calculate memmap entry len, dump entries
This commit is contained in:
pantonshire committed
1 parent
fdf6d81b2e
commit
f4085f1069
2 files changed
+166
-23
No files matched your search
@@ -250,7 +250,11 @@ main:
|
||||
call mem_detect
|
||||
jc .mem_detect_fail
|
||||
|
||||
call print_memmap
|
||||
|
||||
.hlt_loop:
|
||||
hlt
|
||||
jmp .hlt_loop
|
||||
|
||||
.mem_detect_fail:
|
||||
panic PANIC_TYPE_MEM_DETECT
|
||||
@@ -605,6 +609,38 @@ nybble_to_hex_char:
|
||||
ret
|
||||
|
||||
|
||||
; Copy a null-terminated string from ds:cx to es:ax.
|
||||
; - es: output buffer segment
|
||||
; - ax: output buffer offset
|
||||
; - ds: input buffer segment
|
||||
; - cx: input buffer offset
|
||||
; Return:
|
||||
; - ax: the address of the null terminator that was written
|
||||
; Clobber: none
|
||||
strcpy:
|
||||
fnstart
|
||||
push si
|
||||
push di
|
||||
|
||||
mov di, ax
|
||||
mov si, cx
|
||||
|
||||
.loop:
|
||||
mov al, [si]
|
||||
mov es:[di], al
|
||||
test al, al
|
||||
jz .done
|
||||
inc si
|
||||
inc di
|
||||
jmp .loop
|
||||
|
||||
.done:
|
||||
mov ax, di
|
||||
pop di
|
||||
pop si
|
||||
fnret
|
||||
|
||||
|
||||
; Check whether the A20 line is enabled. Writes to the boot sector identifier.
|
||||
; Arguments: none
|
||||
; Return:
|
||||
@@ -711,10 +747,6 @@ enable_a20_intel_8042:
|
||||
|
||||
|
||||
mem_detect:
|
||||
%if MEMMAP_CAP < 1
|
||||
%error "memmap buffer too small"
|
||||
%endif
|
||||
|
||||
fnstart
|
||||
push es
|
||||
|
||||
@@ -731,39 +763,43 @@ mem_detect:
|
||||
xor ebx, ebx
|
||||
; Buffer (es:di)
|
||||
mov di, MEMMAP
|
||||
mov dword [di + 0x20], 0x1
|
||||
; Entry size
|
||||
mov ecx, MEMMAP_ENT_SIZE
|
||||
|
||||
.loop:
|
||||
cmp word [GLOBALS + MEMMAP_ENTRIES], MEMMAP_CAP
|
||||
jae .done
|
||||
|
||||
; Init extended field to 0x1 in case e820 doesn't populate it.
|
||||
mov dword [di + MEMMAP_ENT_FIELD_EXT], 0x1
|
||||
; Size of entry for e820 to write
|
||||
mov ecx, E820_ENTRY_SIZE
|
||||
; Magic number
|
||||
mov edx, E820_MAGIC
|
||||
; Detect memory
|
||||
mov eax, 0xe820
|
||||
clc
|
||||
int 0x15
|
||||
jc .fail
|
||||
; Carry flag will be set if we'd already reached the end of the entries.
|
||||
jc .done
|
||||
|
||||
; Test magic number
|
||||
cmp eax, E820_MAGIC
|
||||
jne .fail
|
||||
|
||||
inc word [GLOBALS + MEMMAP_ENTRIES]
|
||||
|
||||
.loop:
|
||||
cmp word [GLOBALS + MEMMAP_ENTRIES], MEMMAP_CAP
|
||||
jae .done
|
||||
|
||||
add di, MEMMAP_ENT_SIZE
|
||||
mov dword [di + 0x20], 0x1
|
||||
mov ecx, MEMMAP_ENT_SIZE
|
||||
mov eax, 0xe820
|
||||
clc
|
||||
int 0x15
|
||||
; Carry flag will be set if we'd already reached the end of the entries.
|
||||
jc .done
|
||||
|
||||
inc word [GLOBALS + MEMMAP_ENTRIES]
|
||||
; Calculate and cache the entry end address.
|
||||
mov eax, [di + MEMMAP_ENT_FIELD_BASE]
|
||||
add eax, [di + MEMMAP_ENT_FIELD_LEN]
|
||||
mov [di + MEMMAP_ENT_FIELD_END], eax
|
||||
mov eax, [di + MEMMAP_ENT_FIELD_BASE + 4]
|
||||
adc eax, [di + MEMMAP_ENT_FIELD_LEN + 4]
|
||||
mov [di + MEMMAP_ENT_FIELD_END + 4], eax
|
||||
|
||||
; e820 _may_ return ebx=0 once we reach the last entry.
|
||||
test ebx, ebx
|
||||
jz .done
|
||||
|
||||
add di, MEMMAP_ENT_SIZE
|
||||
jmp .loop
|
||||
|
||||
.fail:
|
||||
@@ -771,6 +807,9 @@ mem_detect:
|
||||
jmp .return
|
||||
|
||||
.done:
|
||||
mov ax, [GLOBALS + MEMMAP_ENTRIES]
|
||||
test ax, ax
|
||||
jz .fail
|
||||
clc
|
||||
|
||||
.return:
|
||||
@@ -778,12 +817,107 @@ mem_detect:
|
||||
fnret
|
||||
|
||||
|
||||
print_memmap:
|
||||
fnstart
|
||||
|
||||
sub sp, VGA_WIDTH
|
||||
push eax
|
||||
push ebx
|
||||
push ecx
|
||||
push edx
|
||||
|
||||
mov si, MEMMAP
|
||||
mov dx, [GLOBALS + MEMMAP_ENTRIES]
|
||||
|
||||
.loop:
|
||||
test dx, dx
|
||||
jz .done
|
||||
dec dx
|
||||
|
||||
push es
|
||||
mov ax, ss
|
||||
mov es, ax
|
||||
|
||||
; Calculate region end
|
||||
; mov eax, [si]
|
||||
; mov ecx, [si + 8]
|
||||
; add eax, ecx
|
||||
; push eax
|
||||
; mov eax, [si + 4]
|
||||
; mov eax, [si + 12]
|
||||
; adc eax, ecx
|
||||
; push eax
|
||||
|
||||
lea ax, [bp - VGA_WIDTH]
|
||||
|
||||
mov cx, msg_memmap_base
|
||||
call strcpy
|
||||
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_BASE + 4]
|
||||
call dump_reg
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_BASE]
|
||||
call dump_reg
|
||||
|
||||
mov cx, msg_sep
|
||||
call strcpy
|
||||
mov cx, msg_memmap_len
|
||||
call strcpy
|
||||
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_LEN + 4]
|
||||
call dump_reg
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_LEN]
|
||||
call dump_reg
|
||||
|
||||
mov cx, msg_sep
|
||||
call strcpy
|
||||
mov cx, msg_memmap_end
|
||||
call strcpy
|
||||
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_END + 4]
|
||||
call dump_reg
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_END]
|
||||
call dump_reg
|
||||
|
||||
mov cx, msg_sep
|
||||
call strcpy
|
||||
mov cx, msg_memmap_type
|
||||
call strcpy
|
||||
|
||||
mov ecx, [si + MEMMAP_ENT_FIELD_TYPE]
|
||||
call dump_reg
|
||||
|
||||
mov bx, ax
|
||||
mov byte [bx], 0
|
||||
|
||||
lea ax, [bp - VGA_WIDTH]
|
||||
call vga_println
|
||||
|
||||
pop es
|
||||
add si, MEMMAP_ENT_SIZE
|
||||
jmp .loop
|
||||
|
||||
.done:
|
||||
pop edx
|
||||
pop ecx
|
||||
pop ebx
|
||||
pop eax
|
||||
add sp, VGA_WIDTH
|
||||
fnret
|
||||
|
||||
|
||||
msg_boot1_loaded db "boot1 loaded. hello!", 0
|
||||
msg_a20_enabled db "a20 enabled", 0
|
||||
msg_a20_disabled db "a20 not enabled", 0
|
||||
msg_a20_8042 db "trying 8042", 0
|
||||
msg_panic db "panic!", 0
|
||||
|
||||
msg_sep db ",", 0
|
||||
msg_memmap_base db "base=", 0
|
||||
msg_memmap_end db "end=", 0
|
||||
msg_memmap_len db "len=", 0
|
||||
msg_memmap_type db "type=", 0
|
||||
msg_memmap_ext db "ext=", 0
|
||||
|
||||
msg_reg_eip db "eip", 0
|
||||
msg_reg_eax db "eax", 0
|
||||
msg_reg_ebx db "ebx", 0
|
||||
|
||||
@@ -3,7 +3,7 @@
|
||||
|
||||
%define MEMMAP 0x6a00
|
||||
%define MEMMAP_END BOOT0_LOADPOINT
|
||||
%define MEMMAP_ENT_SIZE 24
|
||||
%define MEMMAP_ENT_SIZE 32
|
||||
%define MEMMAP_CAP ((MEMMAP_END - MEMMAP) / MEMMAP_ENT_SIZE)
|
||||
|
||||
%define GLOBALS 0x4000
|
||||
@@ -33,6 +33,15 @@
|
||||
|
||||
; ASCII string "SMAP", which is used by e820 as a magic number argument and return value.
|
||||
%define E820_MAGIC 0x534d4150
|
||||
; Size of entry returned by e820. This is less than MEMMAP_ENT_SIZE because we add some fields of
|
||||
; our own.
|
||||
%define E820_ENTRY_SIZE 24
|
||||
|
||||
%define MEMMAP_ENT_FIELD_BASE 0x00
|
||||
%define MEMMAP_ENT_FIELD_LEN 0x08
|
||||
%define MEMMAP_ENT_FIELD_TYPE 0x10
|
||||
%define MEMMAP_ENT_FIELD_EXT 0x14
|
||||
%define MEMMAP_ENT_FIELD_END 0x18
|
||||
|
||||
; boot0 base stack frame variable offsets / globals
|
||||
; (we use the same offsets once we copy the variables to the globals section)
|
||||
|
||||
Reference in new issue
Block a user