Support booting such image by parsing header as per Linux's
specification [1].
This enabled booting vmlinux.efi/vmlinuz.efi shipped by
distros without supplying BIOS.
[1]: https://docs.kernel.org/arch/loongarch/booting.html
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
hw/loongarch/boot.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/hw/loongarch/boot.c b/hw/loongarch/boot.c
index
93847b0eaf8e50ce1a990b91267780e6785e1c2f..38c19bffa3475d61ffab27a26af9c4c821769dca
100644
--- a/hw/loongarch/boot.c
+++ b/hw/loongarch/boot.c
@@ -16,6 +16,26 @@
#include "sysemu/reset.h"
#include "sysemu/qtest.h"
+/*
+ * Linux Image Format
+ * https://docs.kernel.org/arch/loongarch/booting.html
+ */
+#define LINUX_PE_MAGIC 0x818223cd
+#define MZ_MAGIC 0x5a4d /* "MZ" */
+
+struct loongarch_linux_hdr {
+ uint32_t mz_magic;
+ uint32_t res0;
+ uint64_t kernel_entry;
+ uint64_t kernel_size;
+ uint64_t load_offset;
+ uint64_t res1;
+ uint64_t res2;
+ uint64_t res3;
+ uint32_t linux_pe_magic;
+ uint32_t pe_header_offset;
+} QEMU_PACKED;
+
struct memmap_entry *memmap_table;
unsigned memmap_entries;
@@ -260,6 +280,50 @@ static uint64_t cpu_loongarch_virt_to_phys(void *opaque, uint64_t addr)
return addr & MAKE_64BIT_MASK(0, TARGET_PHYS_ADDR_SPACE_BITS);
}
+static int64_t load_loongarch_linux_image(const char *filename,
+ uint64_t *kernel_entry,
+ uint64_t *kernel_low,
+ uint64_t *kernel_high)
+{
+ gsize len;
+ ssize_t size;
+ uint8_t *buffer;
+ struct loongarch_linux_hdr *hdr;
+
+ /* Load as raw file otherwise */
+ if (!g_file_get_contents(filename, (char **)&buffer, &len, NULL)) {
+ return -1;
+ }
+ size = len;
+
+ /* Unpack the image if it is a EFI zboot image */
+ if (unpack_efi_zboot_image(&buffer, &size) < 0) {
+ g_free(buffer);
+ return -1;
+ }
+
+ hdr = (struct loongarch_linux_hdr *)buffer;
+
+ if (extract32(le32_to_cpu(hdr->mz_magic), 0, 16) != MZ_MAGIC ||
+ le32_to_cpu(hdr->linux_pe_magic) != LINUX_PE_MAGIC) {
+ g_free(buffer);
+ return -1;
+ }
+
+ /* Early kernel versions may have those fields in virtual address */
+ *kernel_entry = extract64(le64_to_cpu(hdr->kernel_entry),
+ 0, TARGET_PHYS_ADDR_SPACE_BITS);
+ *kernel_low = extract64(le64_to_cpu(hdr->load_offset),
+ 0, TARGET_PHYS_ADDR_SPACE_BITS);
+ *kernel_high = *kernel_low + size;
+
+ rom_add_blob_fixed(filename, buffer, size, *kernel_low);
+
+ g_free(buffer);
+
+ return size;
+}
+
static int64_t load_kernel_info(struct loongarch_boot_info *info)
{
uint64_t kernel_entry, kernel_low, kernel_high;
@@ -270,6 +334,11 @@ static int64_t load_kernel_info(struct loongarch_boot_info
*info)
&kernel_entry, &kernel_low,
&kernel_high, NULL, 0,
EM_LOONGARCH, 1, 0);
+ if (kernel_size < 0) {
+ kernel_size = load_loongarch_linux_image(info->kernel_filename,
+ &kernel_entry, &kernel_low,
+ &kernel_high);
+ }
if (kernel_size < 0) {
error_report("could not load kernel '%s': %s",