RE: I write a patch for Japanese NEC i386 old computers.

[Hitoshi Ozeki]

Hello, all

Appendix: memory map of GRUB on NEC PC-9800 series.

At most machines have only one hardware mode, it is 'normal mode'.

[normal mode]

Start   End     Usage
0x000000        0x0003FF        stack space of BIOS initial boot loader and
real mode interrupts
0x000400        0x0005FF        BIOS system common area(BIOS parameter and
workarea)
?       0x001FFF        Real mode stack
0x007C00        0x007FFF        Chainloader loads a bootloader temporary,
and boot.img uses here for data area.
0x008000        ?       GRUB kernel
?       0x01FFFF        Limit of bootloader(boot sector and its next sector
loaded lower than here)
0x068000        0x077FFF        Disk buffer
?       0x07FFFF        Protected mode stack
0x080000        ?       Heap
0x0A0000        0x0A7FFF        Console text RAM, CG(Character Generator)
window and NVRAM
0x0A8000        0x0BFFFF        Video RAM(RGB)
0x0C0000        0x0DFFFF        extended BIOS ROM
0x0E0000        0x0E7FFF        Video RAM(E).
0x0E8000        0x0FFFFF        BIOS ROM

Few machines have two hardware mode, normal mode and high-rezo mode.

[high-resolution(high-rezo) mode]

Start   End     Usage
0x000000        0x0003FF        stack space of BIOS initial boot loader and
real mode interrupts
0x000400        0x0005FF        BIOS system common area(BIOS parameter and
workarea)
?       0x001FFF        Real mode stack
0x007C00        0x007FFF        Chainloader loads a bootloader temporary,
and boot.img uses here for data area.
0x008000        ?       GRUB kernel
?       0x01FFFF        Limit of bootloader(boot sector and its next sector
loaded lower than here)
0x068000        0x077FFF        Disk buffer
?       0x07FFFF        Protected mode stack
0x080000        0x0BFFFF        protected mode memory window
0x0C0000        0x0CFFFF        I forget.
0x0D0000        0x0DFFFF        extended BIOS ROM
0x0E0000        0x0E7FFF        Console text RAM, CG(Character Generator)
window and NVRAM
0x0E8000        0x0EFFFF        I forget.
0x0F0000        0x0FFFFF        BIOS ROM

Regards.

-- 
 Hitoshi Ozeki address@hidden