multiboot: Support arbitrary number of modules
Signed-off-by: Adam Lackorzynski <address@hidden>
---
hw/pc.c | 216 +++++++++++++++++++++++++++++++++++++++++---------------------
1 files changed, 143 insertions(+), 73 deletions(-)
diff --git a/hw/pc.c b/hw/pc.c
index 6bcfe1b..163bec1 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -507,6 +507,79 @@ static long get_file_size(FILE *f)
#error multiboot struct needs to fit in 16 bit real mode
#endif
+enum {
+ /* Multiboot info */
+ MBI_FLAGS = 0,
+ MBI_MEM_LOWER = 4,
+ MBI_MEM_UPPER = 8,
+ MBI_BOOT_DEVICE = 12,
+ MBI_CMDLINE = 16,
+ MBI_MODS_COUNT = 20,
+ MBI_MODS_ADDR = 24,
+ MBI_MMAP_ADDR = 48,
+
+ MBI_SIZE = 88,
+
+ /* Multiboot modules */
+ MB_MOD_START = 0,
+ MB_MOD_END = 4,
+ MB_MOD_CMDLINE = 8,
+
+ MB_MOD_SIZE = 16,
+
+ /* Region offsets */
+ ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
+ ADDR_MBI = ADDR_E820_MAP + 0x500,
+
+ /* Multiboot flags */
+ MULTIBOOT_FLAGS_MEMORY = 1 << 0,
+ MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
+ MULTIBOOT_FLAGS_CMDLINE = 1 << 2,
+ MULTIBOOT_FLAGS_MODULES = 1 << 3,
+ MULTIBOOT_FLAGS_MMAP = 1 << 6,
+};
+
+struct mb_state {
+ void *mb_buf; /* buffer holding kernel, cmdlines and mb_infos */
+ uint32_t mb_buf_phys; /* address in target */
+ int mb_buf_size; /* size of mb_buf in bytes */
+ int mb_mods_avail; /* available slots for mb modules infos */
+ int mb_mods_count; /* currently used slots of mb modules */
+ int offset_mbinfo; /* offset of mb-info's in bytes */
+ int offset_cmdlines; /* offset in buffer for cmdlines */
+ int offset_mods; /* offset of modules in bytes */
+};
+static uint32_t mb_add_cmdline(struct mb_state *s, const char *cmdline)
+{
+ int len = strlen(cmdline) + 1;
+ uint32_t p = s->offset_cmdlines;
+
+ pstrcpy((char *)s->mb_buf + p, len, cmdline);
+ s->offset_cmdlines += len;
+ return s->mb_buf_phys + p;
+}
+
+static void mb_add_mod(struct mb_state *s,
+ uint32_t start, uint32_t end,
+ uint32_t cmdline_phys)
+{
+ char *p;
+ assert(s->mb_mods_count < s->mb_mods_avail);
+
+ p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;
+
+ stl_p(p + MB_MOD_START, start);
+ stl_p(p + MB_MOD_END, end);
+ stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
+
+#ifdef DEBUG_MULTIBOOT
+ fprintf(stderr, "mod%02d: %08x - %08x\n", s->mb_mods_count, start, end);
+#endif
+ s->mb_mods_count++;
+}
+
static int load_multiboot(void *fw_cfg,
FILE *f,
const char *kernel_filename,
@@ -519,12 +592,8 @@ static int load_multiboot(void *fw_cfg,
uint32_t mh_entry_addr;
uint32_t mh_load_addr;
uint32_t mb_kernel_size;
- uint32_t mmap_addr = MULTIBOOT_STRUCT_ADDR;
- uint32_t mb_bootinfo = MULTIBOOT_STRUCT_ADDR + 0x500;
- uint32_t mb_mod_end;
- uint8_t bootinfo[0x500];
- uint32_t cmdline = 0x200;
- uint8_t *mb_kernel_data;
+ struct mb_state mbs;
+ uint8_t bootinfo[MBI_SIZE];
uint8_t *mb_bootinfo_data;
/* Ok, let's see if it is a multiboot image.
@@ -549,6 +618,7 @@ static int load_multiboot(void *fw_cfg,
fprintf(stderr, "qemu: I believe we found a multiboot image!\n");
#endif
memset(bootinfo, 0, sizeof(bootinfo));
+ memset(&mbs, 0, sizeof(mbs));
if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
fprintf(stderr, "qemu: multiboot knows VBE. we don't.\n");
@@ -566,8 +636,8 @@ static int load_multiboot(void *fw_cfg,
mh_load_addr = mh_entry_addr = elf_entry;
mb_kernel_size = kernel_size;
- mb_kernel_data = qemu_malloc(mb_kernel_size);
- if (rom_copy(mb_kernel_data, elf_entry, kernel_size) != kernel_size) {
+ mbs.mb_buf = qemu_malloc(mb_kernel_size);
+ if (rom_copy(mbs.mb_buf, elf_entry, kernel_size) != kernel_size) {
fprintf(stderr, "Error while fetching elf kernel from rom\n");
exit(1);
}
@@ -604,104 +674,104 @@ static int load_multiboot(void *fw_cfg,
mb_kernel_size, mh_load_addr);
#endif
- mb_kernel_data = qemu_malloc(mb_kernel_size);
+ mbs.mb_buf = qemu_malloc(mb_kernel_size);
fseek(f, mb_kernel_text_offset, SEEK_SET);
- fread(mb_kernel_data, 1, mb_kernel_size, f);
+ fread(mbs.mb_buf, 1, mb_kernel_size, f);
fclose(f);
}
- /* blob size is only the kernel for now */
- mb_mod_end = mh_load_addr + mb_kernel_size;
+ mbs.mb_buf_phys = mh_load_addr;
+
+ mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
+ mbs.offset_mbinfo = mbs.mb_buf_size;
+
+ /* Calculate space for cmdlines and mb_mods */
+ mbs.mb_buf_size += strlen(kernel_filename) + 1;
+ mbs.mb_buf_size += strlen(kernel_cmdline) + 1;
+ if (initrd_filename) {
+ const char *r = initrd_filename;
+ mbs.mb_buf_size += strlen(r) + 1;
+ mbs.mb_mods_avail = 1;
+ while ((r = strchr(r, ','))) {
+ mbs.mb_mods_avail++;
+ r++;
+ }
+ mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
+ }
+
+ mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
+
+ // enlarge mb_buf to hold cmdlines and mb-info structs