tyler.durden
/
kernel
mirror of https://github.com/FDOS/kernel.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

boot32, boot32lb: fix and update memory layout maps

This commit is contained in:
E. C. Masloch 2024-02-06 20:36:09 +01:00 committed by Kenneth J Davis
parent 2aa51a1992
commit ef10fa11e3
2 changed files with 44 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
boot/boot32.asm
View File

@ -1,31 +1,30 @@
; +--------+
; | |
; | |
; |--------| 4000:0000
; | |
; | FAT |
; | |
; |--------| 2000:0000
; |BOOT SEC|
; |RELOCATE|
; |--------| 1FE0:0000
; | |
; | |
; | |
; | |
; |--------|
; |BOOT SEC|
; |ORIGIN | 07C0:0000
; |--------|
; | |
; | |
; | |
; |--------|
; |KERNEL |
; |LOADED |
; |--------| 0060:0000
; | |
; +--------+
; Memory layout for the FreeDOS FAT32 single stage boot process:
;
; ...
; |-------| 1FE0h:7E00h = 27C00h (159 KiB)
; |BOOTSEC| loader relocates itself here first thing,
; |RELOC. | before loading root directory/FAT/kernel file
; |-------| 1FE0h:7C00h = 27A00h (158 KiB)
; | STACK | below relocated loader, above FAT sector (size 22 KiB)
; ...
; |-------| 2200h:2000h = 24000h (144 KiB)
; | FAT | (only 1 sector buffered, maximum sector size 8 KiB)
; |-------| 2200h:0000h = 22000h (136 KiB)
; ...
; |-------| 0000h:7E00h = 07E00h (31.5 KiB)
; |BOOTSEC| overwritten by the kernel, so the
; |ORIGIN | bootsector relocates itself up...
; |-------| 0000h:7C00h = 07C00h (31 KiB)
; ...
; |-------|
; |KERNEL | maximum size 128 KiB (overwrites bootsec origin)
; |LOADED | (holds 1 sector directory buffer before kernel file load)
; |-------| 0060h:0000h = 00600h (1.5 KiB)
; ...
; The kernel load segment may be patched using the SYS /L switch.
; We support values between 0x60 and 0x200 here, with file size
; of up to 128 KiB (rounded to cluster size). Default is 0x60.
;%define MULTI_SEC_READ 1

30
boot/boot32lb.asm
View File

@ -27,27 +27,31 @@
; Memory layout for the FreeDOS FAT32 single stage boot process:
;
; ...
; |-------| 1FE0:7E00
; |BOOTSEC|
; |RELOC. |
; |-------| 1FE0:7C00
; |-------| 1FE0h:7E00h = 27C00h (159 KiB)
; |BOOTSEC| loader relocates itself here first thing,
; |RELOC. | before loading root directory/FAT/kernel file
; |-------| 1FE0h:7C00h = 27A00h (158 KiB)
; | STACK | below relocated loader, above FAT sector (size 22 KiB)
; ...
; |-------| 2000:0200
; | FAT | (only 1 sector buffered)
; |-------| 2000:0000
; |-------| 2200h:2000h = 24000h (144 KiB)
; | FAT | (only 1 sector buffered, maximum sector size 8 KiB)
; |-------| 2200h:0000h = 22000h (136 KiB)
; ...
; |-------| 0000:7E00
; |-------| 0000h:7E00h = 07E00h (31.5 KiB)
; |BOOTSEC| overwritten by the kernel, so the
; |ORIGIN | bootsector relocates itself up...
; |-------| 0000:7C00
; |-------| 0000h:7C00h = 07C00h (31 KiB)
; ...
; |-------|
; |KERNEL | maximum size 134k (overwrites bootsec origin)
; |LOADED | (holds 1 sector directory buffer before kernel load)
; |-------| 0060:0000
; |KERNEL | maximum size 128 KiB (overwrites bootsec origin)
; |LOADED | (holds 1 sector directory buffer before kernel file load)
; |-------| 0060h:0000h = 00600h (1.5 KiB)
; ...
; The kernel load segment may be patched using the SYS /L switch.
; We support values between 0x60 and 0x200 here, with file size
; of up to 128 KiB (rounded to cluster size). Default is 0x60.
segment .text