
s_cmd_line[length] = '\0';
(void)cmd_line.copy_characters_to_buffer(s_cmd_line, sizeof(s_cmd_line));
}
bool CommandLine::was_initialized()

View file

@ -52,7 +52,7 @@ enum class AHCIResetMode {
class CommandLine {
public:
static void early_initialize(char const* cmd_line);
static void early_initialize(StringView cmd_line);
static void initialize();
static bool was_initialized();