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Kernel: Add better support for bootloaders loading the kernel

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Before I assumed that bootloaders loaded the kernel at physical address
0, but this patch kinda allows loading to different addresses. This
still doesn't fully work as kernel bootstrap paging relies on kernel
being loaded at 0
This commit is contained in:
Bananymous
2024-08-22 14:20:51 +03:00
parent abc788c756
commit fb35f06cf5
10 changed files with 40 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
kernel/kernel/ACPI/ACPI.cpp
View File

@@ -254,7 +254,7 @@ acpi_release_global_lock:
return *s_instance;
}
static bool is_rsdp(uintptr_t rsdp_addr)
static bool is_rsdp(vaddr_t rsdp_addr)
{
const RSDP* rsdp = (const RSDP*)rsdp_addr;
@@ -287,7 +287,7 @@ acpi_release_global_lock:
return &g_boot_info.rsdp;
// Look in main BIOS area below 1 MB
for (uintptr_t addr = P2V(0x000E0000); addr < P2V(0x000FFFFF); addr += 16)
for (vaddr_t addr = 0x000E0000 + KERNEL_OFFSET; addr < 0x000FFFFF + KERNEL_OFFSET; addr += 16)
if (is_rsdp(addr))
return reinterpret_cast<const RSDP*>(addr);
return nullptr;

4
kernel/kernel/BootInfo.cpp
View File

@@ -66,6 +66,8 @@ namespace Kernel
memcpy(&g_boot_info.rsdp, &rsdp, BAN::Math::min<uint32_t>(rsdp.length, sizeof(g_boot_info.rsdp)));
}
}
g_boot_info.kernel_paddr = 0;
}
static BAN::StringView get_early_boot_command_line_multiboot2(uint32_t info)
@@ -104,6 +106,8 @@ namespace Kernel
g_boot_info.memory_map_entries[i].length = mmap_entry.length;
g_boot_info.memory_map_entries[i].type = mmap_entry.type;
}
g_boot_info.kernel_paddr = banan_bootloader_info.kernel_paddr;
}
static BAN::StringView get_early_boot_command_line_banan_bootloader(uint32_t info)

4
kernel/kernel/Memory/Heap.cpp
View File

@@ -40,8 +40,8 @@ namespace Kernel
continue;
paddr_t start = entry.address;
if (start < V2P(g_kernel_end))
start = V2P(g_kernel_end);
if (start < (vaddr_t)g_kernel_end - KERNEL_OFFSET + g_boot_info.kernel_paddr)
start = (vaddr_t)g_kernel_end - KERNEL_OFFSET + g_boot_info.kernel_paddr;
if (auto rem = start % PAGE_SIZE)
start += PAGE_SIZE - rem;

5
kernel/kernel/Memory/kmalloc.cpp
View File

@@ -1,9 +1,8 @@
#include <BAN/Errors.h>
#include <kernel/kprint.h>
#include <kernel/BootInfo.h>
#include <kernel/Memory/kmalloc.h>
#include <kernel/Thread.h>
#define MB (1 << 20)
extern uint8_t g_kernel_end[];
@@ -424,7 +423,7 @@ BAN::Optional<Kernel::paddr_t> kmalloc_paddr_of(Kernel::vaddr_t vaddr)
using namespace Kernel;
if ((vaddr_t)s_kmalloc_storage <= vaddr && vaddr < (vaddr_t)s_kmalloc_storage + sizeof(s_kmalloc_storage))
return V2P(vaddr);
return vaddr - KERNEL_OFFSET + g_boot_info.kernel_paddr;
return {};
}