diff options
| author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-01 22:41:13 -0800 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-01 22:41:13 -0800 |
| commit | ce64fef18f4b0adc1e48a8d73f489fd410aea765 (patch) | |
| tree | 91d5feb1b4cbeadbf10ec061a659ba7286f74c16 /baremetal/boot.hex | |
| parent | cfeb71c898f066197d55264dca9120b9ff9f60b6 (diff) | |
| download | mu-ce64fef18f4b0adc1e48a8d73f489fd410aea765.tar.gz | |
7835
Diffstat (limited to 'baremetal/boot.hex')
| -rw-r--r-- | baremetal/boot.hex | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/baremetal/boot.hex b/baremetal/boot.hex index 6a14017d..6fa874c2 100644 --- a/baremetal/boot.hex +++ b/baremetal/boot.hex @@ -143,6 +143,20 @@ cd 13 # int 13h, BIOS disk service 0f 82 9b 00 # jump-if-carry disk_error [label] + # load two more tracks of disk into addresses [0x27400, 0x37000) + b4 02 # ah <- 2 # read sectors from disk + # dl comes conveniently initialized at boot time with the index of the device being booted + b5 00 # ch <- 0 # cylinder 0 + b6 02 # dh <- 2 # track 0 + b1 01 # cl <- 1 # first sector, 1-based + b0 7e # al <- 126 # number of sectors to read = 2*63 + # address to write sectors to = es:bx = 0x17800 + bb 80 17 # bx <- 0x1780 [label] + 8e c3 # es <- bx + bb 00 00 # bx <- 0 + cd 13 # int 13h, BIOS disk service + 0f 82 9b 00 # jump-if-carry disk_error [label] + # reset es bb 00 00 # bx <- 0 8e c3 # es <- bx @@ -172,9 +186,8 @@ ea 00 7d 08 00 # far jump to initialize_32bit_mode after setting cs to the record at offset 8 in the gdt (gdt_code) [label] # padding -# 76: - 00 00 00 00 00 00 00 00 00 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +# 8e: + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |