diff options
| -rw-r--r-- | 400.mu | 1 | ||||
| -rw-r--r-- | boot.subx | 89 | ||||
| -rw-r--r-- | shell/sandbox.mu | 3 |
3 files changed, 93 insertions, 0 deletions
diff --git a/400.mu b/400.mu index 2f7896c8..2a0be7cf 100644 --- a/400.mu +++ b/400.mu @@ -10,6 +10,7 @@ sig read-key kbd: (addr keyboard) -> _/eax: byte # disk sig load-first-sector-from-primary-bus-secondary-drive out: (addr stream byte) +sig store-first-sector-to-primary-bus-secondary-drive out: (addr stream byte) # tests sig count-test-failure diff --git a/boot.subx b/boot.subx index 200f201a..028862ad 100644 --- a/boot.subx +++ b/boot.subx @@ -971,6 +971,91 @@ $load-first-sector-from-primary-bus-secondary-drive:end: 5d/pop-to-ebp c3/return +store-first-sector-to-primary-bus-secondary-drive: # in: (addr stream byte) + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # . save registers + 50/push-eax + 51/push-ecx + 52/push-edx + 53/push-ebx + # check for drive + (secondary-drive-exists?) # => eax + 3d/compare-eax-and 0/imm32/false + 0f 84/jump-if-= $store-first-sector-to-primary-bus-secondary-drive:end/disp32 + # kick off write + (ata-drive-select 0xf0) # primary bus, secondary drive; 4 LSBs contain 4 upper bits of LBA (here 0) + (clear-ata-error) + (ata-sector-count 1) + (ata-lba 0 0 0) # lower 24 bits of LBA, all 0 + (ata-command 0x30) # write sectors with retries + # wait + (while-ata-busy) + (until-ata-ready-for-data) + # send data + ba/copy-to-edx 0x1f0/imm32 + b9/copy-to-ecx 0x200/imm32 # 512 bytes per sector + # var first-byte/ebx: byte + # when it's more than 0xff, we're at an even-numbered byte + bb/copy-to-ebx 0xffff/imm32 +$store-first-sector-to-primary-bus-secondary-drive:loop: + { + 81 7/subop/compare %ecx 0/imm32 + 74/jump-if-= break/disp8 + # this loop is slow, but the ATA spec also requires a small delay + (stream-empty? *(ebp+8)) # => eax + 3d/compare-eax-and 0/imm32/false + 75/jump-if-!= break/disp8 + # read byte from stream + (read-byte *(ebp+8)) # => eax + # if we're at an odd-numbered byte, save it to first-byte + 81 7/subop/compare %ebx 0xff/imm32 + { + 7e/jump-if-<= break/disp8 + 89/<- %ebx 0/r32/eax + eb/jump $store-first-sector-to-primary-bus-secondary-drive:loop/disp8 + } + # otherwise OR it with first-byte and write it out + c1/shift 4/subop/left %eax 8/imm8 + 09/or %eax 3/r32/ebx + 66 ef/write-ax-into-port-dx + 49/decrement-ecx + 49/decrement-ecx + # reset first-byte + bb/copy-to-ebx 0xffff/imm32 + eb/jump loop/disp8 + } + # write out first-byte if necessary + 81 7/subop/compare %ebx 0xff/imm32 + { + 7f/jump-if-> break/disp8 + 89/<- %eax 3/r32/ebx + 66 ef/write-ax-into-port-dx + 49/decrement-ecx + 49/decrement-ecx + } + # pad zeroes + 31/xor %eax 0/r32/eax + { + 81 7/subop/compare %ecx 0/imm32 + 74/jump-if-= break/disp8 + 66 ef/write-ax-into-port-dx + 49/decrement-ecx + 49/decrement-ecx + eb/jump loop/disp8 + } +$store-first-sector-to-primary-bus-secondary-drive:end: + # . restore registers + 5b/pop-to-ebx + 5a/pop-to-edx + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + secondary-drive-exists?: # -> _/eax: boolean # . prologue 55/push-ebp @@ -1205,4 +1290,8 @@ $while-ata-busy:end: # . epilogue c3/return +until-ata-ready-for-data: + (until-ata-data-available) + c3/return + # vim:ft=subx diff --git a/shell/sandbox.mu b/shell/sandbox.mu index 46dc21f1..5278e708 100644 --- a/shell/sandbox.mu +++ b/shell/sandbox.mu @@ -130,6 +130,9 @@ fn edit-sandbox _self: (addr sandbox), key: byte { var trace/eax: (addr trace) <- lookup *trace-ah clear-trace trace run data, value, trace + # testing write to disk +#? rewind-stream value +#? store-first-sector-to-primary-bus-secondary-drive value return } # tab |