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soc:2009:lynusvaz:journal:week6 [2009/07/02 01:34] lynusvaz |
soc:2009:lynusvaz:journal:week6 [2009/07/03 23:50] lynusvaz |
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| * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=e3374c796add6926718bbe2a67fe557e4a89cb5f|Remove size field from struct generic_stack]] | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=e3374c796add6926718bbe2a67fe557e4a89cb5f|Remove size field from struct generic_stack]] | ||
| + | July 2: Continued with yesterday's idea, and decided to see if using macros to inline the code would lead to some savings. The obvious code, allocating memory on the heap, did not offer any size changes. However, using arrays led to a decrease of around 0.5KB. But, doing so leads to a limit on features that use the stack: nesting of branches and loops, the number of arguments in a command, and the number of lines in a script. The first two could be solved by setting the limit high enough, but the last may be a problem. So, since the framework for lists is already present in <gpxe/lists.h>, I decided to store the commands using a list: | ||
| + | struct command_entry { | ||
| + | struct list_head neighbours; | ||
| + | char line[1]; | ||
| + | }; | ||
| + | The command_entry is allocated as malloc(sizeof(struct command_entry) + strlen(command)). This required some modification to the program counter. The loop information stored on the loop stack now stores a pointer to a command_entry struct stored in the heap. The prog_ctr variable is also replaced by a cur_command pointer, which points to the currently-executing command. | ||
| + | Today's commits: | ||
| + | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=a0ee6ba8b094e49f62d40d473d860806a870e0c4|Macros on dynamically-allocated arrays]] | ||
| + | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=ecc1283ac0266f2bd4a033a23c017697d4f1c8d0|Macros on static arrays]] | ||
| + | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=7815aecdab93649a3e80efa50ccf4787aa02f0b7|Using lists]] | ||
| + | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=dfd9803e73cc9d4b332c741ef1cc59c9fd6c0a19|Remove the prog_ctr variable]] | ||
| + | |||
| + | July 3: While working on quoting, I had missed out incomplete lines, for example: | ||
| + | gPXE>echo "Hello | ||
| + | >World" | ||
| + | gPXE>echo Hello \ | ||
| + | >World | ||
| + | So I worked on this today. The idea is that I have a global variable that is set once the line is found to be incomplete. In the system() function, execv() is called with only complete lines, and the space used for the command is freed. Else, the command is kept stored in a static variable, and on the next call to system(), the new command is appended to the old one. The entire string is then parsed as usual. | ||
| + | * [[http://git.etherboot.org/?p=people/lynusvaz/gpxe.git;a=commit;h=5bb4f424aaca9ede019a6981fae5fc09d5a4f096| Detect incomplete lines]] | ||
