From 3aefeeb723b8822916fb39b7c32551c35c06e32f Mon Sep 17 00:00:00 2001 From: Alejandro Sior Date: Sat, 21 May 2022 14:04:42 +0200 Subject: boot: reorganize bios and drive modules --- bios/drive/drive.ha | 71 ----------------------------------------------------- 1 file changed, 71 deletions(-) delete mode 100644 bios/drive/drive.ha (limited to 'bios/drive/drive.ha') diff --git a/bios/drive/drive.ha b/bios/drive/drive.ha deleted file mode 100644 index a2992b8..0000000 --- a/bios/drive/drive.ha +++ /dev/null @@ -1,71 +0,0 @@ -use bios; - -def sector_size: u32 = 512; - -export type error = !void; - -// Converts lba to the CHS format -fn lbatochs(lba: u32) (u16, u16, u16) = { - const temp = lba / bios::drive_sectors_per_track; - const sector = (lba % bios::drive_sectors_per_track) + 1; - const head = temp % bios::drive_heads; - const cylinder = temp / bios::drive_heads; - - return (cylinder: u16, head: u16, sector: u16); -}; - -// Reads the sector at lba and place it into the workspace buffer -fn bios_read(lba: u32) (void | error) = { - const chs = lbatochs(lba); - const readcount = len(bios::ws): u32 / sector_size; - - // AH=0x2 (read disk) AL=1 (read 1 sector) - bios::regs.eax = 0x2 << 8 | readcount; - - // CH=cylinder CL=sector - bios::regs.ecx = chs.0 << 8 | chs.2; - - // DH=head DL=driveno - bios::regs.edx = chs.1 << 8 | bios::drive_number; - - let ws = (&bios::ws): uintptr; - bios::regs.es = (ws / 16): u16; - bios::regs.ebx = (ws % 16): u32; - - bios::call(0x13); - - if (bios::regs.eax != readcount) { - return error; - }; -}; - -export fn read(addr: u32, count: size, dest: *[*]u8) (void | error) = { - // the amount of sectors fitting in the workspace (cannot be make a global constant yet, an assertion fails) - const readcount = len(bios::ws): u32 / sector_size; - - // the starting lba - let lba = addr / sector_size; - // the reading head (for starting to read bytes not aligned with the sector) - let head = addr % len(bios::ws); - - let cursor = 0z; - - for (true) { - bios_read(lba)?; - - for (head < len(bios::ws)) { - // XXX: use memmove - dest[cursor] = bios::ws[head]; - - head += 1; - cursor += 1; - if (cursor >= count) { - return; - }; - }; - - head = 0; - lba += readcount; - }; - -}; -- cgit v1.2.3